16x vs 8x

[Noxia]

I cannot get my 6950 Twin Frozr III to run in 16x. It will not run in the primary PCI-E lane on two motherboards (error beeps for no VGA detected) yet it works in the secondary slots on both motherboards but only in 8x.
If I give up trying to solve this problem am I going to suffer a massive performance drop by running like such?
I don't wan't to pay to RMA this card only for OCUK to say it's fine but it might be worth it for peace of mind. I'm running a TX 650w PSU.

 

[Broken Hope]

There won't be any performance drop at all, though it's odd it won't run in the primary PCIe slot in 2 motherboards.

 

[Noxia]

There won't be any performance drop at all, though it's odd it won't run in the primary PCIe slot in 2 motherboards.

That's reassuring I suppose. You're right though it is odd and it does make me wonder if there is perhaps a defect on the card and I should pay to have it tested. On a + it comes with a 2 year warranty being MSI so thats also good.

 

[Muel]

Using 8x over 16x only results in a ~2% drop in speed. Tomshardware tested it a while ago.

 

[Noxia]

Thanks Muel, again it helps me feel better about the situation because solving has proved futile so far. I've read things baout the Hi Def wotsit for the HDMI causing issues and people removing it from hardware id 1002 but thats out of my expertise.
Here is a GPUz shot, anything alarming?


test by Noxia PSU, on Flickr


Weird thing is, I google imaged the same GFX card running at 16x but the figures are all the same!