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Rampage VI Apex + 7820x - M.2 Only running at 2x

Dingleweed
Level 7
Hello, I've recently updated the BIOS on my APEX board to the latest 3501 version and installed windows 11 but noticed I had some disk access issues.

The problem I've found is my Samsung 960 is using PCIe 3.0 2x.

I've got the 28-lane 7820x, with one graphics card, and the 960 pro plugged into the DIMM.2_1 socket of the CPU DIMM.2 slot.
I've turned off SATA, USB 3.1, Wifi, Bluetooth, Audio and a few other things as I don't use much. Looking at the manual and reading other posts it seems that the DIMM.2_1 slot should support x4 speed which should let me 960 stretch it's legs but I can't seem to force the board to use that spec. It always seems to connect at x2 and limit my speeds to around 1700mb/s.

I'm also using the latest ME version.

Any help would be appreciated.

Thank you.
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3 REPLIES 3

G75rog
Level 10
A 79xx series cpu would solve that. The 7820 just doesn't have enough pci lanes to support all the Apex functions.

I run an Apex with a 7900x and 8 nvme drives all running pcie 3.0 4x. Happy machine.

Silent_Scone
Super Moderator
Hello, as above the lower SKU CPU have reduced lanes on this platform.
13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

Dingleweed
Level 7
I heard this but the manual does say otherwise. I bought an i9-10900x as a little upgrade, but decided not to go ahead with the purchase as it had some heavy heat damage on the underside. I did use it briefly to check the motherboard/SSD. I had the extra options available in the BIOS regarding the other PCI slots, but the SSD still ran at x2.

Plan B was to purchase a small PCI m2 card to test the SSD in a regular PCI slot. It still ran at x2.

90260

Seems it's the SSD that's the issue! Problem solved. Now I've got issues setting up a RAID... haha might just have to keep CPU hunting. 😄