Mining with Seasonic Power Supplies!

Enclosures, modding, blowholes, and the power needed to run it all.

Moderators: Nemesis, SpotTheCat

Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 1:41 am

So, I know you guys love me hating on your well known brands with my taboo mining experience, so I've brought you more. The 7970 XFX fans I've mentioned a few months ago are still failing. I initially had one of the two fans on the cards fail, now the other one on the opposite side are now failing. The XFX 280s I have are now beginning to fail (fans), they're beginning to wobble, but it took them a lot longer then the 7970s with the metal caps in the middle.

Anyway, that's not the reason I'm here. I bought two Seasonsic power supplies on completely different occasions at completely different points in time for completely different reasons. The first one was a Seasonic X650 I bought last year. My computer began to have sporadic issues and I eventually conceded it may be the power supply, so I purchased a new one (the x650). This spring I upgraded from a 7870 to a R9-290 and I began to have micro-stuttering issues with my R9-290 and eventually after trying quite a few different things, finally replaced the power supply with one from one of my miners (a EVGA). Upon pulling the connectors out, I noticed one was really snug and ended up yanking it out with a pair of pliers. Low and behold the connector fused with the power supply plastic. Beware, the following pictures are not for the feint of heart or lover of Seasonic.

http://i.imgur.com/e0zCpfs.jpg
http://i.imgur.com/tqXOOUe.jpg
http://i.imgur.com/QZtNqGO.jpg

I thought 'whatever, (1)R9-290 is horrible and sucks a lot of juice as I was only using one of the cables' and moved it to a miner after cleaning up the connections and removing plastic, attached another one of the 8 pin GPU cables and let it run (this time on a R9-280x with two cables). I didn't have time to RMA it and it seemed to function fine after cleaning the connector. Keep in mind, this was on my desktop and no mining took place on my desktop.

In the meantime one of my miners seemed to be having sporadic issues with the graphics cards attached to it, this time with the Seasonic x850. I looked at the power connectors and inspected them (the end attached to the cards, which looked fine), eventually figuring it was the motherboard (a ASrock board I RMA'd after). I received the board back yesterday and started having similar issues. This time I pulled the plugs to find one of the plugs attached to a 7970 was melted. This further prompted me to check the PSU ends and one of the other plugs that was attached to a R9-290 had melted and fused once again next to the PSU.

http://i.imgur.com/QN0mgOq.jpg
http://i.imgur.com/shS57ch.jpg
http://i.imgur.com/MV3HUaf.jpg
http://i.imgur.com/aKJfjwQ.jpg
http://i.imgur.com/riRupwp.jpg
http://i.imgur.com/lPWEZ89.jpg

Each 8 pin connector is rated for 150w a piece, none of my other power supplies are showing symptoms such as this (Rosewill and eVGA of lower wattage and prices) with a single connector. This leads me to believe Seasonic is skimping on materials here. The connectors and pins on the video cards are fine (thank god), but as you can see the 850 is pretty much trashed and will need to be RMA'd. These cards haven't been OC'd past 300w a piece, I check my wattages with a kill-a-watt meter. This is ridiculous as these are not cheap PSUs. They were also not set to quiet mode either.

I know some of you are thinking 'But Bensam, why didn't you use two cables!'. The x850 only came with three, one I used for a 7970 and the other two for a R9-290. The x650 came with two, but didn't seem as though I needed it nor did it specify it. I also was not mining on the system with the x650. I have other PSUs as I mentioned before and their connectors are fine, showing no signs of degradation with one cable. They've all been mining for about the same amount of time. I should also point out I started having issues with my miner back in Febuaryish, which got progressively worse till last month the miner couldn't function with two of the four cards attached to it.
Bensam123
Gerbil Elite
 
Posts: 952
Joined: Wed May 29, 2002 12:19 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 2:10 am

Looks like the majority of the damage is on a single pin in each one of those connectors, always the same location as well.

Weird. Have you any other units that are built by Seasonic (but are not Seasonic branded) in your setup?

