Curious behavior with hard disks from Toshiba 4TB SATA MD04ACA400


Dream Large, Live Larger
Nov 4, 2015
Hi at all,

i running into some strange behavior with those drives.
First i thought it is the controller , changed it , changed the system , used AHCI SATA Intel chipset ports.
On every system/combination the same issue.


The drive D has the problem that i cannot enable the write cache of the device itself.

the second drive has no problem with enabling or disabling it. so i benchmarked drive E with both settings.

the bench in the middle show with activated write cache , the right one without.

so the behavior is similar to the left benchmark (drive D).

i checked the PCB of both drives , the look absolutely identical.

The Firmware are also the same on all drive. i have 7 of those drive with this issue and 3 without.
one of the "defective" drives is 9 days old, the other one has run already 510 day but Harddisk Sentinel says 100% excellent status on both drive.

i tryed also to switch the PCBs, but the drives won't came up in the device manager.

have anyone of you run into same issues ?

any ideas ?

Thanks all in forward.