I think performance wise, your best bet is to try both and benchmark, and share the results here for everyone to see! I would suggest using the ATTO Disk Benchmark utility.
As far as which I'd choose, I hate "fake raid". Always caused me more problems than it prevented. Get a real RAID controller or do software RAID. The only reason software RAID wasn't very popular in the past is because of performance issues, but that's a thing of the past.
I convert my comment to an answer, as the comment by @C0D3M0NK3Y confirms it.
Windows will not accept dynamic virtual disks in a RAID, but the comment by @C0D3M0NK3Y confirms that fixed-size disks used to work in XP Professional. There is therefore an excellent chance that fixed-size virtual disks will still work with RAID in Windows 7.
It is actually quite logical that Windows cannot create a RAID over dynamic disks whose size is unknown and can change at any moment.
EDIT/ADD:
Had to try it to see either way for sure, and it works (when using fixed-sized VHDs):
Host OS: Windows 7 Ultimate, with two "Basic" disks.
VM OS: Vista Ultimate.
Created two "fixed sized" VHD's of 500MB each, one on each of the host's physical disks, and attached them to the VM (as the 2nd and 3rd drives).
Initialized the new disks in the VM and then converted them to "Dynamic" disks (in Vista's Disk Management).
Then joined them together into a RAID0 (stripe):
Worked like a charm, without any need to do anything 'weird'.
Best Answer
Looks like this setup is quite ok. The basic rule is to use
mdadm
with--write-mostly
parameter so that writes go to HDD. Reading will still be done from fast SSD. Also, the--write-behind
parameter is said to improve write performance.Support for TRIM command in such a setup appears to be a problem, though.
Further keywords for searching:
linux ssd raid hybrid
mdadm "--write-mostly" ssd
Further links: