Can anyone verify that the Asus WRX90E-SAGE board has x8/x8 bifurcation as an option? The manual seems to suggest that there is only x16, what I think is x8/x4/x4, and x4/x4/x4/x4 (what ASUS calls RAID?), but no x8/x8.
In contrast, the WRX80E WIFI that I have also does not list it in the manual, but my BIOS does have x8/x8 as an option. I also have a WRX80E WIFI II that both has it in the BIOS, and also lists it in the manual. So there seems to be no correlation.
According to this video: https://www.youtube.com/watch?v=iFgDxStELkA there is no x8/x8 as he is going through the BIOS options. Sucks if ASUS removed a feature that was on the earlier version. But he also had an early version of the board, and they may have added it back in a later BIOS update.
Would appreciate any input from current owners (I know there aren’t many).
I would expect 6 of the PCIe slots to have x8/x8 available if it is implemented, because they nerfed the 7th PCIe slot on the 90E compared to the 80E (it is only x8 instead of x16). Not sure why they did that, guess to add dedicated M.2 slots without sharing bandwidth with U.2/SlimSAS instead.
I’m running 13 GPUs on the 80E and would like to transfer that config over to 90E, but x8/x8 is a necessity!
Thanks, will wait and watch I guess. Sucks that ASUS didn’t carry it forward from the previous generation.
I can’t even rely on the BIOS update logs to tell me if/when they add the feature. There is no mention of it in the logs for 80E, and yet I know they added it in one of the updates.
I have had not had much success communicating things like this to them either. There has to be some way to talk to the EPYC board support team or something, but I haven’t found it. Good luck!
There was a random bios update a couple of weeks ago however it did not add and new bifurcation options. It seems for the WRX80 x8x8 supports was added in just a random BIOS update in its life cycle. Wasn’t event documented
Is it slots 4,5,6,7 again that has the built-in re-drivers on the WRX90?
Those have honestly been a huge pain to deal with in the WRX80, ASUS probably didn’t use very high quality re-drivers. I’m beginning to see the wisdom in packing more MCIO ports closer to the CPU instead of slots. You can drive or re-time the MCIO however you need later.
Oops, my bad! Yes I meant 5,6,7, it is the same with the WRX80 versions also.
Also, the C-Payne PCIe switch I mentioned earlier has an issue with ADA-class NVidia GPUs presently: they are forced into PCIe Gen3. Christian tells me there is a fix on the way via a firmware update soon.
EDIT: The software fix did it, now I can do better than x8/x8 and get full x16/x16 gen4 on x16 gen5 with no bifurcation.
That still works to bypass bifurcation: Gen3 x16 = Gen4 x8, which is what the bifurcation would do on a Gen4 platform at least. The fix would be needed to take advantage of Gen4 x16 on Gen5 platforms.
In regards to your concern about multiple GPUs running at 8 lanes on the motherboard, our Technical Support Department would like to confirm the following:
"Is customer willing to accept special BIOS for added X8+X8 option?
Which BIOS version was the customer willing to base on to build a special BIOS?
Did the customer add one special PCIE slot, the X8+X8 option, or all PCIE slots?"
Looks like I might be making progress with customer support to get this added
@grimulkan I would love to know the answer to this because I bought a WRX90 when they first came out and it sucked! I had to return it and get a WRX80. With the 5090’s around the corner I want to be ahead of the curve, but if this board doesn’t have 8x8x bifurcation, it’s not worth it.
Let’s hope crnoddin’s request gets some attention then! I too returned my bord so someone else would need to verify if they ever add it. If you are desperate, external PLX switch still works, though is additional cost.
Indeed great news. We need x8/x8 for at least the first slot. Be nice of all the 16 lane slots could do x8/x8. Please let the forum know when the new BIOS is ready. Any ETA?
Please let us know if Asus support was able to provide you with a special BIOS that includes x8x8, looking into building an 8x4090 setup by bifurcating one of the x16 slots.
