8800GTX SLI Problems - PSU related?

harmattan

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Jul 24, 2006
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Question: what occurs in 3D when one SLI card is not getting enough power (what happens on the screen)? Would I get artifacts, crashing, an error or all of the above?

After being able to run for a couple of hours, I'm now seeing major artifacting (screen-size black triangles/streaks). I'm wondering if maybe it's due to one of my PSU's 12v rails not running. I'm also getting crackling from my PSU, but I was getting that when my sys was running correctly too and have heard it's common with TT models.

e6600 (3.2ghz)
2GB Corsair 6400
2XWD 160 GB SATA RAID 0
2xeVGA 8800gtx sli
Thermaltake Toughpower 850W
 

Heyyou27

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That PSU should be good enough; what have your GPU temperatures been like? Have you emailed eVGA? Try removing one of your cards and running it alone to see if artifacts persist; if not, swap out the first card for the second one and test again. If no problems occur when running a single card, I'd say it's safe to assume your power supply is the problem.
 

harmattan

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That PSU should be good enough; what have your GPU temperatures been like? Have you emailed eVGA? Try removing one of your cards and running it alone to see if artifacts persist; if not, swap out the first card for the second one and test again. If no problems occur when running a single card, I'd say it's safe to assume your power supply is the problem.

Yeah, thought of testing the cards, but wanted to know if this could possibly be a PSU issue before I start. Unfortunately, I'm out of town for the weekend and won't be able to check until Mon.

Temps on one of my GPUs is rather high. Idles around 81c, and levels off at 85c during load (the other idles at 72/82load). Airflow in my case is excellent and I've even tried to align an extra fan blowing directly on the hot GPU to no avail.
 

waylander

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If those are your temps then I think you've found the problem. You've got a dual core cpu and 4... 4!!! gpu's running in your case.

What kind of case do you have and when you say excellent air flow... wtf does that mean? Do you have 2 fans? 4 fans? 8 fans? are they 80mm? 92mm? 120mm? 30cfm? 50cfm? 100cfm?

Fans in front, behind, sides, top, bottom...
 

harmattan

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If those are your temps then I think you've found the problem. You've got a dual core cpu and 4... 4!!! gpu's running in your case.

What kind of case do you have and when you say excellent air flow... wtf does that mean? Do you have 2 fans? 4 fans? 8 fans? are they 80mm? 92mm? 120mm? 30cfm? 50cfm? 100cfm?

Fans in front, behind, sides, top, bottom...

TT Armor. 6 fans total. 1 120mm front, 1 120mm back, 1 120mm CPU (Scythe INF) pushing air back, 1 90 mm top, another 90mm next to PSU. I've also aligned another 90mm between my HDD's and bottom (hot) 8800 pushing air back. I've tried with and without the side panel, but it doesn't affect temps much.

All other temps in my sys are good (CPU 44c idle/52c load, MPU 66c load). I've narrowed it down to one of my 8800's - it's going back to eVGA tommorow.