Personal computing discussed
Moderators: renee, SpotTheCat, Nemesis
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...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
Were you able to check the PSU side of the connectors as well?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.
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.
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.
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.
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?
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.
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
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.
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.
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.
maxxcool wrote:Never have trusted seasonic.. mostly stick to cosair, evga, enermax psu's with single rail 12v lines and giant caps inside.
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.
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.
just brew it! wrote:So on an 8-pin PCIe connector, where 4 pins are the +12V
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.
Bensam123 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.
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.
XTF wrote:Why do cards have 2x 6 instead of 1x 8 though? It's kinda problematic.
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.
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.