Built new system, isn't working right....

We just put together a machine, the specs are as follows:

CPU: i5-3570
GPU: XFX HD7850 Core edition (it's a 7870 board type, with cores shut down to be a 7850, has the 2x6pin rather than the usual 1x6pin 7850s)
MOBO: ASRock Z77 Pro3
RAM: Samsung 2x4GB "wondegreenstuff"
PSU: 450W Rosewill Capstone
HD: 256GB Samsung 830

The rest I can't imagine being important to the issues, but it has a 1TB Seagate for backup/storage, a "whatever was shipping free that day" DVD burner, and a CM Scout case.

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The first problem we had, was that the GPU refused to initialise. Some searching around suggested that switching the PCIE2 slot (this is the slot intended for primary GPU installation on this board) speed down to gen1 might work. It did. The GPU initialised and can be used as the primary display adapter. We updated the MOBO BIOS from 1.2 to 1.5. No improvement. At this point, my thought was that we would just live with it, because on paper, a PCIE 1.0 X16 slot should have the same bandwidth as a 2.0 slot at 8X, and 2.0 8X was not known for being able to bottleneck even very high end cards last I looked into it.

Windows installed just fine, first time through, got all updates, installed MOBO drivers. Performance seemed good. 15-17 second boot times. 7.6 on the windows-richter scale. supcom2 runs really smooth. No reason to suspect anything is wrong, but then, weird little issues start cropping up...

The computer runs stable and without ill effect under loads. I have run prime95 for about an hour, memtest86 for a few hours, several hours of gaming with no issues (I realise we would have to run these longer to establish absolutes, but...). The computer has problems when "left alone." Sometimes when we come back to it (after it has just sat idle for awhile), it will refuse to "wake up" with keyboard or mouse input. Then, upon a forced reboot, the wireless keyboard and mouse have "lost" their connection. The computer has on a couple occasions, shut itself down completely for no apparent reason. Again, this stuff only happens when nobody is around. On one occasion we came to it and it had an error message of sorts "Windows has recovered from an unexpected shut-down."

At first I was willing to write this crap off as stuff we will work out in time through changing settings and "avoiding" buggy problem areas in software or BIOS related issues. Curiosity struck me... I downloaded and ran 3Dmark11 to the machine and scored a dismal 5319 in the "performance" mode. Other machines with the same CPU/GPU/RAM are getting nearly double that. grrr I wouldn't expect PCIE 1.0 speeds to cause this much of a bottleneck. Any ideas as to what might be causing this?

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RMA the board? OEM windows has already been installed, can't change to a different board as far as I know. Would hate to get a replacement with the same problems. Reading around suggests that these problems are not unique to us. Especially the GPU recognition issue (inability to use PCIE3.0 speeds on ivy with a proper 3.0 card).

Anyway, I'm poking for some ideas on what to try, or what would be the most logical next step. I really hate tearing a whole machine apart to RMA a MOBO but it's looking like that's what we'll have to do.

Regards and thank you,
Eric
Edited by mdocod - 8/17/12 at 3:45pm

Hi Famia,

Thank you for sharing your thoughts on the matter.

We did have it set "not to sleep" but for some reason it seemed to want to sleep anyway sometimes... Though that behaviour seems to have gone away. The system is still set to turn off the screen, and sometimes still has problems "waking" even from that state, but I can't figure out if that problem is related to the keyboard/mouse loosing sync or perhaps the system is actually locking up... Hard to say at this point.

The GPU is in the correct slot. ( quote self: "this is the slot intended for primary GPU installation on this board" ). Unfortunately, the board only has the option of "Gen1" or "Auto." There is no way to force gen2 or gen3 operation, those operation modes are supposed to be auto detecting I suppose.

For kicks, I installed the GPU in the other PCIE slot on the board today, (an X4 2.0 slot, should be half the bandwidth of the X16 running Gen1), and the benchmark result only dropped 2%... If the Gen1 were really causing a bottleneck in the benchmark, then cutting the bus speed in half again should have had a much more profound effect, something else must be causing the poor benchmark result. Will keep tinkering

I think we will contact MS to see if they would allows us to swap to a different board under the OEM licence. There are some Biostar boards in the same price class that we may want to check into.

Regards,
Eric