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io_uring is faster than mmap

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283 points ghuntley | 1 comments | 04 Sep 25 22:01 UTC | HN request time: 0s | source
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modeless ◴[05 Sep 25 03:25 UTC] No.45134728[source]▶
Wait, PCIe bandwidth is higher than memory bandwidth now? That's bonkers, when did that happen? I haven't been keeping up.

Just looked at the i9-14900k and I guess it's true, but only if you add all the PCIe lanes together. I'm sure there are other chips where it's even more true. Crazy!

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DiabloD3 ◴[05 Sep 25 03:41 UTC] No.45134790[source]▶
"No."

DDR5-8000 is 64GB/s per channel. Desktop CPUs have two channels. PCI-E 5.0 in x16 is 64GB/s. Desktops have one x16.

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1. pseudosavant ◴[05 Sep 25 05:28 UTC] No.45135236[source]▶
One x16 slot. They'll use PCIe lanes in other slots (x4, x1, M2 SSDs) and also for devices off the chipset (network, USB, etc). The current top AMD/Intel CPUs can do ~100GB/sec over 28 lanes of mostly PCIe 5.