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.

[Atlantis852]

If you can return the M6E and switch to something else, that would be my recommendation at this point as there seems to be no real fix to the problem. I would highly recommend the Gigabyte G1.Sniper 5 if you do decide to return the M6E. It's everything the M6E should have been with a bit smarter layout.

I never expected that buying Asus's flagship motherboard would have turned into such a disaster for something as essential as SLI. Very Disappointing.

I am still planning to go ahead and build my second machine around my RMA replacement M6E (since I am stuck with it now) but I hope by the time I do, there will be some kind of fix for this issue.

[Raiden]

Sorry for duplicate the post, but I decided to copy my post in this thread also if it helps

It might sound funny, but for me, I just solved the problem ! Atleast as far as I can see after all tests I run.

I just update my M6E this morning to BIOS 0903 and for the moment works nice.

Already tested with BF3 and BF4, furmark performed and also 3Dmark Benchs, all FREEZES and CRASHES and low performance on 1 of the 2 GPU's like low GPU usage are GONE !

For the record, I'm running on:

4770K @4.5 Ghz + M6E + 2x 780 + 1200 PSU on Win7 SP1 64 bits

The video cards are on slot 1 and B2 running in Gen3 mode, recognized in bios as x8/x8

I really hope you also solve your problem with the new BIOS update (I had this issue for more than 1 month and also I tried almost everything)

[Atlantis852]

Raiden wrote:
Sorry for duplicate the post, but I decided to copy my post in this thread also if it helps

It might sound funny, but for me, I just solved the problem ! Atleast as far as I can see after all tests I run.

I just update my M6E this morning to BIOS 0903 and for the moment works nice.

Already tested with BF3 and BF4, furmark performed and also 3Dmark Benchs, all FREEZES and CRASHES and low performance on 1 of the 2 GPU's like low GPU usage are GONE !

For the record, I'm running on:

4770K @4.5 Ghz + M6E + 2x 780 + 1200 PSU on Win7 SP1 64 bits

The video cards are on slot 1 and B2 running in Gen3 mode, recognized in bios as x8/x8

I really hope you also solve your problem with the new BIOS update (I had this issue for more than 1 month and also I tried almost everything)

Shouldn't you be at x16 / x16 if in slot 1 and B2?

[Atlantis852]

Raiden wrote:
Sorry for duplicate the post, but I decided to copy my post in this thread also if it helps

It might sound funny, but for me, I just solved the problem ! Atleast as far as I can see after all tests I run.

I just update my M6E this morning to BIOS 0903 and for the moment works nice.

Already tested with BF3 and BF4, furmark performed and also 3Dmark Benchs, all FREEZES and CRASHES and low performance on 1 of the 2 GPU's like low GPU usage are GONE !

For the record, I'm running on:

4770K @4.5 Ghz + M6E + 2x 780 + 1200 PSU on Win7 SP1 64 bits

The video cards are on slot 1 and B2 running in Gen3 mode, recognized in bios as x8/x8

I really hope you also solve your problem with the new BIOS update (I had this issue for more than 1 month and also I tried almost everything)

Shouldn't you be at x16 / x16 if in slot 1 and B2?

[Atlantis852]

Can anyone else confirm (or deny) if the 0903 BIOS solves the B2 slot nightmare?

[Raiden]

Unfortunately not, this MoBo don't ave potential for dual x16. Only x8/x8 native

[Hopper64]

So, if 0903 fixes the issue, is it recommended to go back to the B2 slot per the manual, or is the slot under B2 just as good?

[Raiden]

Well, as far as I know running on the first slow and the next one under the B2 slot, which is the PCIE slot #3, was working good and stable until now. The only difference is running SLI on the slot #1 (red) and slot #3 (red) you are running once card trough the CPU an the second via PLX chip, which some people say it causes some latencies on the bandwidth.

Running the SLI on the slot 1 and B2, will be x8/x8 native.

Somebody correct me if I'm wrong.

[Atlantis852]

First, I think it's too early to declare 0903 fixes the B2 problem until we get reports from others who have been running it for a while with similar results to Raiden.

As far as cards being in Slot 1 and B2, I seem to recall that this is supposed to be x16 / x16 gen 3.

[Hopper64]

Changed my second card back to B2. Valley bench looks and performs quite well. Lost a few FPS in the min and max only. Stutters are comparable to the prior configuration. I think this runs at x8, not x16.