I am currently looking at the feasibilty of using ssd-drives to reduce the runtime of an application with high disk-io.So far, I done some priliminary tests using dd and hdparam on my desktop ( i5-6600k with z170pro and samsung 850 evo with ext4) When compared to a mechanical drive, the numbers look quite promising.dd bs=1M count=1024 if=/dev/zero of=tempfile1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 2.09036 s, 514 MB/sdd bs=1M count=1024 if=tempfile of=/dev/null1024+0 records in1024+0 records out1073741824 bytes (1.1 GB, 1.0 GiB) copied, 1.97823 s, 543 MB/sThe results from hdparm are almost the same.If I were to thrown in another ssd to the mix in raid-0 configuration, can I expect an increase in performance by a factor of 2? Are there in ext4 specific gotchas that I should be keeping in mind? 
SSD Raid-0 Performance with ext4
linux;raid;mdadm