Just bought Team XS2 ssd which tells that is should have 550mb/s read and 500mb/s write. I'm only getting this:

Something seems to be wrong. There is a chance that this drive is a junk, but I hope that I did something wrong.
System:
- OS: W7x64
- CPU: 7 2600
- Memory: 8GB DDR3 (1833 MHz)
- SSD:120GB (split into 2 partitions)
- Board: p8z68-v
An interesting thing I noticed: I changed one of the options. Everything works fine, speed is near 500MB/s.Is this normal behavior?