Definitely getting a bit difficult, but I would wonder if current distribution is uneven across the connector for some reason. IIRC it's about a 6 amp per pin maximum rating, and exceeding that on any single pin for extended periods would definitely lead to the issue you describe.
continuum
Gerbil First Class
Gold subscriber
 
 
Posts: 168
Joined: Mon Jun 09, 2003 1:42 am
Location: California

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 2:25 am

Googling around, this seems to be fairly common with Seasonic PSUs and lots of voltage (like mining, overclocking, or hardcore gaming). This also applies to built by Seasonic units as well (some corsair and coolermaster).

http://forums.hardwarezone.com.sg/corbe ... 89851.html
http://www.overclock.net/t/1461040/so-s ... -or-did-it
http://hardforum.com/showthread.php?t=1758618

It doesn't just apply to the PCI-E socket either as some people are melting the EPS connectors and the 24pin motherboard connector as well. My main PC has a 8350 in it, but it wasn't OC'd hardcore or anything and the EPS/24 pin connector are alright (although I didn't check the PSU connection to them).

It seems as though Seasonic is using low tolerance plastic (as it's right up to the spec, but can't tolerate much more heat). The wires never melt or get hot, just the connectors do and of course they coat everything in plastic so it either heats up or doesn't make a connection, further making the problem worse. It could very well be the batches are inconsistent as well, not being up to spec throughout the entire connector.

Either way, it seems as though they aren't testing them to their full capacity and people are now starting to reach that (mainly with mining).

I did go fondle my other 8+8 connectors on my other 7970/r9-280xs and they seem to be alright. Those systems use Rosewill Platinum PSUs.
Bensam123
Gerbil Elite
 
Posts: 952
Joined: Wed May 29, 2002 12:19 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 2:49 am

Hmm, looks like Rosewill uses ATNG, Superflower, and possibly others in their platinum units. No idea if ATNG or Superflower has any issues in the use you describe-- my brief seconds of searching wasn't enough to tell.

t doesn't just apply to the PCI-E socket either as some people are melting the EPS connectors and the 24pin motherboard connector as well
That's an old, familiar problem across lots of brands unfortunately. In my experience it's usually due to pushing the current margin across those connectors in a specific application (or applications)-- we have years' worth of some product lines with similar issues on Delta power supplies, other product lines with that issue on Supermicro motherboards, yet others on Tyan motherboards, burned up Zippy/Emacs PSU connectors, etc...

I did go fondle my other 8+8 connectors on my other 7970/r9-280xs and they seem to be alright. Those systems use Rosewill Platinum PSUs.
Were you able to check the PSU side of the connectors as well?

A very, very brief Google seems to show this issue is with AMD cards (R9 290X's and whatnot get mentioned the most), I wonder if additional research will show what other cards might be affected in sufficient numbers to establish any patterns of which cards seem to be involved the most-- and if they draw too much power across a single pin or not, or if it there is enough evidence out there to confirm a marginal PSU plug or cabling issue on Seasonic-- and is it poor quality plastic or a poor connection? (five or so threads shows it's always the same pin in the corner, maybe one shows a different pin, but as I said such a small sample doesn't tell us anything useful).
continuum
Gerbil First Class
Gold subscriber
 
 
Posts: 168
Joined: Mon Jun 09, 2003 1:42 am
Location: California

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 7:25 am

Interesting and mildly disturbing. One would imagine they're using the same plastic across all their products, but I wonder if modular PSUs are more susceptible.
i5 2500k - P67 - GTX660 - 840 Pro 256GB - Xonar Essence STX - Senn HD595's
The Egg
Gerbil Elite
Silver subscriber
 
 
Posts: 612
Joined: Sun Apr 06, 2008 4:46 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 8:13 am

That's the weird thing. I'd assume if the wire isn't heavy enough gauge we'd see melted wire and fires, but it's just the connector that melts. It's just the connector on the insertion end too. From all the photos I've seen, they haven't melted on the connecting ends except on the PSU itself. So like on my graphics card end, nothing melted or burned. The pins look fine (or it's on a graphics card that got shuffled :(). But the end that are burned on the PSU are both the insertion and the receptacle ends. Not just that, but the wire coating around the pins that were melted is fine, the pins themselves look fine except for melted plastic, it's only the connectors that seems to melt. I'd assume the wire coating would start melting before that plastic would. As far as I can remember, the wires have never felt hot either and I've had my hands all over my rigs when they're mining to do various things.

The Rosewill PSUs are hard wired in and the EVGA I have is fine.

