if pcie ssd downgrade first pcie graphic port ?

[afomek]

I have question about support of PCI-E.
it is written that for graphic sli or amd crossfire ports on this board are 8x
but what with SSD revo drive on 4x PCI-E and my R9 290 on 16x slot working on 8x becouse of ssd.

When i put off my revo from the rig bios show 16x on firs slot , when i put in revo it's 8x

I can't benchmark actually differences becouse of system only on revo. 😞

Please provide answear if system can cope with it?

i7-4770k
2400Mhz 16gb
formula vi maximus
asus r9 290 dc2oc 4gb
revo X2 drive 240gb
some others SATA'S
lot of fans

[Praz]

Hello

The 3 PCIe x16 slots are connected to the CPU. Anytime either the second or third slot is populated the first slot will be set to x8. This is how the system is designed because of the limited number of PCIe lanes of the CPU.

[afomek]

Praz, so tell me, if in Your knowledge about amd drivers there is difference in performence of pcie 3.0 x8 / pcie 3.0 x16 for asus r9 290 4gb 512bit dc2oc? it's worth putting off revo for good 512gb ssd on sata III ?

[Praz]

Hello

Both the video card and slot it is in should be at PCIe 3.0. PCIe 3.0 x8 is equivalent to PCIe 2.0 x16 so there should be no performance issues seen.

[afomek]

Thanks,

and first issues for this problem, was wrong driver in crysis 3 but in end i had to reinstall the game and it goes smoothly now,

[Praz]

You're welcome. 🙂

[afomek]

Praz tell me one more

if i have setted revo on 4x and will put second r9 290 it will hold pcie 3.0 4x, this will be problem if it do not worok in 8x as first one ?

[Praz]

Hello

Unfortunately SLI will not work without a minimum of 8 PCIe lanes regardless if those lanes are 2.0 or 3.0.

Edit: Missed the part about r9 290. CrossFire does work with 4 PCIe lanes although I don't know what type of performance hit this may incur.

[Menthol]

afomek,
I am not 100% sure but I believe AMD crossfire will work at pcieX4, Nvidia sli needs minimum x8, I have not tried this myself to verify

[afomek]

but how find out before buing one