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DPete27
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GPU 6-Pin Power Orientation

Tue Sep 09, 2014 1:09 pm

I built a used system for a co-worker that's been nothing but problems from day one. ($200 hardware budget for a gaming tower+monitor) My co-worker recently notified me that the computer is not posting again (I replaced the mobo earlier thinking that was the source of the problem, worked fine for about a month and a half).

Core 2 Duo E8400
4GB RAM
Gigabyte EP43-UD3L mobo
Corsair CX430 PSU
XFX 5830 GPU

So this time, I thought the Corsair CX430 PSU had taken a dump already (happened to a friend, less than 1 year after purchase). I swapped in a new PSU...nothing. Cleared the CMOS, it worked. Did a few things, didn't work again. Sporadic, behavior (great) but the new PSU definitely didn't fix the problem.

Next I tried updating the BIOS in the Gigabyte board. I got it on ebay from a reputable seller, looked brand new, but had the latest BIOS so I figured maybe they didn't flash the BIOS for the proper mobo revision (Rev. 1.0). That seemed to fix the problem! Unplugged and re-plugged things, moved the tower, set the tower back up, many restarts/power cycles/etc and not a hitch. Awesome! Gave the computer back.

2 days later...same problem. Ugh. Only idea I have left is that the XFX 5830 is causing the problem. The CX430 only has a single 6-pin PCIe power connector and the 5830 requires two. I installed a molex-6pin adapter for the second plug, but is there a specific orientation that the "native" 6-pin from the PSU and 6-pin adapter should be mounted? I can't imagine it should matter, but I'm fresh out of ideas.

My last option is to swap out the GPU. I have a GT630 laying around that I could donate, but that's going to be a significant step down in terms of graphics performance for her 13 year-old son to play games with. I actually ended up swapping the GT630 in to get the computer to post so I could flash the BIOS. Again though, with the sporadic behavior, I can't be certain at this time if it was a fluke or if the GT630 was the solution.
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Darthutos
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Re: GPU 6-Pin Power Orientation

Tue Sep 09, 2014 1:19 pm

The CX430 only has a single 6-pin PCIe power connector and the 5830 requires two. I installed a molex-6pin adapter for the second plug,


You should either find a PSU that has 2 6 pin adapters, or a GPU that has only 1 6 pin slot. Never trust a molex adapter.
Edit: I know most 2 6 pin adapter PSU are almost always 2 or more 6/8 adapters, and the wattages are 750W +, but what can you do?

As for orientation, you look at the slot on the gpu, it's keyed so that one side of the surface has a indentation. Look at your cable from the PSU, one side is smooth and the other is not....
put the two non smooth sides together.
another way to find orientation is look at the gpu, which side has the fan? put the non smooth psu cable on that side.
 
DPete27
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Re: GPU 6-Pin Power Orientation

Tue Sep 09, 2014 2:45 pm

Darthutos wrote:
As for orientation, you look at the slot on the gpu, it's keyed so that one side of the surface has a indentation. Look at your cable from the PSU, one side is smooth and the other is not....

It was more a question of: does it matter if the 6-pin cable from the PSU is in the plug nearest the mobo (say plug #1) and the 6-pin adapter in plug #2 or vice versa?

Darthutos wrote:
Never trust a molex adapter.

Seriously? Why would they make 6-pin adapters if they weren't reliable?
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
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credible
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Re: GPU 6-Pin Power Orientation

Tue Sep 09, 2014 3:46 pm

Afraid I won't be much help but I did come to post something odd and I saw your thread so I'll respond here because it is relevant.

I have a 660 ti and my youngest son has a hd 6850 toxic 1gb card, he also has the same PSU that you are using for that rig, both cards required 2 6 pins and both have worked perfectly fine in his tower, he has a fx-6100 and an ssd and a mechanical drive, as well as a cd/dvd drive, plus the motherboard of course,lol.


Now the interesting thing is this, I am not playing any games presently so I loaned him my 660 ti and I am using the hd 6850 and believe it or not as soon as I rebooted after installing the new drivers my web pages are loading noticeably quicker, kind of odd I think but I am not complaining.
 