This may not necessarily be Seasonic, but rather whoever makes these connectors. China loves cutting costs in whatever way possible, it's entirely possible that they're mixing bad things in with their plastic mix to make it cheaper.
Bensam123
Gerbil Elite
 
Posts: 952
Joined: Wed May 29, 2002 12:19 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 8:29 am

You were pulling 300W down a cable rated for 150W? Not smart, it quite easily could lead to a house fire. I hope you've learned your lesson now.

In an ideal world Seasonic would have a bigger safety factor for their cables in case people take liberties with them, but in a parallel ideal world people would read warnings and load ratings before using cables.
Intel Core i5-4670K | Asus Z87-A | G.Skill 8GB 2400MHz CL10 | Asus DirectCU II R9 290 4GB | Samsung 840 120GB |Thermalright Macho | Lancool PC-K59
puppetworx
Gerbil Elite
Silver subscriber
 
 
Posts: 521
Joined: Tue Dec 02, 2008 5:16 am

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 9:04 am

puppetworx wrote:You were pulling 300W down a cable rated for 150W? Not smart, it quite easily could lead to a house fire. I hope you've learned your lesson now.

In an ideal world Seasonic would have a bigger safety factor for their cables in case people take liberties with them, but in a parallel ideal world people would read warnings and load ratings before using cables.

I must've missed that part. If you were pulling double wattage through a connector, you can't fault the PSU for any problems.
i5 2500k - P67 - GTX660 - 840 Pro 256GB - Xonar Essence STX - Senn HD595's
The Egg
Gerbil Elite
Silver subscriber
 
 
Posts: 612
Joined: Sun Apr 06, 2008 4:46 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 9:35 am

Never have trusted seasonic.. mostly stick to cosair, evga, enermax psu's with single rail 12v lines and giant caps inside.
Cybert said: Capitlization and periods are hard for you, aren't they? I've given over $100 to techforums. I should have you banned for my money.
maxxcool
Gerbil Elite
Silver subscriber
 
 
Posts: 652
Joined: Thu Sep 12, 2002 8:40 am
Location: %^&*%$$

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 9:37 am

Wow, craziness. I have not seen that sort of thing since the days right before we went from 4-pin to 8-pin ATX12V (CPU power) connectors. IIRC there were a few incidents back then where people melted the 4-pin 12V connector on the motherboard; I believe the Tyan Tiger MPX was one of the boards known for this failure mode (fortunately I never got hit by it).

I don't think the plastic is at fault here. Even if it is a (relatively) low temperature thermoplastic, the contacts should not be getting anywhere near hot enough to cause that kind of damage.

Off the top of my head, I can think of several potential failure scenarios which could damage the power wiring like that:

1. Defective/damaged/contaminated electrical contact (either in the connector on the PSU, or the PSU end of the PCIe cable).

2. Modular cable not fully seated into the PSU connector.

3. Bad solder connections in the PSU, which were causing the current to be unevenly distributed between the wires in the PCIe connector.

4. Bad solder connections on the power connector of the GPU (basically same as #3, but at the other end).

5. Problem with the GPU which caused it to draw stupidly huge amounts of current.

IMO #1 is the most likely scenario. I consider #s 3-5 to be somewhat unlikely, since we'd probably see some damage at the GPU end as well (but might not, if the contacts inside the connector at the GPU end had lower resistance to begin with).

When you've got contacts that don't make a good connection and those contacts are carrying a lot of current, there's a positive feedback effect. Hot spots form in the areas where there's high electrical resistance, which damages the contact, leading to even more resistance and yet higher temperatures. Eventually things get hot enough that stuff starts to melt or burn.

TBH I'm not a huge fan of modular PSUs in general. The extra connector adds a bit of resistance (even when it isn't defective), and at the end of the day it is just one more potential point of failure. My philosophy has always been to just bundle the extra unused wires up and zip tie them into an empty drive bay.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 10:20 am

puppetworx wrote:You were pulling 300W down a cable rated for 150W? Not smart, it quite easily could lead to a house fire. I hope you've learned your lesson now.

In an ideal world Seasonic would have a bigger safety factor for their cables in case people take liberties with them, but in a parallel ideal world people would read warnings and load ratings before using cables.


