It supports it for sure, but will it actually consume it? Will someone with a motherboard that only supports PCIE4 need to upgrade for an RTX5090 or RTX5080?
Pure speculation: Look at the loss in performance between using a 4.0 card in a 3.0 slot, or using a x8 slot for an x16 card. It’s not historically been more than a 15% dropoff, and I would speculate also that there’s no big change to the data needed to rasterize and raytrace+denoise in current games on the new hardware.
Plus if some magic confabulation/hallucination graphics mode is possible, where a giant ML model is on the card and spits out ‘probably the right frame’ at high detail and frame rate, that’s something you pre-load while setting up the game rather than stream in from disk or main memory. (This magic new mode is a guess on my part, but there’s no tooling I’m aware of or contemporary games being converted to ‘AI blob’ format.)
Timeline: When will cards be available, anyway? March/April? Immediately at CES in January? Don’t let me get in the way of ‘must have teh latest’ but I’d suggest picking a new motherboard when you know you need 5.0x16.
K3n.
I wasn’t looking to upgrade my own motherboard, genuinely just curious.
There’s been more than one tech tuber that have said (as an example) that B850 isn’t worth it, but you should go for B650E instead of B650 because it has certain features. One of the features they will call out is PCIE5 for the next gen graphics cards, but the way I see it, it’s unlikely PCIE5 even for an RTX5090 will make a difference… you’re saying 15% is possible - that would be huge, I’m thinking it’s less than 3%.
I tend to agree with you, though there is one possibility in the 5000 series that might make it matter. The 5000 series will use GDDR7 memory, which is 32 GB/s speed (and may reach 36 GB/s with refinements), versus the 4000 series GDDR6X that does 22-23 GB/s. Will that translate to actually using the PCIe bus that much more? Maybe, maybe not. But in the absence of that, yeah, I suspect you’re right. Heck, you may be right either way. I do think PCIe 5.0 is still major overkill for most things and I’d LOVE if mobo manufacturers would provide an option of boards with a decent amount of 4.0 slots rather than 1 or 2 5.0 slots. The scarcity of slots in every available mobo below Threadripper level these days is maddening.
Debauer just released a video, testing this topic.
Turns out even PCIE3 is fine for a 5090.