AHCI or Intel RST premium controller?

jarablue

Gawd
Joined
May 31, 2003
Messages
859
This is my situation. I have 1 m2 nvme ssd drive and 2 sata ssds. If I change my bios to use the intel rst premium controller from ahci, I can't see my nvme in the bios anymore. I can still boot to it, but it just disappears from the bios. If I set the bios to ahci, I can see it.

I raid 0 my 2 sata ssds so I need to use the rst premium controller. But am I losing any performance from my nvme by NOT using AHCI? It should perform just as fast with rst enabled right? Also for some reason my nvme is getting lower benchmark scores than what I am seeing on the web. I get 3000mb seq reads and 2600 sequential writes. Benchmarks online are getting 3400 and 2900. Wonder what could be going on there. I'm running gen3x4 I have the absolute latest drivers/firmwares for my system.

Thanks!
 

kirbyrj

Fully [H]
Joined
Feb 1, 2005
Messages
26,901
You're getting lower benchmarks because you are running your system off of the drive. If it were just an additional drive, it would benchmark higher.

Not sure about the AHCI vs Intel RST. I guess benchmark them both and see what happens? It shouldn't really affect it because (in theory) AHCI isn't compatible with NVMe. They are two different interfaces. Your NVMe drive NEEDS NVMe enabled to see it. My guess is that it has something to do with the SATA ports, not necessarily the M.2 ports.
 

Shikami

Gawd
Joined
Apr 5, 2010
Messages
735
The ONLY reason to ever have the software and driver installed for the RAID controller is for that exactly. If the controller maps the NVMe (Premium) you will not be able to "see" particular attributes as some things are not compatible via the interface that Intel provides. Having the controller in AHCI mode and the driver, not even the Rapid Storage interface is necessary, as many other options for drive information parsing exist and are better. So, in your situation install but do not map to the controller. I experimented before a new install of the OS with the "Premium" controller, and for my 970 and 960 the Samsung driver was much better and can also interface the information that I wanted to see via many applications (e.g. CrystalDiskInfo, Samsung Magician).

Benching varies, and you want to be more horseshoe and hand grenades-within the margins. As long as you are near that performance mark, you are within the boundaries of your performance that is to be expected. You cannot go by the sites that overclock, may or may not have C-States disable, etc. You have to consider what you have and them, and how both systems are configured to be benched. To note, that there are some function(s) of NVMe drives that are not handle by default Windows drivers therefore having the driver installed can have a minor affect. A latter Windows did not have a supported function for NVMe and the Samsung driver did, as an example.

To note, the NVMe is not in AHCI mode, it is mapped through the RST controller. I would possible prefer this instead of the default Windows driver if one is not provided by the manufacturer.
 
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