Darthutos
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Re: GPU 6-Pin Power Orientation

Tue Sep 09, 2014 4:02 pm

Seriously? Why would they make 6-pin adapters if they weren't reliable?


Just read all the reviews on newegg or other e-tailers. Look at the 1 egg or 1 star reviews.
Almost all of them involve burned peripherals with molex adapters. including gpu and sata.

People make unreliable items all the time. It has something to do with $s.
 
credible
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Re: GPU 6-Pin Power Orientation

Tue Sep 09, 2014 4:08 pm

It may also have something to do with the PSU's they are using, could have been cheap ones, just a thought.
 
Chrispy_
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Re: GPU 6-Pin Power Orientation

Wed Sep 10, 2014 5:53 am

CX430 can't really power anything more than a 150W graphics card.
It's Corsair's lowest-quality PSU and I've found an Antec Greenpower 380W supply capable of booting with hungrier graphics cards (170W 560Ti) than the CX430.

If it doesn't have the connectors, it's because the rail isn't reliably capable of providing that much juice.
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DPete27
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Re: GPU 6-Pin Power Orientation

Wed Sep 10, 2014 8:34 am

Chrispy_ wrote:
If it doesn't have the connectors, it's because the rail isn't reliably capable of providing that much juice.

A CS450M (80 Plus Gold, modular) wasn't able to get it going (reliably) either. I say "reliably" because, as stated above, the blasted thing worked fine for me with the CX430 reinstalled almost a dozen times before I gave it back. The CX430 can do 380W off the 12V rail and the CS450 can do 425W...Do you really think this setup is pulling that much juice on startup that it's teetering on the edge of instability? I did some stress testing to check temps when I initially built the system and didn't come across any crashes. TR has system draw at 262W with an i7-965.

I'd hate to do this, but I might try pulling the PSU from my gaming rig that has 2 6-pin connectors and see if that works......ugh, that means I'd have to fish all the neatly routed wires out, and then re-route/install them... What a pain.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
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Chrispy_
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Re: GPU 6-Pin Power Orientation

Wed Sep 10, 2014 10:01 am

Some graphics cards refuse to boot unless all aux power connectors are connected and at the right voltages.

If you're using a Molex adapter even with the CS450, check that it's only using black (GND) and yellow (+12V) wires. I've seen 2x4pin-to-1x6pin cables that use the red +5V line before. They came with an HIS card, I believe.
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Kougar
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Re: GPU 6-Pin Power Orientation

Wed Sep 10, 2014 8:30 pm

In the old days (relative term I know) PSUs expected GPUs to use molex connectors, but not anymore. If a modern PSU doesn't have a GPU power connector then it simply wasn't intended (and probably not designed) to support a GPU that draws that much power. The intermittency of the problem makes it sound like a power issue, so I'd be curious if upgrading to a PSU with an actual PCIe power connector might fix it.

Yes, 6-pin GPU / PCIe power plugs are polarized. One side has 3 yellow (12v lines) and the other side has 3 black (Ground). Link When you use an adapter the single yellow line on a molex plug is feeding 3 yellow 12v lines into the GPU, basically. It's keyed to install only one direction, installing it the wrong way would be a short to ground and would fry something if the PSU's safeties don't kick in first.

EDIT: I just looked at that specific GPU and it requires TWO PCIe power connectors. You should never use such a power hungry GPU with a PSU that doesn't have any, you're overloading the PSU's molex rails. :o I bet you would've fried something except the safeties are kicking in. Probably why it has trouble starting too from the required start-up surge the system needs.
 
DPete27
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 8:24 am

I assumed that since 4-pin Molex is a 12V feed and both PSUs are single 12V rail units that hooking up a Molex - PCIe adapter wouldn't be a problem.

As it stands, I ordered another PCIe adapter (just in case the first one is somehow defective that I cant detect. Hey, it was $2). I'm going to try that, and if it doesn't work I'm going to opt for the GPU swap (GT630) instead of yanking the PSU from my own gaming rig. I've put countless hours into this machine already and haven't received a penny for my labor. I think she just wants a working system, whereas I have her son's gaming interests in mind and didn't want to give him a card with half the performance, but he'll have to deal. Maybe he can get mom to pony up for a new GPU for Christmas or something. At his age, he's right on the cusp of choosing sides between console and PC gaming. Surely a GT630 will not help persuade him...I fear we'll lose another to the dark side.

