Would running SSDs in RAID 0 do anything in terms of increased speed?

To start out, I have 2x 500 GB Samsung 850 Pro SSDs and I wanted to know if you could even get any extra performance out of them by running RAID 0.

It'll benchmark better. I have 4x 840 pro (256gb) and 2x 840 evo (1tb) raided on an LSI 3xxx controller with a bunch of DRAM cache in front of them.


Benchmarking better doesn't tell you anything about real-world performance that you can actually feel.

For some things you can notice an improvement - for example, if you frequently deal with multi gigabyte files. For example, if you start stop a database server with 20 gb of data then you'll be able to load it into system memory faster provided you're IO-bound and not compute limited. You might save 5 seconds the first time you read the db. Does having twice the IO performance justify the cost in memory you had to pay for getting the disk? You'll have to work that out yourself.

On the other hand, some things are going to get slower. For example, if you optimize for the 'read mutli gigabyte files fast' use-case, then very small files like the ones that are likely to make up a git repository will read and write more slowly than even a single disk. You pay a penalty for having a RAID controller between you and the disk, and you get no performance gain unless a file spans at least two blocks on different disks. Likewise rebooting takes longer becuase you have to wait on the controller to initialize.

For every day use: playing some video games, browsing the web, booting a new OS, etc. you aren't going to notice a difference because you're never IO bound once you have an SSD. I could post videos of games loading from a single disk vs a 4-disk raid-0 set and you'd never be able to tell the difference. Likewise, loading from ram-disk is basically identical because you're rarely waiting on your disk once you can pull off 500mb/s

For most users, unless you've got a specific reason, raid doesn't make a lot of sense. If you need improved performance then PCIe SSDs are a better choice unless you don't have any PCIe slots to spare. For users who need space, a single large disk makes more sense.

If you have two disks laying around and need a single 1TB space, and have a good backup strategy, then sure: use RAID-0 or JBOD. For any other situation I'd not recommend it without a clear "I need raid-0 to do X". Unless that reason is good enough to give up a faster CPU, more memory, or better GPU then you should reconsider.

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