Question What bios setting to set for installing a new M.2 NVME SSD boot drive

angiemike6

Junior Member
Nov 15, 2022
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I currently have an Asus Tuf Z390 Gaming Plus motherboard with an Intel Core i7 8700 processor and 32 gb ram. I have a small Adata NVME SSD in the M2_1 slot which was installed by local computer shop on which the OS is loaded. In addition I have an internal Sata SSD and an internal HDD. I have a UEFI bios and am running Windows 11 version 22H2. In the PCH Storage configuration I currently have the option of AHCI or RST, and it is currently set to RST. I am not aware that I have RAID set up, but Speccy mentions that my current Adata NVME RAID Type is Software RAID.

My intention is to purchase a 2tb gen 3 NVME SSD and install it in the M2_1 slot moving the existing Adata SSD to the M2-2 slot. I will do a fresh install of Windows 11 and have already created Windows 11 Installation media on a bootable USB.

I do not fully understand the difference between AHCI and RST. Could someone advise me which setting is best for my proposed configuration, and what other changes if any I should make to my BIOS before installing windows 11. Any further advice for making any other changes would be appreciated.

Thank you.
 

daveybrat

Elite Member
Super Moderator
Jan 31, 2000
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These sites that you posted on:



Just curious as to how you can forget so quickly when one of them you posted on this morning? :rolleyes:
 

angiemike6

Junior Member
Nov 15, 2022
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daveybrat. I am not very impressed with the sarcastic replies to my posting. Instead of trying to belittle me in your responses you could have spent the time giving me some helpful advice. When you mentioned my question having been answered on 2 other forums, I assumed you meant other forums within AnandTech.

I am a novice at computer building, and am looking to purchase a 2tb NVME SSD on the Black Friday sales. I have been researching on the internet what I need to do to install it correctly, to get the best speed, and to do a fresh Windows 11 install. Unfortunately, the advice in various articles and forums seems split between setting BIOS to AHCI or RST. I therefore joined a few forums to ask a question specifically about my intended setup.

Are you saying that if I post a question on another forum, I cannot post a question on Anandtech. I posted on all the forums at more or less the same time, hoping to get some consistent replies.

In the Tomshardware forum the reply merely says ‘AHCI. Leave the Intel RST out of it.’ No further explanation or help.

In the elevenforum forum, I agree that the recommendation is to use AHCI, and there is more helpful information. I had not read this when I responded to your earlier post.

In the Techsupport forum it suggests that there is no difference between the two, and to leave my BIOS as it is. I.e. with RST enabled.

In the Bleeping Computer forum, the response is ‘Don't make any changes to your BIOS; you have a modern board and it is all set to go’. My BIOS is set to RST, and if you click to change the BIOS to default settings it remains as RST.

As you can see opinion is still divided. Perhaps the best is to leave the BIOS as is, as mentioned in the Bleeping Computer post, with RST enabled, and see how I get on.
 

Tech Junky

Diamond Member
Jan 27, 2022
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@angiemike6

If you have it set as one or the other and change it the PC won't boot.

Leave it alone and if you do a BIOS/UEFI update and it doesn't boot then you toggle it and things start working again. The setting has nothing to do with the speed of the drives you're using.


KISS is your friend when it comes to this setting. AHCI makes life simple and doesn't complicate things.
 
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angiemike6

Junior Member
Nov 15, 2022
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Thank you Tech Junky. Can I just check one thing with you. If I am installing Windows 11 from scratch, I understand that I need to set the BIOS to either AHCI or RST before installing, or as you say it may not boot. Bearing in mind I will end up with 2 NVME SSD's, one SATA SSD and one HDD internally, would you set BIOS to AHCI or RST. Thanks.
 

Shmee

Memory & Storage, Graphics Cards Mod Elite Member
Super Moderator
Sep 13, 2008
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RST is basically used for RAID or caching to my knowledge, and since you will not be running either from the sounds of it, better to use AHCI. Now I might be wrong here, but to my understanding NVMe drives are not affected by this setting, as they use the NVMe protocol, not AHCI/RAID. This should only be regarding the SATA controller on your motherboard.

All that aside, the recommendation above stands, since you are not doing RAID or using a caching drive, AHCI is simpler and should be selected in this instance.
 

Tech Junky

Diamond Member
Jan 27, 2022
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AHCI is the preferred method.

Whenever you flash the BIOS/UEFI though in the future it will default back to RST and won't boot until you switch it back.
 

daveybrat

Elite Member
Super Moderator
Jan 31, 2000
5,743
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daveybrat. I am not very impressed with the sarcastic replies to my posting. Instead of trying to belittle me in your responses you could have spent the time giving me some helpful advice. When you mentioned my question having been answered on 2 other forums, I assumed you meant other forums within AnandTech.

I am a novice at computer building, and am looking to purchase a 2tb NVME SSD on the Black Friday sales. I have been researching on the internet what I need to do to install it correctly, to get the best speed, and to do a fresh Windows 11 install. Unfortunately, the advice in various articles and forums seems split between setting BIOS to AHCI or RST. I therefore joined a few forums to ask a question specifically about my intended setup.

Are you saying that if I post a question on another forum, I cannot post a question on Anandtech. I posted on all the forums at more or less the same time, hoping to get some consistent replies.

In the Tomshardware forum the reply merely says ‘AHCI. Leave the Intel RST out of it.’ No further explanation or help.

In the elevenforum forum, I agree that the recommendation is to use AHCI, and there is more helpful information. I had not read this when I responded to your earlier post.

In the Techsupport forum it suggests that there is no difference between the two, and to leave my BIOS as it is. I.e. with RST enabled.

In the Bleeping Computer forum, the response is ‘Don't make any changes to your BIOS; you have a modern board and it is all set to go’. My BIOS is set to RST, and if you click to change the BIOS to default settings it remains as RST.

As you can see opinion is still divided. Perhaps the best is to leave the BIOS as is, as mentioned in the Bleeping Computer post, with RST enabled, and see how I get on.

My apologies, it's just that we get a lot of spam on the forums with bots that cross-post across multiple forums. Welcome to the forums and as the other members have stated, AHCI is best although it only affects Sata based hard drives, not your NVMe SSD's so it really doesn't matter. You'll be fine with whatever you set it to.