*I need to find a "customer" willing to pay the cost of a decent system. I've had to build far to many sub-budget systems lately and it's destroying my will to live.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
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phil42
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 9:26 am

would you please try something for me? please try an entirely separate 12 volt supply, even a battery would do.
i have a 12volt hungry card and i worry that my supply will pop. i want to know if a separate 12volt supply will work.
 
DPete27
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 9:51 am

phil42 wrote:
please try an entirely separate 12 volt supply

While that thought had crossed my mind, the only hesitation I have with paper-clipping in a second PSU is that the current sporadic behavior might make it difficult for me to draw a reliable conclusion (I'd much rather have it consistently NOT work, at least then it would be easier to nail down the problem). Like I said, the CX430 setup worked fine for me 8-12 times in a row over the course of 2-3 days of testing. Worked at my co-workers' house for a day, then on day 2, nothing. Heck, previous to this, it worked just fine for almost 2 months.
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Darthutos
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 1:58 pm

I am speechless.
2 dollar pci-e adapter. How much you want to bet that it'll work for another 12 months, and then one day it won't work anymore... :evil:
 
credible
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 2:03 pm

*I need to find a "customer" willing to pay the cost of a decent system. I've had to build far to many sub-budget systems lately and it's destroying my will to live."

That is too damn funny as I have been having that same issue, can you save us as much money as possible,lol.


Do keep in mind that I mentioned the 2 different 6 pin cards that I have been using with the same PSU, perhaps there is an issue with the power outlet that they are plugging the system into at the house, just a thought.
 
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 3:58 pm

credible wrote:
*I need to find a "customer" willing to pay the cost of a decent system. I've had to build far to many sub-budget systems lately and it's destroying my will to live."

That is too damn funny as I have been having that same issue, can you save us as much money as possible,lol.


Do keep in mind that I mentioned the 2 different 6 pin cards that I have been using with the same PSU, perhaps there is an issue with the power outlet that they are plugging the system into at the house, just a thought.


Just stop charging a fixed fee and start charging by the hour.
Nasty slow computers eat your soul. If someone is after a nasty slow computer, tell them to buy the cheapest thing in Wallmart and enjoy their nasty slow computer, it's not worth your time and as you get older you realise that the value of your free time increases for every minute of doing something you're not enjoying.

Currently my free time is priceless, because I'm stuck at work "on call" reading the interwebs.
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DPete27
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 4:30 pm

Chrispy_ wrote:
Just stop charging a fixed fee and start charging by the hour. Nasty slow computers eat your soul.... not worth your time

Unfortunately building computers is something I very much enjoy, but I don't have a "customer base" (just family/friends) so all I ask is that they pay for the hardware, and my labor compensation is being able to do what I enjoy. I always accept free-will donations above and beyond the hardware cost, but I fear if I charged for my time, I wouldn't be building any computers except my own. (my wife would kill me if I built myself 2 computers/year)

This approach has worked well for me in the past. I don't even mind minimal/infrequent customer service tasks, but every so often a devil spawn (like this computer) comes along and makes me question why I put myself in these situations. Admittedly, this is far and above the worst behaving build I've ever done.

Even though this molex to 6-pin PCIe adapter situation doesn't make 100% sense to me, I'll definitely make a conscious effort in the future to select a PSU with two 6-pin PCIe connectors if the GPU requires them. Leave nothing to chance.
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Kougar
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 8:12 pm

DPete27 wrote:
I assumed that since 4-pin Molex is a 12V feed and both PSUs are single 12V rail units that hooking up a Molex - PCIe adapter wouldn't be a problem.


Okay, I didn't realize the PSU has one PCIe connector and you're using a second molex adapter ontop of that. Regardless the PSU has a 12 volt max load rating of 384w, and you're close to that limit. Factor in the start up surge and you're probably exceeding it, which is why the system has trouble POSTing properly, the safeties are going to prevent you from exceeding the unit's limit even if it's just the brief surge to get the hard drives and fans spinning up.

