Which m.2 slot should i use?

[Brae]

hey guys!

 

Im currently building my first pc and I'm having trouble figuring out what slot I should use for my Samsung Evo Plus 970 2tb m.2 storage card.

 

My motherboard is the ASUS ROG Maximus XII Hero (Wi-Fi) z490 which has 3 m.2 slots. 

I am using the Samsung 970 Evo Plus m.2 as my main storage + OS for now as I have no other hard drives. I want to have it as Pcie 3.0 x4 mode and also keep it as far away from my primary GPU slot as possible.

Im so new to this kind of stuff so any help would be appreciated! 

 

In my motherboard's manual it says:

• M.2_1 and M.2_3 slots support PCIe 3.0 x4 and SATA mode Key M design and type 
2242 / 2260/ 2280 / 22110 storage devices.
• M.2_2 slot supports PCIe 3.0 x4 mode Key M design and type 2242 / 2260 / 2280 
PCIe storage devices.
• When M.2_1 is operating in SATA mode, SATA6G_2 will be disabled.
• M.2_2 shares bandwidth with PCIEX16_3. When M.2_2 runs x4 mode, PCIEX16_3 
will be disabled. When M.2_2 runs x2 mode, PCIEX16_3 runs x1 mode.
• M.2_3 shares bandwidth with SATA6G_56. When M.2_3 is populated SATA6G_56 
will be disabled.
• M.2 slots supports IRST (Intel® Rapid Storage Technology).

 

It says that I can use m2_3 in x4 mode but in the BIOS storage configuration drop down box i can only select "Auto" or "SATA Mode" in m2_3.

 

Link to my motherboard's manual for reference:

https://www.asus.com/Motherboards/ROG-MAXIMUS-XII-HERO-WI-FI/HelpDesk_Manual/

 

Thanks guys! 

 

My Build!: 

First PC build https://imgur.com/gallery/9W9CHs6

[Kanna]

The one closest to the cpu

[Brae]

1 minute ago, Kanna said:

The one closest to the cpu

Thanks for the reply! I cant use m2_3? I dont plan on using the sata ports. What's the benefit of having it closer to the CPU? 

[-rascal-]

@Brae @Kanna

 

Doesn't matter which slot you use, the PCI-E 3.0 X4 bandwidth for the M.2 slots are coming from the Z490 chipset, and not through the CPU.

The CPU only supplies 16 PCI-E 3.0 lanes, and those are wired to the primary PCI-E X16 slots.

 

 

Some older platforms (e.g. Z97 / Z170 / Z270) you have the option to choose the PCI-E bandwidth mode (e.g. X2 / X4), but it's all X4 or nothing these days.

Because the faster NVMe drives will use up all X4 bandwidth; you'd severely gimp performance if running it at X2 ....or back in the day, PCI-E 2.0 mode.

[Brae]

2 minutes ago, -rascal- said:

@Brae @Kanna

 

Doesn't matter which slot you use, the PCI-E 3.0 X4 bandwidth for the M.2 slots are coming from the Z490 chipset, and not through the CPU.

The CPU only supplies 16 PCI-E 3.0 lanes, and those are wired to the primary PCI-E X16 slots.

 

Some older platforms (e.g. Z97 / Z170 / Z270) you have the option to choose the PCI-E bandwidth mode (e.g. X2 / X4), but it's all X4 or nothing these days.

Because the faster NVMe drives will use up all X4 bandwidth; you'd severely gimp performance if running it at X2 ....or back in the day, PCI-E 2.0 mode.

Awesome! Thank you! So if I use m2_3 I should leave the configuration in the BIOS set to auto and that will run x4? The only other option I can choose in the dropdown box is "SATA Mode" but in the other 2 drop down boxes one has rapid x16 mode and x4 mode showing so im a little bit confused as to why x4 mode wont show in m2_3's box 

[-rascal-]

4 minutes ago, Brae said:

Awesome! Thank you! So if I use m2_3 I should leave the configuration in the BIOS set to auto and that will run x4? The only other option I can choose in the dropdown box is "SATA Mode" but in the other 2 drop down boxes one has rapid x16 mode and x4 mode showing so im a little bit confused as to why x4 mode wont show in m2_3's box 

 

Yes, leaving it on auto should take care of it.

"SATA Mode" is only there if you SPECIFICALLY need it to run at SATA Mode.

(e.g. you are using a M.2 SSD that is SATA instead of NVMe)

[Brae]

6 minutes ago, -rascal- said:

 

Yes, leaving it on auto should take care of it.

"SATA Mode" is only there if you SPECIFICALLY need it to run at SATA Mode.

(e.g. you are using a M.2 SSD that is SATA instead of NVMe)

Thank you so much! I shall try it out.