Each connector is rated for 150w, yet they're what melted. None of the cables are stated that they're limited to 150w a piece (they also did not melt). If they were limited to 150w per cable they would be sending you cables that are 6+2 not 2x6+2 and adding warnings or information for such configurations. I checked the manual for what that's worth after noticing this and looked around a bit and saw no such warnings or load ratings.

http://www.seasonicusa.com/images/Broch ... Manual.pdf

just brew it! wrote:Wow, craziness. I have not seen that sort of thing since the days right before we went from 4-pin to 8-pin ATX12V (CPU power) connectors. IIRC there were a few incidents back then where people melted the 4-pin 12V connector on the motherboard; I believe the Tyan Tiger MPX was one of the boards known for this failure mode (fortunately I never got hit by it).

I don't think the plastic is at fault here. Even if it is a (relatively) low temperature thermoplastic, the contacts should not be getting anywhere near hot enough to cause that kind of damage.

Off the top of my head, I can think of several potential failure scenarios which could damage the power wiring like that:

1. Defective/damaged/contaminated electrical contact (either in the connector on the PSU, or the PSU end of the PCIe cable).

2. Modular cable not fully seated into the PSU connector.

3. Bad solder connections in the PSU, which were causing the current to be unevenly distributed between the wires in the PCIe connector.

4. Bad solder connections on the power connector of the GPU (basically same as #3, but at the other end).

5. Problem with the GPU which caused it to draw stupidly huge amounts of current.

IMO #1 is the most likely scenario. I consider #s 3-5 to be somewhat unlikely, since we'd probably see some damage at the GPU end as well (but might not, if the contacts inside the connector at the GPU end had lower resistance to begin with).

When you've got contacts that don't make a good connection and those contacts are carrying a lot of current, there's a positive feedback effect. Hot spots form in the areas where there's high electrical resistance, which damages the contact, leading to even more resistance and yet higher temperatures. Eventually things get hot enough that stuff starts to melt or burn.

TBH I'm not a huge fan of modular PSUs in general. The extra connector adds a bit of resistance (even when it isn't defective), and at the end of the day it is just one more potential point of failure. My philosophy has always been to just bundle the extra unused wires up and zip tie them into an empty drive bay.



Some of the posts mentioned the possibility of the connectors not being snug enough and in one case a Seasonic representative mentioned checking that, but it was OK (one of the posts I linked has a Seasonic representative talking in it).

These were brand new, it's hard to imagine only the Seasonic connectors would get dirty (by me)and only on certain cards. The other PSUs should be exhibiting similar signs. That leaves factory issued dirt? Keep in mind there was a year between both of these purchases and one was put into a gaming PC that wasn't mining and the other into a mining rig.

The connections were all snug...

It's a possibility that the R9-290s were drawing too much current. But in one case it was on my gaming PC, on the other two it was a R9-290 with two cables hooked up to it and a 7970. Those were mining pretty much 24/7, but I undervolt my cards, so it's hard to imagine these drawing more wattage then what you see in stress tests normally for the card.
Bensam123
Gerbil Elite
 
Posts: 952
Joined: Wed May 29, 2002 12:19 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 10:33 am

Bensam123 wrote:These were brand new, it's hard to imagine only the Seasonic connectors would get dirty (by me)and only on certain cards. The other PSUs should be exhibiting similar signs. That leaves factory issued dirt?

Yeah, either Seasonic's, or one of their suppliers. Could've been as simple as a batch of connector pins that had dodgy plating on them, or that were exposed to water for an extended period of time before they got used.

Bensam123 wrote:It's a possibility that the R9-290s were drawing too much current. But in one case it was on my gaming PC, on the other two it was a R9-290 with two cables hooked up to it and a 7970. Those were mining pretty much 24/7, but I undervolt my cards, so it's hard to imagine these drawing more wattage then what you see in stress tests normally for the card.

Well, if it really was a high-resistance hot spot, it could take a while for things to get bad enough to cause visible damage. Long enough to pass a stress test.

All of the above aside, I think I've just thought of another failure scenario, which is probably more likely than any of the ones I listed before: A bad crimp inside the cable connector housing where the pin is attached to the wire. If the crimp is loose, you'll get a hot spot and maybe even some arcing inside the connector. This will cause the surface of the copper wire to oxidize, quickly leading to the positive feedback / thermal runaway scenario described in my previous post.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 11:10 am

Bensam123 wrote:Each connector is rated for 150w, yet they're what melted. None of the cables are stated that they're limited to 150w a piece (they also did not melt). If they were limited to 150w per cable they would be sending you cables that are 6+2 not 2x6+2 and adding warnings or information for such configurations. I checked the manual for what that's worth after noticing this and looked around a bit and saw no such warnings or load ratings.

http://www.seasonicusa.com/images/Broch ... Manual.pdf


IIRC, the X series comes with PCI cables that have 8 pin on the PSU end and 6 pin + 6+2 pin on the other end. Am I correct on this?

