Some thoughts on the performance of SSD RAID 0 arrays

Conclusions

In our tests, we compared the performance of a RAID 0 array with all possible stripe size configurations against the performance of a single SSD.
In sequential read and write tests, as well as in the random tests with 512 kiB blocks, using a RAID 0 array provided a considerable gain in performance compared to a single SSD, with a typical improvement around 80 percent, but reaching as much as 324 percent. Therefore, it is clear to us that instead of buying a single, large-capacity SSD, it is better to have two smaller-capacity models configured in RAID 0.
In the random test with 4 kiB blocks, however, the bandwidth has not improved with a RAID 0 array; this is probably because of latency issues on the RAID controller or on the controller chip in the SSDs we used.
Regarding to the stripe size, our tests have shown that, here, size does not really matter (at least with the testing methodology we used). In some tests, the best performance was achieved with larger stripe sizes, and in other tests smaller stripe sizes were faster. The only possible conclusion is that, if you work with large and compressible files (uncompressed video editing, for example), you may choose the 128 kiB stripe size configuration. If not, just use any intermediary value.
It is important to keep in mind, however, that the results can be different if you use other SSDs with different characteristics that the ones we used in our benchmarking.