2nd 8800 GTS problem in SLI.

[torin3]

Ok, I've got the system in my signature. I just got in my second 8800GTS and I figured I would test it out. Swapped it out for the current one and ran 3DMark06 on it. No problem, other than I forgot to reset the defaults on bootup for RivaTuner. It locked up. Ok, probably not as good of an overclocker, but I'll deal. Get them set properly for defaults and run again. Almost identical score to what I got for my first card.

All going according to plan so far.

Put the original back in as well, plug on the SLI connector and turn it on in the bios.

Enable SLI.

Run 3DMark06. Whoo-hoo, a 15 FPS gain at the start...but wait a minute! My system just shut down! Right when the FPS would drop from heavier load.

Ok. Reboot and do a clean reboot. Run again.

Crashes in the exact same spot.

Reboot and clean reboot, and turn the settings down to 450/700. Run 3DMark06 again. Turns off again.

CRUD!!!



Ok, I enabled hardware monitoring on the last run and it appears that the temp was actually going down right before the crash. Ok, not an overheating issue. Temps were 52C and 47C before the crash.

Any idea what could be wrong? I can get another PSU if it isn't holding up.

I've got all 3 power points on the motherboard connected and the PCI-E 6pin plugs connected to the cards!

Just to double check, I pull the 2nd card out and run 3DMark06 again. No crash with a single card.

HELP!!

 

[goodgod]

Looks like a psu problem... 600w isnt that big for a pair of 8800 gts... I recommend something like a silverstone zeus 750w or any other nice brand psu, 700w+

 

[rdrash]

I think goodgod is correct.....probably a PSU issue, maybe the amp draw is too great on the 12V line or the total Wattage being drawn exceeds what your PSU can handle.

 

[torin3]

I was afraid that might be it.

Also, I do have a UPS on the line. It is only powering the computer and my waterpump. It isn't that beefy, and I mainly have it on so that the water pump is always on when the computer is, and so that the power is somewhat conditioned. Is it possible that this is limiting the power available to the PSU?

 

[Hipcrostino]

If UPS's can't handle the draw they suppliment it with direct mains power and tell you about it. Just take it out of the system for a moment and check if it is, but yeah it sounds very much like a PSU problem. Your on the ragged edge i would say if it starts the bench marks but fails in high action.

 

[torin3]

Well, I'm going to be placing an order in an hour or two. The ones I'm looking at are:

OCZ GameXStream 700 W with 4x18amp rails

And

SILVERSTONE SST-ST75ZF 750W with 4x18amp rails

The OCZ is $125 and the Silverstone is $200. And the specs on the rails are the same excep the OCZ lists a higher 3.3amp rail for a lower rated voltage, which doesn't make sense to me.

Is the Silverstone worth the extra $75?

EDIT: Looks like I'll have to go with the OCZ. The Silverstone is 180mm long and the OCD is 140mm. The extra 40mm may not fit, and will definately block off important airflow in the case.

 

[Celada]

Imo if you are buying a 120+ dollar psu go pc power and colling or something like that.

 

[BlitzPuppet]

Yeah minimum for a single 8800 is 450W, so I bet it's a PSU problem.

 

[torin3]

Well, since I'm home sick I figured I would try with it off of the UPS and it shut down the exact same spot.

Ok, that takes the UPS out of the equation.

The OCZ 700 should arrive tomorrow, so I should have some numbers by the weekend.

Ugh...it is 70° in the house and I have a coat on because I'm freezing.

 

[torin3]

Well, the OCZ 700W PSU arrived today. Hopefully I'll have some updated 3DMark06 numbers tonight.

 

[torin3]

10894

 

[meionm]

10894

What's that?

 

[torin3]

What's that?

Sorry, I was in a bit of a hurry there. That was my 3DMarko6 score at 580/950 on Dual 8800GTSs.

With default clocks I was getting 10616, which is about a 2400 point gain over my default clocked score with a single card.

The card that has it's intake blocked by the 2nd card runs about 5°C hotter than the 2nd card. I should probably switch slots as the blocked card is also the one that doesn't overclock quite as well.

 

[dominick32]

Before continuing to finish reading the rest of this thread. It is definitely PSU related. Is there any chance that you had a digital multimeter handy and had the capability to monitor load/idle transitioning on 12v and 5v ? With a DMM You would be able to the see the drastic fluctuation in voltage causing the system instability if any at all.

 

[torin3]

It was definately a power supply problem. It seems to be running rock solid on the 700W OCZ GameXStream I got today.

 

[dominick32]

It was definately a power supply problem. It seems to be running rock solid on the 700W OCZ GameXStream I got today.

Sweet. I am glad that it worked out for you. Do we have any OC'ing results yet you lucky bastad???

 

[torin3]

Sweet. I am glad that it worked out for you. Do we have any OC'ing results yet you lucky bastad???

Not quite as high as I would like. I can get up to 580/950 with both cards, but that seems to be the top end for the second card. I think I'm going to switch them so that the lower clocking card can get more air. It gets up to the mid 60s. Plus I'll be getting two EK Eddy waterblocks for them in the next week, so hopefully that will help too.

At the 580/950 settings I get 10894 on 3DMark06, and on stock settings I get 10616 on 3DMark06.

 

[meionm]

Not quite as high as I would like. I can get up to 580/950 with both cards, but that seems to be the top end for the second card. I think I'm going to switch them so that the lower clocking card can get more air. It gets up to the mid 60s. Plus I'll be getting two EK Eddy waterblocks for them in the next week, so hopefully that will help too.

At the 580/950 settings I get 10894 on 3DMark06, and on stock settings I get 10616 on 3DMark06.

Aren't you two gfx cpu limited about now. I would assume 2x8800gts would do better than 8800gtx. With one 8800gtx and E6400 at stock speed I got 9100 and at 3.6ghz 11111 in 06

 

[dominick32]

Aren't you two gfx cpu limited about now. I would assume 2x8800gts would do better than 8800gtx. With one 8800gtx and E6400 at stock speed I got 9100 and at 3.6ghz 11111 in 06

You bring up a good point. Judging by my own testing on a single 8800GTX he looks to be very CPU bound with that setup. Think about it, based on these GTS results compared to my results. (amd @ 2.8ghz) 2 X 8800gts = 10616 in 3dmark06 stock vs. 1 X 8800gtx = 10,651 (e6700 @ 2.93ghz) stock

PS- You guys can read my two articles in full here:

http://www.overclockers.com/articles1388/


http://www.overclockers.com/articles1390/

 

[torin3]

Aren't you two gfx cpu limited about now. I would assume 2x8800gts would do better than 8800gtx. With one 8800gtx and E6400 at stock speed I got 9100 and at 3.6ghz 11111 in 06

Only for the CPU score. It stays in the 2139-2178 range no matter what the clocks on the card ar set to. It goes up and down a bit, but doesn't correspond at all to the clocks.

However, the other two scores go up pretty much linearly with the GPU clock settings.

And the only thing that isn't perfect in Oblivion is a slight 'jerk' as it renders a new chunk of scenery in high detail when you get close enough. It is the same with no HDR/AA or HDR/16AA, so it is probably CPU related. If I don't run, it doesn't do that.

I can move the mouse around like crazy and it is smooth as silk. It kind of makes me motion sick...