If so, the cable is rated only for 150W. So if you plug in the 8Pin side into the PSU and plug in the 6 pin into your GPU's 6pin and the 6+2 pin onto your GPU's 8pin, you are definitely going to have a burnt cable on the PSU end.

The reason why they ship with 6+2 and 6 pin on the GPU end is so that you can satisfy either of the two scenarios:

1. Your GPU has 2x6 pin connectors. In this case, you use a single cable for both connectors. Each 6 pin connector is rated for 75 watts. There are two connectors on the GPU side. Each 8 pin is rated for 150W. So the math all adds up.

2. Your GPU has one 6 pin and one 8 pin or two 8 pin connectors. In this case you must use two cables. Connect the 6+2 pin GPU end of the cable into the 8 pin and the 8 pin PSU end into the PSU. Using a second cable, connect the other GPU connector to the PSU. Total GPU wattage = 225W-300W. Total Cable rated wattage = 300W. So the math all adds up.

I suspect what you did was to power the 290 with a single cable. This is an absolute no-no. If your cables melted, be happy that it didn't burn down the house.
LASR
Gerbil
 
Posts: 70
Joined: Fri Jan 10, 2014 9:35 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 11:19 am

LASR wrote:If so, the cable is rated only for 150W. So if you plug in the 8Pin side into the PSU and plug in the 6 pin into your GPU's 6pin and the 6+2 pin onto your GPU's 8pin, you are definitely going to have a burnt cable on the PSU end.

Why only on the PSU end? Same number of same gauge pins carrying the same amount of current at the GPU end.

(But I do agree that if he indeed exceeded the ratings of the cables, that's really just a side issue... *something* was gonna burn regardless!)
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 11:43 am

just brew it! wrote:
LASR wrote:If so, the cable is rated only for 150W. So if you plug in the 8Pin side into the PSU and plug in the 6 pin into your GPU's 6pin and the 6+2 pin onto your GPU's 8pin, you are definitely going to have a burnt cable on the PSU end.

Why only on the PSU end? Same number of same gauge pins carrying the same amount of current at the GPU end.


Because there is more than 150w being carried through the PSU end. On the GPU end you would have the 6pin connector and the 8pin connector sharing the load. So neither of the two connectors carries more that 150w

So you have 6 pins per polarity on the GPU side, compared to only 3 pins per polarity on the PSU side.
LASR
Gerbil
 
Posts: 70
Joined: Fri Jan 10, 2014 9:35 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 11:55 am

LASR wrote:
just brew it! wrote:
LASR wrote:If so, the cable is rated only for 150W. So if you plug in the 8Pin side into the PSU and plug in the 6 pin into your GPU's 6pin and the 6+2 pin onto your GPU's 8pin, you are definitely going to have a burnt cable on the PSU end.

Why only on the PSU end? Same number of same gauge pins carrying the same amount of current at the GPU end.


Because there is more than 150w being carried through the PSU end. On the GPU end you would have the 6pin connector and the 8pin connector sharing the load. So neither of the two connectors carries more that 150w

So you have 6 pins per polarity on the GPU side, compared to only 3 pins per polarity on the PSU side.

Ahh, OK. I misunderstood what you were getting at. Guess we just need the OP to confirm (or refute) that this is how things were hooked up.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 1:19 pm

maxxcool wrote:Never have trusted seasonic.. mostly stick to cosair, evga, enermax psu's with single rail 12v lines and giant caps inside.


Much of Corsair's PSU lineup are SeaSonic PSUs. Likewise, EVGA units typically come from FSP or Enhance. Of the 3 you listed, only Enermax is both a label and manufacturer.
slowriot
Gerbil First Class
Gold subscriber
 
 
Posts: 165
Joined: Wed Apr 03, 2013 10:57 am

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 5:14 pm

LASR wrote:
Bensam123 wrote:Each connector is rated for 150w, yet they're what melted. None of the cables are stated that they're limited to 150w a piece (they also did not melt). If they were limited to 150w per cable they would be sending you cables that are 6+2 not 2x6+2 and adding warnings or information for such configurations. I checked the manual for what that's worth after noticing this and looked around a bit and saw no such warnings or load ratings.

http://www.seasonicusa.com/images/Broch ... Manual.pdf


IIRC, the X series comes with PCI cables that have 8 pin on the PSU end and 6 pin + 6+2 pin on the other end. Am I correct on this?

