Running at x8

[tw33k]

I'm looking at getting a Radeon 5850. I have 2 x16 slots but 1 of them has a SATA 6/USB 3 card in it so the slots now have a max of x8. Will I lose much performance with this card running at only x8? I can't move the SATA card or my SSD won't perform at it's best.

 

[Hopalong X]

...and the SATA card has to have the 16x lane to work right?

 

[tw33k]

Correct

 

[Hopalong X]

Well they both only work at 8x if you SLI or Crossfire.

The slots are independent otherwise. You cut the performance way down using the 5850 in the 8x lane.
Might only get 50-60% of performance. Could be 70%.
If the SATA would go in the 8x you would be okay otherwise it- fill in the blank.

Looked up your mobo. I don't see a way around it.

 

[A Guy]

I think the consensus is you'll lose approx. 5 - 10% performance going from x16 to x8. This seems to be what's expected for the SATA card as well.

Found this:

Conclusion : PCI Express And SLI Scaling: How Many Lanes Do You Need?

A Guy

 

[tw33k]

From what I've read it seems the drop would be very minimal (2-5%) but I wanted to check here to see what others say.
Hopalong...as I said, both slots are x16 but cut down to x8 when both are used.

Thanks guys.

 

[Hopalong X]

Okay.

 

[imeem]

well you can do a benchmark with the gpu on x16 and x8 and see how much the difference is "exactly"

 

[thefabe]

My understanding of using the 8x bandwidth you should really only see a minimal drop in performance in highly demanding graphics games. In most circumstances fully saturating the 8x bandwidth just doesn't happen.
Then that was a few years ago before games like Crysis, Batman Arkyum Asylum, or any newer DX10 or 11 games.
I still wouldn't expect you should see any major loss of performance in most games/programs.
Fabe

 

[tw33k]

Yeah..that's my understanding too. Thanks fabe!