I am trying to get greater than 64 GB/s speed in 3DMark PCI Express Feature Test before installing a new pcie 5.0 riser from LINKUP.
linkup was able to get 120 GB/s in the test
https://www.youtube.com/watch?v=Y5h_vj5oURU
I am only able to get 57.82 GB/s which is half of what I was expecting without the riser installed yet: https://www.3dmark.com/3dm/136026398
I have enabled resizable bar, gpu z reports the bus interface at x16 5.0. I have 8000 mhz cl38 ram, an Asus X870e hero motherboard, 9950x3d, rtx 5090, turned off gsync, have my ssds in slot 4 and 5 which should not affect the first pci-e slots speed, I am scratching my head at why I cannot achieve this speed without the riser.
Furthermore, I have checked on cuda-z I am getting 51 GiB/S from GPU to Motherboard which should be correct
On Aidia I am getting ~54000 MiB/s which should also be around the correct number
I am not sure what to do here to fix the problem, would like some help form someone knowledgeable on this.
Hwinfo64 reports that the link speed is 32 GT/s
1 Comment
Pcie 5.0 x16 has a 64 GB/s bidirectional bandwidth for a total of 128 iirc – so the highest we should see is 64 one way – with some of it reduced due to overhead I’m seeing 57.71 GB/s on 5.0 x16 with rebar on in 3Dmark. I previously tried 5.0 x8 and got 28.88 which is consistent with a theoretical 32 GB/s. I’ve seen those higher results (~120) but afaik and from what I’ve been able to gather on the overclock.net 50 series thread, it was an earlier driver bug in rebar – unclear if it was functionally an increase in bandwidth or not. I think you’re getting the right values if you’re seeing high 50s in 3Dmark, though.