I plan on using SSD storage for frequently accessed data (OS and apps) in my next build and was wondering if it's worth getting 2 SSDs, putting them in hardware RAID0, then doing a soft RAID1 with an identically sized storage drive partition for redundancy. I don't do a lot of writing so the writing performance shouldn't be too much of an issue, and the reading shouldn't be slowed due to most random access data being pulled off the SSDs quickly. Am I correct to assume this sort of performance? Or is this a useless idea?
First of all I don't think you can assume that all the reads will go to the SSD. In a RAID-1 configuration a "dumb" RAID controller will simply round-robin the I/O requests to alternating drives, and a "smart" RAID controller will direct I/O requests to the device whose heads are closest to the desired data (i.e., whose last I/O request was to the closest LBN). In either case you can probably expect about 50% of the I/Os to go to the hard drives, in which case you'll actually be killing the performance of the SSDs.
Secondly, RAID-1 is not a backup. It doesn't protect against theft of the computer, corruption, power hits, etc. RAID-1 protects only against media failure, and SSDs are probably less likely to suffer a failure because they have no mechanical parts. Since you need an external backup anyway, you're better off to use those hard drives for that purpose rather than for RAID redundancy.
TY for the advice;
Could you recommend a piece of free software I could use to run regular backups of the SSD drives on an extra HDD? The reason I considered soft RAID 1 is because it is very seamless at the end of the day...