WD7502AAEX-00Y9A0 (750GB Caviar Black) slow read speed?


HD Tune Pro reports the drive supports UDMA Mode 6, but that UDMA Mode 5 is active. Speccy reports the drive using SATA II, while it should be using SATA III. I doublechecked the drive is connected to a SATA III port on the motherboard. In BIOS it reads 6.0Gb/s, and SATA was set to IDE mode (now AHCI, no difference in HD Tune results).

- Are the above figures normal for that drive? (min 40MB/s, max 98MB/s, avg 75MB/s)

- How do I enable SATA III ?

- Is it true that some Caviar Blacks have faulty firmware (just something I heard)? If so, which drives exactly? Is there a fix?

OS: Win 7 Ultimate 32-bit

Mobo: Asus P8H67

The Caviar black top sustained transfer speed is 128MB/s, however you need to have a top computer in order to get that speed, 75MB/s is the standard speed for regular computer. What’s your computer configuration.

CPU: i5-2500k (quadcore)

GPU: GTX 460

Mobo: Asus P8H67

RAM: 2x 1GB Kingston sticks 1333mhz

I have this problem too. My WD7502AAEX-00Y9A0 average spped is 76MB/s . AMD SATA controller detect my disk as SATA 1.5G and Marvell 9128 regulary as SATA3.  Can i fix anyway this problem ?

my specs:

AMD Phenom X4 965BE

Gigabyte 790XTA-UD4

2x2GB A-DATA XtremeSeries

Asus 5850 DirectCU

Seasonic 620W

My seagate for data reach speed about 120MB/s

My caviar black for system only 76MB/s …

I have this problem too. My WD7502AAEX-00Y9A average spped is 78MB/s .  moy_hd.JPG

my specs:

giga p35-ds4


My WD5000AAKX-001CA0 blue  for data reach speed about 122MB/s

My caviar black for system only 78MB/s …


I have this problem too. Have any solution?


cpu: i7-2600k

Curious, my drive seems slow as dirt sometimes as well.  If I go into HD Tune, or Passmark Disk Checkup, my buffer reports as 0 KB or N/A.  My other drives report correctly.  Can anyone else confirm this is just a software issue or possibly my logic board is failing?

Same problem here. Found this article:


Might be platter density.