NVIDIA GeForce RTX 5090 PCI-Express Scaling

[Cadasiso]

I was planning on building a new AM5 system along with a 5080 but might just keep my Taichi x370 PCIe 3.0 mobo and get a 5090 with the savings of not buying a new mobo and RAM. I play at 4k. What do you guys think?

It'd be fine, just slap a 5700X3X there and you're good for Ultra+RT, I don't think bottleneck is a major concern in 4K in newer, GPU bound games, it's not like there's any 4090 for reasonable prices anywhere in the world anyways, so even while bottlenecked it'll be a better deal (assuming you can get one). CPU scaling reviews might come soon, it'd wait for them before considering between the 5090 and 5080

 

[W1zzard]

Why didn't you compare the stutter intensities when VRAM overflows?

Still waiting for that 32 GB VRAM game

 

[_roman_]

It'd be fine, just slap a 5700X3X there and you're good for Ultra+RT

No - definitely not - a recent retest from a gaming magazine

Proof: https://www.pcgameshardware.de/Benc...iste-Index-Gaming-2025-Fps-Vergleich-1464279/

well Numbers are a universal metric which should be understood by mostly anyone.

The 5700X3d will cost you a lot of frames because of the outdated, old plattform. Ultra and Raytracing implies high end. Not entry level gaming, like gamig wiht a low cheap, outdated, old, ryzen 5700X3d with old DRAM Standard, old PCIE standard and such. that processor is also not really future proof for ultra and raytracing, e.g. year 2025, year 2026, year 2027

Ultra is above very high - is above high - is above medium high - is above light medium - is above medium - is above low - is above low.

Just to make clear - we are talking about ULTRA game settings with Raytracing. Not low end

 

[Haunter]

I really didn't expect that. Once I was testing different Pcie and Procyon, AI workload including some Time Spy and games, etc. are in average utilizing PCIE 4 on about 10%. AI workloads more, almost full bandwidth. So this comparison is really nice and detailed. And I really didn't expect 4080 to be better, than best card in the world, LOL, great step back, nVidia, really great... first nvlink, now this. Same like car manufacturers using eco leather...

 

[trsttte]

Too busy, 5090 custom, then more releases from NV, and maybe AMD manages to launch something, too

I get it, but if you could squeeze just a few tests even without comparing to previous generations would be worthwhile, this is something a lot of people will be looking for

How to test lower PCIEX generations with same motherboard?

Bios settings to either set the pcie generation or limit the number of lanes. If the motherboard doesn't have at least one of these options duct tape on the gpu pcie contacts does the trick.

Funny thing is can see Nvidia releasing it with only 4 lanes.

Probably not x4, but likely x8 like the 4060

 

[lexluthermiester]

Still waiting for that 32 GB VRAM game

That makes me wonder: What would a 5090 do at 8k?

 

[mouacyk]

damn i need my 1%

 

[nageme]

So to quickly sum up, PCIe bus versions are not a limiting factor to GPU performance.

A game or two there did show a more pronounced slowdown, at least at 1920x1080. I'm guessing it depends on how the game is designed.
Maybe games have learned, historically, to avoid relying too much PCIe traffic because of bandwidth limitations (or latency?). But as PCIe speeds up, new ideas become possible.

For example (though not really related to graphics bandwidth), old games never streamed level data. Maps always pre-loaded fully at the beginning, or at best at a few checkpoints.
But at some point someone realized it could be done. Later, others followed.

Most motherboards should have the option to limit the speed of PCIe in the bios/uefi.

What's it meant to be used for?

 

[lexluthermiester]

A game or two there did show a more pronounced slowdown, at least at 1920x1080. I'm guessing it depends on how the game is designed.

True, very situational. However, none of those results were anywhere near unplayable until you get below PCIe 2.0. 3.0 and 4.0 are still perfectly acceptable. With most titles one wouldn't notice the difference at all.

 

[Slackaveli]

I would love to see motherboards that only provide 5.0 x8 (essentially 4.0 x16) bandwidth to the GPU and reallocate the other 5.0 x8 lanes to M.2 and/or additional PCIe slots. I'd rather Give up 1-2% performance for much more expandability.

then you need my board- 5 gen5 at the same time on Godlike x870e.

 

[lexluthermiester]

Jay did a set of runs comparing and his numbers mimic the numbers W1zzard got;

So in reality, PCIe gen is not a factor for performance.