[CentOS] new ssd to play with

Wed Sep 7 21:11:05 UTC 2011
Les Mikesell <lesmikesell at gmail.com>

On Wed, Sep 7, 2011 at 3:55 PM, Jerry Geis <geisj at pagestation.com> wrote:
>  I grabbed a new SSD  M4-CT064M4SSD2 from Crucial.
> I am disappointed.  I stuck the unit in an Atom machine (zotac) with
> CentOS 6 on the disk.
> It really doesn't "feel" faster than the previous 5400 RPM drive that
> was in it.
> The SSD is giving me (in the zotac running centos 6):
> hdparm -t /dev/sda
> /dev/sda:
>  Timing buffered disk reads:  298 MB in  3.00 seconds =  99.30 MB/sec
> The Samsung 5400 RPM disk (in the zotac running Centos 6):
>  hdparm -t /dev/sda
> /dev/sda:
>  Timing buffered disk reads:  196 MB in  3.01 seconds =  65.02 MB/sec
> I'm not supper impressed at all. Sure the numbers say its "slightly"
> better but I don't "feel" it.
> I was expecting like really noticeable change in application load time or
> something - but not really.
> Just wondering...  Is there something that has to be done to take
> advantage of the SSD performance?

The point of an SSD isn't the transfer time when reading sequentially
ordered sectors, it is that you don't have to wait 8msec/track every
time the head has to move and wait for the disk to spin around to the
sector you want when that doesn't immediately follow the last one.
The OS makes a great effort to cache everything and avoid the delays
so you may not notice a big difference except the first time you load
something new.

  Les Mikesell
   lesmikesell at gmail.com