Impact of PCIe 5.0 Bandwidth on GPU Content Creation and LLM Performance
6 comments
·July 3, 2025dweekly
zh3
I have noticed that for local AI at least, there is little difference between an old system (i3770/Asus P8Z77WS from 2012) which has 4 PCIe 2.0 x16 slots (supports 16/16, 16/8/8 or 8/8/8/8) running a pair of RTX3090s and up to date motherboards (with AMD9900x). Interesting to see a benchmark that bears this out - though for anyone who switches models a lot I'd assume a new system would be much quicker at that (from bandwidth improvements with newer CPUs,, nVME vs SATA and DDR5 vs DDR3).
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Calwestjobs
i can not see graphs
reason: "DataTables warning: table id=table_5 - Ajax error. For more information about this error, please see http://datatables.net/tn/7"
zh3
Click it enough times and the error goes away (howeever it looks like the tables further down the page are then broken).
jmrm
Happened the same to me
Fascinating and (to me) unintuitive result that these cards don't seem bandwidth constrained at PCI 4x16; the update to PCI 5x16 doesn't seem like it has any measurable impact on performance, allowing a PCI 5x8 configuration that "saves" some of your lanes at seemingly no penalty.
I wonder if we will have to wait another generation of cards (and apps) to make full use of a PCI 5x16 connection?