Half Write speed in SSD

[fw1374]

Hello to all,

I get Transcend SSD320 256 GB a few days ago. Naturally I run some tests. In ATTO I get abnormal write speeds. Read speed is very close to advertised speed (560 MB/s), but write speed is almost half of expected speeds:

http://img199.imageshack.us/img199/600/attossd.jpg

Before any answers things I have checked or done:

-My OS is Windows 7 (Clean Install)
-SSD is connected to Intel Sata 3.0 controller in Sata_0, not Marvel or another controller. (Gigabyte GA-Z68AP-D3)
-AHCI was always enabled
-I tried both Microsoft and Intel drivers (Msahci- IaStor)
-My firmware is latest (5.0.4), checked this from Transcend's website and SSD Scope program.
-TRIM was always enabled, also checked this with Intel's SSD Toolbox and cmd from Windows.
-Write Caching is enabled.

What could be the problem?
Any help is appreciated, thanks.

 

[kbp]

Have you run a W.E.I by chance and rebooted?

 

[fw1374]

I did it. I get a score 7.9 for primary disc.

I also changed SATA cable, moved to Sata_1 from Sata_0, checked alignment with Paragon Alignmen Tool 3.0, optimally aligned according to program.

Results are fine until 64.0 test, there SSD almost reaches 500 MB/s, but after that write speed gets down almost to Sata 2.0 levels.

 

[kbp]

Try running AS SSD. . . Google it to download.
And post results

 

[fw1374]

@kbp

Thanks for your effort.

I kinda solved the problem. I have another build with FX 8350 and 990FX chipset. I installed Windows on SSD on this system. Results are not better but consistent (I only tested once with Microsoft's driver):

http://img703.imageshack.us/img703/3848/attossdamd.jpg

I think it has something to do with my motherboard's controller (ga-z68ap-d3) not SSD.