Brand new VelociRaptor : 3.5MB/s write speed. WTF?

Hi,

last week i bought a new VelociRaptor (WD3000HLFS) and I have some serious issues with it. Reading seems to be pretty fast (>60MB/s) but writing sometimes just slows down to 1-2MB/s. After a veeery long Win 7 x64 setup (>1h) and two f...d up Vista x64 setups (could not format/could not decompress) I've tested it with HD Tune and the graphs are pretty interesting. My question is if anyone has seen something like this:

In every test there is an empty region between 38% and 85%.


Other than that void anything else seems to be ok:


But the write tests are extremely poor:

Maximum 3.5 MB/s

Write access times in the tens of seconds:


S.M.A.R.T. : no errors:

and no errors found by the Data Lifeguard (WD Diagnostics) either.

I'm pretty sure I'll have to return the HDD, but maybe someone has seen a similar behavior and can point me in some other direction.
Could be important: the HDD is in the last SATA connector (bottom most on Intel mobo) the others are all taken (4 HDDs, all 7200 RPM, 2 SATA2 and 2 SATA1 and a DVD-WR). I will try to change the SATA cable, and the SATA port and post back the results.
Other than the mobo (Intel DX48BT2) the system setup i think is irrelevant.
Here's some info from HD tune Pro:


Thanks!

[edit]
that gap in HD Tune graphs seems to be there on every other hard drives in the comp (but from 57% to 100%) so it could be normal. Than the only problem I have is the incredibly slow write performance.

Try testing it on another computer. If the same thing happens, RMA the drive!