Same problem here. I have a pretty old computer without AHCI, without trim function, SATA II with no controller BUT anyway I didnt compare my two Samsung EVO 1TB performance with other systems performances, but with another SSD I have in my computer, a 60 GB Mushkin Callisto DeLuxe.
I have to mention I applyed your advices in that order you mentioned for the Samsung SSDs.
1. CrystalDiskMark 3.0.3 x64
For Samsung EVO 1 TB....................................For Mushkin Callisto DeLuxe 60GB
READ (MB/s)...WRITE (MB/s)..............................READ (MB/s)...WRITE (MB/s)
Seq.........140.0......115.1.........................................168.1..........61.51
512k.......133.5......114.8.........................................165.5..........50.44
4k............32.35.......51.11........................................19.49..........48.69
4kQD32...39.25...72.78.............................................21.95..........41.63
so, some results are higher for the Mushkin, but the HUGE difference was with the second test:
2. Samsung Magician Performance Benchmark
.....................................For Samsung EVO 1 TB.................For Mushkin Callisto DeLuxe 60GB
Sequential read (MB/s)....................142................................................244
Sequential write (MB/s)....................116...............................................221
Random Read (IOPS).......................9583............................................6762
Random Write (IOPS).....................17820...........................................25840
Why are my results so bad and why Mushkin was superior despite the Performance Optimization of Samsung?
Any help/advice/suggestion would be highly appreciated.