GTX780 ACX SC unstable performance on MVIE Slot 3(B2)

[MetroRat]

I have experienced some issue with this motherboard. The third PICE slot from the top, aka PCIe 3.0/20_x8_B2, is causing any graphic card that sit on it performing poorly. I noticed this issue when my two GTX780s in SLI configuration, installed on slot 1 and slot 3 as Asus suggested, gave me poor performance in a random pattern. 2 out of 10 system restarts its benchmark results would go very low than it should, meanwhile the CPU would also be busy occupied by system interrupts, making browsing the internet painfully slow. To narrow down the cause of this issue, I reconfigured the SLI to slot 1 and slot 4(at a disadvantage of not using the native PICe lanes of the chipset) and restarted and tested the system for 10 times. Everything turned out to be fine which eliminates the possibility of bad graphic card/driver. Then I put a single graphic card on slot 1 and tested 10 times, no problem. However, when I put the same card on slot 3 and tested it for 10 times, the poor performance issue appeared again in the same pattern as it was in SLI slot1 and slot3 configuration.

Does anybody here have this kind of issue also? Or should I contact the seller for a replacement?

BTW:My power source is AX1200i, and I'm testing it using dual EVGA ACX 780SC with the case open to keep them under 75 celsius degree.

[tObber]

It seems that the 1002 BIOS is the "best" so far. I am using the default settings.

If i change from PCI-E 3.0 to PCI-E 2.0 , my benchmarks is stable all day long without problem. And this has been with all the BIOS i have tried.

/Cheers

[shakaw]

Just a little update.
Have been running the 1002 BIOS for a few days now. So far so good, the system has been rock stable.
Windows 8.1 (clean install), EZ_Plug connected, no pci_e related BIOS tweaks, the rest is in my sig.
Got 18556 in FireStrike - http://www.3dmark.com/fs/1164170

[TL]

New Bios 0078
https://www.asuswebstorage.com/navigate/s/C25C2196C6E341BCA13BE014D032E36DY

if 0076 is best for you, select mode 2 in Gen3 Compatibility Mode

[tObber]

BIOS 0078, best so far on my setup, on first run everything is fine it seems.

But the longer the benchmark goes, the fps starts to come down and stuttering start to appear.

I Also tried "compatibility mode 2" but it just made things worse

[tObber]

Has anyone else with the EVGA GTX 780 3GB SC ACX card, been able to run stable?

[shakaw]

tObber wrote:
Has anyone else with the EVGA GTX 780 3GB SC ACX card, been able to run stable?

I had EVGA GTX 780 Classys for a couple weeks. They ran perfectly stable with the test BIOS.
I know it's not quite the same, and I thought it was graphics card related for a while, but I've had a chance to try this with 680s from ASUS and 780s from EVGA, and the problem was present with both.

[djdelirius]

tObber wrote:
Has anyone else with the EVGA GTX 780 3GB SC ACX card, been able to run stable?

I've got 1 780 EVGA Classified and 1 780 EVGA reference card on bios 0076 on MVIE w/4770k and I can run games stable, benches stable(Firestrike Extreme, Hwbot Heaven 1.03, basically any Furturemark bench) but I am getting crazy low scores. My Classy by itself scores almost 3 times better than the same Classy with another 780 in SLI.

I haven't been able to figure out what's wrong with my setup yet. I'll prob try the 0078 or 1002 bios sometime within the next week. I'm about finished with this setup and thinking about selling the cards and upgrading to the 780ti Classy when it comes out.

Does everyone who has these problems have EVGA cards or is it just SLI in general?

[tObber]

well, when I said stable, I didn't mean that my system crash, BSOD or anything anymore. That seems to be fixed since the 0078 or 1002 BIOS

It's just that I lose fps and stuttering appears, the longer the Benches/test progress. But if change from PCI-E 3.0 to PCI-E 2.0 in BIOS, or switch my second card to x8_3 slot everything is fine. So i definitely know that it is not a driver issue or something like that.

@djdelirius: Give 0078 or 1002 BIOS a shot, and see if it fixes your issue.

/Regards

[Hopper64]

0078 looks pretty good here. Mild stuttering in Valley, but I can't tell if that's just normal. Not much different from 1002 or 0076.

[djdelirius]

So I did quite a bit of testing earlier. I've only tried 0076 and 0078 BIOS' while using Firestrike Extreme in all tests with the same graphics cards vBIOS and settings. All were done with an EVGA Classified 780 (custom vBIOS, no boost enabled) as the master card and an EVGA Reference 780 (custom vBIOS, no boost) as the slave.

As you can see below, all the results are terrible for an SLI 780 setup. A single 780 gets around 2 to 3 times the scores on the same tests.

Here are my results:


With 0076 BIOS:

With slave card in the x8_B2 slot with Gen 3/Auto Settings in BIOS:
Score: 2368
Graphics score: 2232
Physics score: 12253
Graphics test 1: 11.05
Graphics test 2: 8.65
Physics test: 38.90
Combined test: 6.30

With slave card in the x8_B2 slot with Gen 2 Settings in BIOS:
Score: 1651
Graphics score: 1505
Physics score: 12436
Graphics test 1: 7.38
Graphics test 2: 5.38
Physics test: 39.48
Combined test: 4.90

With slave card in the x8_3 slot with Gen 3/Auto Settings in BIOS:
Score: 2378
Graphics score: 2245
Physics score: 12171
Graphics test 1: 11.14
Graphics test 2: 8.69
Physics test: 38.64
Combined test: 6.28


With 0078 BIOS

With slave card in the x8_B2 slot with Mode 1 Compatibility Settings in BIOS:
Score: 2370
Graphics score: 2234
Physics score: 12365
Graphics test 1: 11.05
Graphics test 2: 8.67
Physics test: 39.25
Combined test: 6.28

With slave card in the x8_B2 slot with Mode 2 Compatibility Settings in BIOS:
Score: 2362
Graphics score: 2225
Physics score: 12373
Graphics test 1: 10.95
Graphics test 2: 8.67
Physics test: 39.28
Combined test: 6.28

With slave card in the x8_3 slot with Mode 2 Compatibility Settings in BIOS:
Score: 2372
Graphics score: 2237
Physics score: 12415
Graphics test 1: 11.04
Graphics test 2: 8.70
Physics test: 39.42
Combined test: 6.27

So as you can see, none of the BIOS effected the score. The only modifier seems to be the Generation settings. I'll probably post some more scores for the 1002 BIOS when I get some time.