Re: new harddrive degraded speed

[Dan Ritter <dsr@randomstring.org>]

brainfart@posteo.net wrote: 
> 
> 6tb drive at 3.0 gbs
>  root@hc4:~# hdparm -t /dev/sda
> 
> /dev/sda:
>  Timing buffered disk reads: 406 MB in  3.01 seconds = 134.83 MB/sec
> 
> 
> 2tb drive at 6.0 gbs
> root@hc4:~# hdparm -t /dev/sdb
> 
> /dev/sdb:
>  Timing buffered disk reads: 436 MB in  3.00 seconds = 145.27 MB/sec

Both of these are substantially under 3Gb/s. The fact is, not
only do different spinning disks read and write data at
different rates, the rates change across the same disk.

For what it's worth, the WD Red 6TB disk you've got is a
notoriously slow drive, for a CMR. It has a fairly high latency
and runs at 5700RPM. It's entirely likely that your 2TB disk is
actually faster.

You're not likely to notice the 10MB/s difference in actual
usage, though. It will be dominated by seek times for
interactive usage, and humans are bad at paying attention to
longer times without a clock in front of them.

-dsr-