If so, the cable is rated only for 150W. So if you plug in the 8Pin side into the PSU and plug in the 6 pin into your GPU's 6pin and the 6+2 pin onto your GPU's 8pin, you are definitely going to have a burnt cable on the PSU end.

The reason why they ship with 6+2 and 6 pin on the GPU end is so that you can satisfy either of the two scenarios:

1. Your GPU has 2x6 pin connectors. In this case, you use a single cable for both connectors. Each 6 pin connector is rated for 75 watts. There are two connectors on the GPU side. Each 8 pin is rated for 150W. So the math all adds up.

2. Your GPU has one 6 pin and one 8 pin or two 8 pin connectors. In this case you must use two cables. Connect the 6+2 pin GPU end of the cable into the 8 pin and the 8 pin PSU end into the PSU. Using a second cable, connect the other GPU connector to the PSU. Total GPU wattage = 225W-300W. Total Cable rated wattage = 300W. So the math all adds up.

I suspect what you did was to power the 290 with a single cable. This is an absolute no-no. If your cables melted, be happy that it didn't burn down the house.



I've actually seen this with hardware we manufacture in house, using connectors that are being run completely within spec. The problem isn't power so much as it is current. The connectors oxidize, have dirt, are loose, or otherwise show a higher resistance. One pin, especially a ground pin is enough to start the cascade. The slight increase in resistance drops the voltage a little bit across the connector. Because the load on the other side uses a switching regulator to do load point power regulation, the drop in supply voltage causes the the regulator to draw slightly higher current. The power dissipated in the connector is P=(I^2)R so the power (heat) dissipated by the connector rises as the square of the current increase. Even a half an ohm at the connector is enough to melt it. It's a pretty nasty cascade too. We would see one ground pin go bad and eventual fail open or high (>1 ohm) resistance effectively running the entire load through less connectors, causing them to fail. It was enough to let the magic smoke out.

Image

If you were running >200W though a 150W rated connector for extended periods, then the fact that it just melted the housing together is actually pretty good.

Note: Not a Seasonic fan and the fact the you were running past spec doesn't mean that Seasonic wasn't using cheaper parts. However, unless otherwise proven, I would expect those cheaper parts to perform admirably when run within their specified ratings.

--SS
SecretSquirrel
Gerbil Jedi
Gold subscriber
 
 
Posts: 1738
Joined: Tue Jan 01, 2002 7:00 pm
Location: The Colony, TX (Dallas suburb)

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 10:40 pm

This could very well be a hot spot with dirt or a loose connection. The connectors were definitely snug, obviously this does not mean the pins were snugly attached to each other though. It could also be the R9-290s draw more power through certain pins as someone else mentioned as well, but this also happened on a 7970 too. As I mentioned earlier other 7970s/R9-280xs are hooked up with a single cable and they aren't showing any signs of breaking down or hot spots.

The big deal here is that the connectors on the GPUs are perfectly fine. If the female plugs on the PSU are melting and the male ends on the cables are melting, the GPU plugs should also be melting... As long as they're all up to the same specs. The same goes for the other scenarios where the receptacle doesn't melt, but the plugs melt (there were 24 pin plugs and EPS plugs showing similar things in other posts).

LASR wrote:IIRC, the X series comes with PCI cables that have 8 pin on the PSU end and 6 pin + 6+2 pin on the other end. Am I correct on this?

If so, the cable is rated only for 150W. So if you plug in the 8Pin side into the PSU and plug in the 6 pin into your GPU's 6pin and the 6+2 pin onto your GPU's 8pin, you are definitely going to have a burnt cable on the PSU end.

The reason why they ship with 6+2 and 6 pin on the GPU end is so that you can satisfy either of the two scenarios:

1. Your GPU has 2x6 pin connectors. In this case, you use a single cable for both connectors. Each 6 pin connector is rated for 75 watts. There are two connectors on the GPU side. Each 8 pin is rated for 150W. So the math all adds up.

