WDC WD15EARS-00Z5B1 awful performance

I have 4 of these drives and I have had nothing but problems with them in a NAS, raid5 volume read/write performance was appauling, volume crashed. 

The above is software (Linux) raid so it is theoretically fine to use non raid/enterprise drives as they don’t get booted out of the volume as quick as hardware raid does if the drive fails to respond.

Split up the drives, reformatted, and now in Windows7 trying to get data on to one of them is up-down-up-down-freeze-up-down… averaging 16MB/s, random freezing, occasional speed increase to 25MB/s… transfer started out fine at 60MB/s.

Source files are on a 200GB SATA HDD via onboard SATA1
Destination drive is on same controller @ SATA3

I get a steady 45MB/S copy speed with other drives on SATA0 and SATA4 of same controller with SATA1 source and between any other combination apart from the WD drive, so its not my 200GB drive or the controller.

I asked WD for a test tool and they told me they dont have one for Windows 7.  Well thank **bleep** that 7 ships with VM-XP then eh WD?

I also tried copying files off of external 500GB WD drive via usb and found it also takes forever, slowing down to under 1MB/s…when traget is the 1.5TB WD drive.

Once I have a full copy of this data on the WD drive I will test the other 3 WD drives on my PC to see if it is common across all or not.