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Z790-E refuses to use pcie 4.0x16 and only ises x8

Captaindooguls
Level 7

20230325_075516.jpg

 I have even used gpu-z and got the same under load or not. 

Things I tried:

-Reseating gpu

-went into bios and tweak pch configuration

-moved m2_1 to m2_2

14 REPLIES 14

Captaindooguls
Level 7

I resteated cpu as well and no go

Hopper64
Level 13

List all of your hardware for everyone to review. I wonder if using M2_2 drops the PCIe lane to x8.

MZ790E Bios 0904, GSkill F5-7800J3646H16GX2-TZ5RK, 13900KS, EKWB D5 TBE 300, Corsair 1600i, Asus Strix 4090 w/ Optimus block, Phanteks Enthoo Elite, Claymore 2, Gladius 3, XG349C, Samsung 990, Windows 11 Pro

Z790-e motherboard 

Msi gaming trio 4090

I9-13900k

1 sn850x

Galahad aio 360

64gb G.skill trident z5 rgb 64000mz ddr5

Hopper64
Level 13

Which PCIe slot are you using for the video card?

MZ790E Bios 0904, GSkill F5-7800J3646H16GX2-TZ5RK, 13900KS, EKWB D5 TBE 300, Corsair 1600i, Asus Strix 4090 w/ Optimus block, Phanteks Enthoo Elite, Claymore 2, Gladius 3, XG349C, Samsung 990, Windows 11 Pro

Hopper64
Level 13

Nevermind. I see the slot from the picture you posted. Consider removing the nvme drive and boot into the bios. Does that change anything?

MZ790E Bios 0904, GSkill F5-7800J3646H16GX2-TZ5RK, 13900KS, EKWB D5 TBE 300, Corsair 1600i, Asus Strix 4090 w/ Optimus block, Phanteks Enthoo Elite, Claymore 2, Gladius 3, XG349C, Samsung 990, Windows 11 Pro

Hopper64
Level 13

The manual unfortunately doesn't tell you about lane allocation, page 1-10. Is there anything connected to the SATA ports (page 1-11)?

MZ790E Bios 0904, GSkill F5-7800J3646H16GX2-TZ5RK, 13900KS, EKWB D5 TBE 300, Corsair 1600i, Asus Strix 4090 w/ Optimus block, Phanteks Enthoo Elite, Claymore 2, Gladius 3, XG349C, Samsung 990, Windows 11 Pro

Well, I'm going to have to buy a new board because it's stuck at x8 no matter where I place my m2. Maybe there is a bios eating shopping it but I tried everything from pch configuration to x16. I think I'll save up for a hero because I can't rma this card unfortunately. 

Also, there is nothing in the sata ports.

If m2 in slot 2 like on screenshot or 1 is normal it go 8x but using m2 in slot 3-4-5 must give you 16x