wrote:
On Sunday, 18 December 2016 18:02:41 UTC+5:30, Lars Bonnesen wrote:
For at 4 TB drive sitting internally in a SuperMicro server as an
ESX-test-/develserver, would you prefer the newer Seagate ST4000NM0035 over
ST4000NM0033?

I can see that the newer one are having a slightly faster theoretically
internal speed, but otherwise they look quite the same. Are the newer ones
worth the price difference?

Regards, Lars.

Can we use both ST4000NM0033 and ST4000NM0035 in a RAID6, i.e
for example can we use 2 nos. ST4000NM0033 and 2 nos ST4000NM0035 ??

For RAID, it's preferable to have drives with TLER (time limited error recovery).
That helps prevent unnecessary array rebuilds due to the reallocation of
sectors.

TLER/CCTL

https://en.wikipedia.org/wiki/Error_recovery_control

Other than that, you could likely mix those two drives in RAID,
as the slowest characteristic determines the overall performance.
If one drive does 200MB/sec and the second drive does 210MB/sec,
the 200MB/sec drive defines the response. If one has a seek
time of 12ms and another drive has a seek time of 13ms, the
13ms drive determines the response of the array (for anything
which cannot be hidden by that particular RAID array type).

You also select drives rated for the vibration characteristic
of the application. If the disks are going in a rack mount
with a lot of other drives, an Enterprise drive might be
better for that than a Consumer drive. An Enterprise drive
with a piezo actuator at the head for fine positioning,
is supposed to track better when the drive receives vibration
from the drives next to it.

Those are all considerations when selecting drives for RAID.

Paul