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dogma1138yesterday at 3:29 PM4 repliesview on HN

There is fuck all difference between x8 and x16 for gaming. Heck with PCIe5 even dropping to x4 is borderline noticeable outside of benchmarks.


Replies

Sohcahtoa82yesterday at 4:41 PM

100% this

The PCI-Express bus is actually rather slow. Only ~63 GB/s, even with PCIe 5 x16!

PCIe is simply not a bottleneck for gaming. All the textures and models are loaded into the GPU once, when the game loads, then re-used from VRAM for every frame. Otherwise, a scene with a lowly 2 GB of assets would cap out at only ~30 fps.

Which is funny to think about historically. I remember when AGP first came out, and it was advertised as making it so GPUs wouldn't need tons of memory, only enough for the frame buffers, and that they would stream texture data across AGP. Well, the demands for bandwidth couldn't keep up. And now, even if the port itself was fast enough, the system RAM wouldn't be. DDR5-6400 running in dual-channel mode is only ~102 GB/s. On the flip side the RTX 5050, a current-gen budget card, has over 3x that at 320 GB/s, and on the top end, the RTX 5090 is 1.8 TB/s.

magicalhippoyesterday at 5:22 PM

Main problem seems to be they're kinda badly utilized (IMHO) on many motherboards. Most seem to go with two x16 slots so you get x8 lanes in both.

There are some exceptions, but I haven't seen one with for example four x16 slots that support PCIe 5.0 x4 lanes with bifurcation.

show 1 reply
johnbelloneyesterday at 4:42 PM

The biggest difference for me for PCIe 5.0 has been additional bandwidth for my M2 drive.

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Gracanayesterday at 4:57 PM

Your comment is basically the "tl;dr" of this Techpowerup article (which is great and people should read it if they are unconvinced or curious): https://www.techpowerup.com/review/nvidia-geforce-rtx-5090-p...