SSD 4K speed is very slow

I bought SSD Sandisk Extreme Pro. Tests 4k-32k show slow speed. My comp details: Motherboard GA-Z67-AP-D3 with the latest Firmware FD. Driver Intel(R) Desktop/Workstation/Server Express Chipset SATA AHCI Controller.

Windows 7 sp1 64 bit. Antivirus is not installed.
What kind of problem can it be? And are there any ways to solve it?

Test:

My request is closed. The problem turned out to be not in SDD.

Care to share what the issue was? It may help others as well. 

Yes, please! I have same problem, how to solve it?