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M.2-1 Configuration in BIOS

Beerlord
Level 8
I have the Maximus X Hero MB and a 970 EVO 500gb drive in the M.2 slot but when I look in the BIOS to see if there are any settings, I only see 2 places for any possible changes and I'm not at all familiar with them.
One is listed as the M.2-1 Configuration with choices for Auto-SATA-PCIe (and is set to Auto)
The other is M.2-2 PCIe Bandwidth Control and is set to X2 but there is an option to set to X4.

So, what should these be set too?

Thanks in advance for your help.
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19 REPLIES 19

chevell65
Level 12
You want to use PCIe and X4 when possible.

More than one GPU gets you X2 mode.

Thanks. And making that change won't affect the current info on the EVO drive, meaning, I won't lose anything on it?

I just realized too I never even went to Samsung's site and download the driver though I'm not sure that will change anything.

mrvortep
Level 8
I have a 970 PRO 1Tb Samsung NVMe drive in the main M.2 slot on my Hero X. Regardless of whether I set the M.2-2 PCIe Bandwidth Control to x2 or x4, every time I reboot and enter the BIOS it has always reverted to x2. This is the case whether I have the first M2-1 option set to Auto or PCIe. It *always* reverts to x2 when I go into bios. Anyone else not have it revert to x2?

I've left mine to Auto for now but have not tried changing X2 to X4. Do you have yours set to PCIe or Auto.

Doing some net research, the opinions are many. Some say to leave it to auto and try X4 and others say Auto is the same as PCIe and set that to X4.

Beerlord wrote:
I've left mine to Auto for now but have not tried changing X2 to X4. Do you have yours set to PCIe or Auto.

Doing some net research, the opinions are many. Some say to leave it to auto and try X4 and others say Auto is the same as PCIe and set that to X4.


Set it PCIe, it should automatically default to X4. You can verify the interface through Samsung Magician software.

Yes, install the Samsung NVME driver, it's faster than the generic MS driver.
Intel i9 10850K@ 5.3GHz
ASUS ROG Strix Z490-E
Corsair H115i Pro XT
G.Skill TridentZ@ 3600MHz CL14 2x16GB
EVGA RTX 3090 Ti FWT3 Ultra
OS: WD Black SN850 1TB NVMe M.2
Storage: WD Blue SN550 2TB NVMe M.2
EVGA SuperNova 1200 P2
ASUS ROG Strix Helios GX601

Thanks much!

mrvortep
Level 8
Mine stays at x2 even if I manually change the setting to X4 - if I go back into the BIOS after a reboot it is back to X2 every time. This happens whether I set the first option to Auto or PCIe. What could this possibly be the result of...?!


That said, if I run Samsung Magician, it says the Interface is "PCIe Gen. 3 x 4".

mrvortep wrote:
Mine stays at x2 even if I manually change the setting to X4 - if I go back into the BIOS after a reboot it is back to X2 every time. This happens whether I set the first option to Auto or PCIe. What could this possibly be the result of...?!


That said, if I run Samsung Magician, it says the Interface is "PCIe Gen. 3 x 4".


This is normal behavior, in bios M.2-1 refers to your primary M.2 slot and M.2-2 to the second slot.
If you have your m.2 drive installed in the first slot on your motherboard, in bios select pci-e mode for M.2-1 to get PCIe Gen. 3 x 4.

The M.2-2 PCIe Bandwidth Control is for the second M.2 slot on the board, it always stays at x2 mode by default and does not affect the speed of your first slot.
Only if a drive is connected on that secondary slot and supports pci-e x4 you can change the value to x4 mode without it reverting to x2 mode.

And by the way the M.2 drives get their lanes from the chipset so your gpu will still run in full pci-e .3 x16 mode.

kens30 wrote:
This is normal behavior, in bios M.2-1 refers to your primary M.2 slot and M.2-2 to the second slot.
If you have your m.2 drive installed in the first slot on your motherboard, in bios select pci-e mode for M.2-1 to get PCIe Gen. 3 x 4.

The M.2-2 PCIe Bandwidth Control is for the second M.2 slot on the board, it always stays at x2 mode by default and does not affect the speed of your first slot.
Only if a drive is connected on that secondary slot and supports pci-e x4 you can change the value to x4 mode without it reverting to x2 mode.

And by the way the M.2 drives get their lanes from the chipset so your gpu will still run in full pci-e .3 x16 mode.


Thank you, that's very clear!