Vertex 4 write speed slow

[Vertigo]

The write speed on my Vertex 4 seems a bit on the slow side. Any ideas?

 

[Vertigo]

A couple of things to try.

1. Are you into the right sata ports on your board?
2. Is the drive running the latest firmware?
3. Is windows installed using the AHCI setting in the bios?

Yep, it's in the first 6Gbps port and Intel RST confirms it's running at this speed. It's on firmware 1.4 - I know there's a 1.5 but there shouldn't be much speed difference between them. Yep, on AHCI.

I read that performance drops once they get over 50% full.

Yeah I read that but it's only 35% full - fresh Windows install a few days ago.