Hello , i just wanted know if i am bottleneck with two r9 290 on pci express 2.0 8x/8x my mobo is GA-990-XA-UD3 rev 3.0 , cpu AMD FX 8350 OC @ 4.4ghz.
Due to the fact that my r9 290 have no crossfire bridge , i think of an bottleneck and i'm not sur , very sorry for my bad english i'm french but know you on this subject?
Thank you every for any response
Your CPU, motherboard and video cards are well balanced for gaming. You can rest easy with the rig.
I have a chart I am working on for a R9 Fury which runs fine even with PCI Express 1.1 x4 so do not worry with PCI Express 2.0 x8 slots.
Guru3D did a good article comparing PCIe 1.1 x16 to PCIe 2.0 x16 to PCIe 3.0 x16 with the nVidia GTX 980 last year at 2560x1440, which is about 20% faster than the R9 290, in both single and SLI setups. PCIe 1.1 x16 = PCIe 2.0 x8 = PCIe 3.0 x4 in terms of bandwidth. There is technically a "bottleneck" of sorts in SLI, but it varies from between near 0% in Firestrike to 20% in Thief, with an average result of about a 10% speed reduction, but even then the frame rate is well above 60.
TechPowerup last year did a PCIe 1.1 vs 2.0 vs 3.0 comparison with the FuryX, but sadly neglected to do a Crossfire test, but even if the additional burden of handling Crossfire via PCIe reduced the effective bandwidth to PCIe 2.0 x4 levels, performance reduction would still be less than 10% loss vs x16
So don't worry about it.