Did the AS SSD test show any red text in the upper left hand corner of its display directly above the capacity of the drive? You don't need to run the test itself to check this, just start the AS SSD program.
That would indicate a misaligned SSD, which will have very poor write performance. You would also see if the SATA controller is in AHCI mode, you would see "BAD" in the display.
What is showing the response time as 4000ms average?