You always have to factor in the startup surge, not just sustained power under load.
 
k00k
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Re: GPU 6-Pin Power Orientation

Thu Sep 11, 2014 9:21 pm

Well, I've used molex to 6-pin adapters in the past, the most recent one was for a Sapphire 6950, since my PSU at that time did not have dual graphics connectors. There was one in the card's box, so I thought to myself, "might as well use that for now and save for a new build." This was for a Phenom II machine then.

First try didn't boot. The Molex adapter was initially connected to a line that had several fans on it already. The other 12v line was for the HDD, and was paranoid about putting anything else on there for fear of adding jitters to the HDD's power. I figured trying it on the least "busy"/loaded line would be safest, and that was the floppy line, which only had a DVDRW. Putting the Molex-PCIE GFX on that line worked.

Perhaps you could try something like that? (Though that rig was fairly light, one HDD, two 12cm fans, a 7cm fan for the Zalman HSF, a quad-core Phenom and a Gigabyte mATX board, 4GB of RAM, an X-Fi, and a DVDRW.) YMMV
 
DPete27
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Re: GPU 6-Pin Power Orientation

Fri Sep 12, 2014 10:17 am

Kougar wrote:
Regardless the PSU has a 12 volt max load rating of 384w, and you're close to that limit. Factor in the start up surge and you're probably exceeding it

The 5830 has a TDP of 175W, E8400 = 65W, 1 hard drive at ~8W, and 2 fans creates a startup surge of over 384W? That's an interesting phenomenon. I'll have to do some research into that.

It definitely seems like we've come to some sort of group consensus that a GPU that requires dual 6/8 pin PCIe power should be accompanied by a PSU with the "proper" cabling and that molex-to-PCIe adapters are just snake oil trickery. At any rate, I'm going to test this weekend with Prime95 and Furmark running at the same time (I wish I had a kill-a-watt meter) which should create the maximum possible system load and see if I get instability. I can't remember if I ran both power viruses at the same time when I was stability testing the initial build. I'll post back in a few days with my results, by that time I should have taken delivery of the replacement 6-pin adapter to also test if the current adapter is faulty.

**Note, I haven't experienced system instability/crashes from this system during any of my time with it once it was booted into windows (stress testing or software updates/installs), only during startup/post**

Again, I just wish I could get some kind of consistent behavior from the thing to aid my troubleshooting. Not this: boot up properly 5 times in a row and the 6th time...nothing.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
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Kougar
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Re: GPU 6-Pin Power Orientation

Fri Sep 12, 2014 3:52 pm

Again, max sustained load and startup surge are not the same thing. I doubt the sustained load will exceed the PSU's ratings, but the startup surge is probably too high for the PSU rating hence your startup problems.

Anandtech tested it with a stock i7 920 and SSD, and the 5830 open-air system pulled 332 watts under load, no drives or case fans.
 
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Re: GPU 6-Pin Power Orientation

Sun Sep 14, 2014 5:50 am

Again, I just wish I could get some kind of consistent behavior from the thing to aid my troubleshooting. Not this: boot up properly 5 times in a row and the 6th time...nothing.


It's anecdotal rather than scientific, but in my almost 20 years of experience, inconsistency is very frequently power dependent - whether it's a slightly loose connection, a faulty PSU or a capacitor that isn't discharging properly.

Don't rule out the possibility that the PSU is close to the limit of what it can provide and on "dirty power" exhibits instability - is their house running old electrical wiring, is there a lot of noise on their ring-mains circuit, are they using an old surge-protected extension cable where the little neon light is flickering erratically? I've seen completely stable builds flake out when connected to a different outlet before in an old building where one of the circuits was below spec - A UPS plugged into that circuit complained of poor supply and some further testing revealed that the 240V mains supply oscillated between 210 and 235V quite sparodically.
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credible
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Re: GPU 6-Pin Power Orientation

Sun Sep 14, 2014 9:53 am

Precisely what I was thinking as well Chrispy, its the only other logical place to look after you have confirmed everything is good with the puter.

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