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Switch from Raid to AHCI
Is there a way to switch from Raid to AHCI without losing everything and having to reinstall Windows again?
Is there a way to switch from Raid to AHCI without losing everything and having to reinstall Windows again?
1. Run MSCONFIG
2. Enable Safe Boot (minimal)
3. Reboot into UEFI/BIOS and change to AHCI
4. Boot up into safe mode
5. Run MSCONFIG and disable Safe Boot.
6. Reboot
Download: Intel Rapid storage technology:
Downloads for IntelĀ® Rapid Storage Technology (IntelĀ® RST)
Post images into the thread of status, manage, and performance tabs
And do be sure you have a copy elsewhere of anything you don't want to lose, that exists nowhere else. Any time working with drives one risks possibility of something failing at the worst time.
Is there any advantage to switching to AHCI?
I'm assuming you're talking about Intel RST when referring to RAID. In theory, if you don't enable any RAID features then there should be no difference - Intel RST sits on top of AHCI so if you don't have RAID configured then all drive commands should just pass through the RST layer to the AHCI driver.
Indirectly, there may be some marginal performance difference depending on whether you use the RST or AHCI driver - Forum - Performance of the Intel RST/RSTe AHCI/RAID Drivers
Another thing I can think of is that boot may be slightly faster in AHCI mode since the UEFI won't have to load the RAID driver. But I haven't verified if this is noticeable.
That may depend on the system (hardware and drivers).
On my Dell Latitude e6230, repeated CrystalDiskMark speed tests on my 500GB Evo 860 done before switching from RAID, in AHCI mode (default MS driver), and after switching back to RAID showed:
Sequential read/write speeds 0.4%/1.3% slower in RAID mode
Random 512KB read/write speeds 0.3%/0.3% slower in RAID mode
These differences are within measurement error, since individual runs in a given mode varied by much more than that.
However, when it came to 4KB random read/writes, things were reversed
for QD=1, the RAID mode was 8.3%/4.5% faster
For QD=32, the RAID mode was 3.6%/12% faster
Most of those figures are larger than the min/max difference between runs within a given mode, which suggests the RAID mode may have some small edge over the AHCI one (possibly driver-related), though it could still be down to chance.
So, unless there's some other need to switch, it may not be worth bothering, and if small performance gains are of interest, it's probably worth doing before/after tests with one or more piece of benchmarking software.
If doing that, it's probably worth leaving things to quieten down for a while before benchmarking, as for some reason, after the switch to and back from AHCI, various system processes (search indexing, etc) seemed to dribble along in the background making disk accesses for some time before the system got nicely idle.