[K12OSN] SATA vs SCSI
Liam Marshall
lsrpm at mts.net
Tue Sep 21 00:51:52 UTC 2004
Chris Kacoroski wrote:
> Liam,
>
> I did several tests with SATA and SCSI and found out that the
> controller card is a limiting factor. The fundamental difference
> between the two technologies is that SCSI drives queue up the requests
> and the optimize the path of the r/w head across the disk. SATA do
> not have this ability so the r/w head wanders all over the disk
> handling the requests in a first come, first serve basis.
>
> What this means, is that if you are reading or writing one large file,
> SATA perform as good as SCSI (if they have the same spindle speed).
> If you have several different processes r/w to multiple files on disk,
> SCSI out performs SATA by a large margin. The new SATA standard out
> sometime next year is suppose to include queueing, but until then SCSI
> is definitely worth it for small installations like yours.
>
> If you have a large installation (e.g. 2TB+ of disk), you can use a
> device like the EonStor raid which connects SATA disks to a scsi
> controller and performs very well. I have one of these and plan to
> get another one for a different application. I tried 3ware cards, but
> they failed in my application (I still use them to mirror the system
> disks and they work great for that).
>
> cheers,
>
> ski
>
fair enough, I like the idea of scsi anyway, I don;t have a raid
controller for the scsi, but I have an Adaptec controller with two
connections, I forget off hand which model it is. It does the ultra 2
wide and the narrower type. In order to do Raid, of whatever flavour,
you need either a raid controller or 2 scsi cards, right? the one I
have is not a raid controller
I was thinking sata raid because the mb I am buying has a sata raid
controller on board
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