2. Your GPU has one 6 pin and one 8 pin or two 8 pin connectors. In this case you must use two cables. Connect the 6+2 pin GPU end of the cable into the 8 pin and the 8 pin PSU end into the PSU. Using a second cable, connect the other GPU connector to the PSU. Total GPU wattage = 225W-300W. Total Cable rated wattage = 300W. So the math all adds up.

I suspect what you did was to power the 290 with a single cable. This is an absolute no-no. If your cables melted, be happy that it didn't burn down the house.


It didn't just happen on the PSU end, it happened on the GPU end as well, including a double cable hookup (this can be seen in the pictures). Two cables were run to one R9-290 and that had the same issue on one of the cables connecting to the plug on the card itself. The R9-290 in my main gaming PC was powered with a single connector, yes. There was nothing stating that you can't do that. The plugs are rated for 150w on the ends (the only reason I know this is based on the standard, not what Seasonic has in their literature). What Seasonic does with the other end of the plug is up to them and I assume they'd take into account what happens on the double plug end.

Graphics cards are designed with connectors for the amount of wattage they need. It's not arbitrary. They add a extra plug when it needs extra wattage. There isn't a case where you have a 150w graphics card with two 8 pin connectors on it or even 2x6. You wouldn't design a cable with two 8 pin connectors on it if you know it can't handle the wattage those connectors are designed around and the whole system is based around.

Each 8 pin connector is rated for 150w, not 75w. The GPU has 8 pin connectors on it. I assume the jackets are made to support the heat levels associated with 150w and that's what we're working on here. The connectors melted, not the cables or the pins.

Please read the whole post before chastising me for almost burning my house down... that seems to be a common trend happening here. :l
Bensam123
Gerbil Elite
 
Posts: 952
Joined: Wed May 29, 2002 12:19 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Tue Jul 15, 2014 11:41 pm

I think what he was getting at was that if you have a Y cable (2 8-pin connectors at the GPU end but a single 8-pin connector at the PSU end), and you're drawing close to the maximum 150W from each connector at the GPU end, then you're drawing around 300W through the connector at the PSU end, and this likely exceeds the ratings of the contacts.

Edit: I think it's all kind of moot anyway. The standard PCIe power connectors are from Molex's "Mini-Fit Jr" family or equivalent; the contacts are supposed to be rated for 9A each. So on an 8-pin PCIe connector, where 4 pins are the +12V and 4 are the return, you've got 4 parallel circuits, for a total current carrying capacity of 36A. For a 12V supply, that's 432W!

Given this, I'm really leaning towards dirty contacts or bad crimps. I find it pretty far-fetched that the specs of the connectors are being exceeded.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Fri Jul 18, 2014 1:10 am

Yeah I'm pretty sure it's faulty crimps. Based on the melt patterns it would seem as though they were getting hotter then usual in a few spots. The pins didn't melt down evenly, the plastic melted down only around one or a few pins on some, where as on other connectors they melted somewhat uniformly. The combined hotter temperatures of the R9-290 is probably adding to this (the whole card gets pretty toasty under load). I am using a first gen R9-290s as well, not one with a third party coolers. I haven't dissected the cords further as I wanted to talk to Seasonic first. This seems like it may be wide spread across Seasonics though based on what's happening.

I do agree that it would be drawing 300w on the PSU end, I believe Seasonic would account for that by attaching two 150w connectors to one cable though.
Bensam123
Gerbil Elite
 
Posts: 952
Joined: Wed May 29, 2002 12:19 pm

Re: Mining with Seasonic Power Supplies!

Postposted on Fri Jul 18, 2014 6:21 am

I can't say for mining, but I can say for folding.

I've been folding constantly with two Radeon 6970s in Crossfire, a Core i7-2600K clocked to 4.2GHz (stock temperatures, cooled with a Thermalright TRUE Black and two 120mms in push/pull) and I've used a Seasonic X750 Gold that whole time.

Not one issue.

I just upgraded the video cards to two XFX Double-Dissipation Black Edition R9 280x last night. So far, even better. GPU temps are down a bit due to the lower die process, and Graphics Core Next is built for GPGPU, improving scores The cards are reasonably quiet even under load.

