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Better performance from PCIe x8 slot than x16

  • Motherboards
Last response: in Motherboards
May 8, 2012 2:53:34 PM

I built this over the weekend:

CPU: i-7 3770K
RAM: G.SKILL Ripjaws X Series 8GB DDR3 1600
GPU: SAPPHIRE Radeon HD 7970 OC 3GB 384-bit GDDR5
PSU: COOLER MASTER Silent Pro Gold 1000W
HS: Noctua NH-D14
SSD: Corsair Force Series GT 240GB

Build was smooth, windows load and all updates smooth, temps normal, no o/c yet, only tweaked ram timings. Drivers are current, directx 11 installed.

After everything was updated and running, I installed and ran 3Dmark 11 basic. I didn't even let it finish because during the first graphics test it was maxing out at just 7 FPS.

I took the 7970 out and hit the pcie slot with some compressed air. Re-seated the card, uninstalled and reloaded the driver, but same results.

I don't know what these numbers are worth or what they are measuring, but I also noticed that the windows experience index graphics measurements were 4.4 (graphics) and 4.9 (gaming graphics). All the other three measurements were where I'd expect (7.7-7.9).

After a few more gpu re-seats, driver re-installations, and a re-load of windows, the problem persisted.

Then I decided to try moving the card from the top x16 slot (actually meant to run at x16) to the second x16 slot (runs x8). Surprisingly, my WEI graphics measurements went up to 7.7 and 7.9, respectively, and running 3DMark got me around 30FPS on average and a score of around 5000 on 'Performance'. Not very good at all, but not unreasonable from the x8 slot. The physics and combined scores were where they were supposed to was pulling it down.

I tried it in the x16 slot again but got the same results as before.

The 3D bios alludes to a place where I can check the status of the pcie slots and even disable them, but I could not for the life of me find anything like that.

I also ran GPU-Z. With the rendering test active, the card reported that it was rated for AND running at x16 v3.0. To me it seems like something with the motherboard, and I'm more likely to believe that I'm missing something than that I got a defective board. I'm planning on calling Gigabyte to see what they can offer, but any suggestions would be much appreciated!


More about : performance pcie slot x16

a b V Motherboard
May 8, 2012 3:37:28 PM

Its new build just call up there and rma your mobo :) 
for pci slots go to BIOS settings :) 

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a b V Motherboard
May 8, 2012 4:04:20 PM

Sorry if this sounds kinda basic, but did you update to the latest BIOS and try the "restore default settings" option?
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May 8, 2012 4:27:45 PM

I did restore the default settings and even tried a CMOS reset once. I did not update the BIOS though. Being that the board was released just a couple weeks ago I didn't even think to look. I see that there is an update 4/26. I'll give it a shot tonight.

Thanks for the replies
May 15, 2012 12:34:32 PM

BIOS update did not work on 5/8. However, on 5/11, a thrid BIOS revision came out that fixed the problem. Frustrating, but all systems are go. Thanks for the replies
May 15, 2012 12:34:51 PM

Best answer selected by theNimrod.
a c 331 V Motherboard
May 15, 2012 5:32:09 PM

This topic has been closed by Nikorr