I've had my Seasonic now for probably four years. It has been rock solid for the rig in my sig. About the only unit I'd trade it for is the X850 (or is it X860) for just a little more cushion.
Core i7-4790K, GIGABYTE Z97X-UD5H-BK, 16GB (4x4) G.Skill RipJaws PC1866
Corsair 650D case, Seasonic X750 Gold PSU
WD `Raptor 600GB boot, WD Caviar Black 1TB data, NEC 7200 DVDRW
ASUS STRIX GTX 970, X-Fi Titanium, Dell 2408WFP
LoneWolf15
Gerbil XP
Silver subscriber
 
 
Posts: 471
Joined: Tue Feb 17, 2004 8:36 am
Location: SW Meecheegan

Re: Mining with Seasonic Power Supplies!

Postposted on Wed Dec 03, 2014 6:47 am

just brew it! wrote:So on an 8-pin PCIe connector, where 4 pins are the +12V

3 pins... ;)
XTF
Gerbil
 
Posts: 23
Joined: Sun Sep 11, 2011 11:55 am

Re: Mining with Seasonic Power Supplies!

Postposted on Wed Dec 03, 2014 6:51 am

Bensam123 wrote:Graphics cards are designed with connectors for the amount of wattage they need. It's not arbitrary. They add a extra plug when it needs extra wattage.

Why do cards have 2x 6 instead of 1x 8 though? It's kinda problematic.

Bensam123 wrote:...

What did Seasonic say? You did contact them, didn't you?
XTF
Gerbil
 
Posts: 23
Joined: Sun Sep 11, 2011 11:55 am

Re: Mining with Seasonic Power Supplies!

Postposted on Wed Dec 03, 2014 7:08 am

XTF wrote:
Bensam123 wrote:Graphics cards are designed with connectors for the amount of wattage they need. It's not arbitrary. They add a extra plug when it needs extra wattage.

Why do cards have 2x 6 instead of 1x 8 though? It's kinda problematic.

They probably didn't want to occupy half of the card edge with the connector.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Wed Dec 03, 2014 8:57 am

just brew it! wrote:
XTF wrote:
Bensam123 wrote:Graphics cards are designed with connectors for the amount of wattage they need. It's not arbitrary. They add a extra plug when it needs extra wattage.

Why do cards have 2x 6 instead of 1x 8 though? It's kinda problematic.

They probably didn't want to occupy half of the card edge with the connector.

What? 1x 8 takes up less space then 2x 6.
XTF
Gerbil
 
Posts: 23
Joined: Sun Sep 11, 2011 11:55 am

Re: Mining with Seasonic Power Supplies!

Postposted on Wed Dec 03, 2014 9:16 am

XTF wrote:Why do cards have 2x 6 instead of 1x 8 though? It's kinda problematic.

Because older PSUs (and a lot of recent ones) only have 6-pin PCIe plugs.
There is a fixed amount of intelligence on the planet, and the population keeps growing :(
morphine
Grand Admiral Gerbil
Silver subscriber
 
 
Posts: 10092
Joined: Fri Dec 27, 2002 8:51 pm
Location: Portugal (that's next to Spain)

Re: Mining with Seasonic Power Supplies!

Postposted on Thu Dec 04, 2014 6:52 am

XTF wrote:
just brew it! wrote:They probably didn't want to occupy half of the card edge with the connector.

What? 1x 8 takes up less space then 2x 6.

Takes up more space along the edge of the board because it is longer. You'll also have a long, skinny PSU connector that is 2/3 the length of the main ATX motherboard connector.
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: Mining with Seasonic Power Supplies!

Postposted on Thu Dec 04, 2014 9:24 am

just brew it! wrote:
XTF wrote:
just brew it! wrote:They probably didn't want to occupy half of the card edge with the connector.

What? 1x 8 takes up less space then 2x 6.

Takes up more space along the edge of the board because it is longer. You'll also have a long, skinny PSU connector that is 2/3 the length of the main ATX motherboard connector.

What is longer? One 8p connector is NOT longer than two 6p connectors is it?
XTF
Gerbil
 
Posts: 23
Joined: Sun Sep 11, 2011 11:55 am

Re: Mining with Seasonic Power Supplies!

Postposted on Thu Dec 04, 2014 8:51 pm

Ahh, I think I see where we're getting confused. When you said 1x8 I thought you meant that there should be a new type of connector with a single row of 8 pins. Never mind...
(this space intentionally left blank)
just brew it!
Administrator
Gold subscriber
 
 
Posts: 38125
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Next

Return to Cases and Power Supplies

Who is online

Users browsing this forum: No registered users and 1 guest