<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> John Lucas wrote: <blockquote cite="mid200705300705.21188.MrJohnLucas@gmail.com" type="cite"> <pre wrap="">On Tuesday 29 May 2007 22:29, Les Mikesell wrote: </pre> <blockquote type="cite"> <pre wrap="">john wrote: </pre> <blockquote type="cite"> <pre wrap="">Why does disk speed matter so much? Aren't most operations on a file server fairly small scale i/o once or twice a session i.e. opening a saved document, and writing a saved document.? </pre> </blockquote> <pre wrap="">The problem on a multi user machine is that every user wants the disk head to be in a different place at the same time so seek time is often more important than transfer rates. Consider what happens when everyone is using a browser and every page and image each user loads is being cached in their home directories. Scsi disks/controllers can typically take a bunch of commands at once and queue them up while IDE and most SATA's can only do one comand at a time, waiting for CPU intervention at each step. </pre> </blockquote> <pre wrap=""> The behavior ("Scsi disks/controllers can typically take a bunch of commands at once and queue them up..."), is known as "elevator seeking" and is a huge advantage of SCSI over SATA. </pre> </blockquote> I'd agree with the above; SCSI, if you can afford it, is always better. However, if cost constraints are an issue (and I've seen plenty of situations in which that's the case), I've actually used PATA for a 25-student lab. Yes, EIDE. One disk. And nobody complained. Granted, it was an update from the Windows 98 that they were using, on Dell Optiplex GX1's, so the speed increase by going with K12LTSP was heartily welcomed, but if things were "slow", I would've heard about it (it's a Microsoft shop). Therefore, I'd suspect that a hardware RAID using SATA would be just fine for 35 students. --TP <div class="moz-signature"> _______________________________ Do you GNU!? <a href="http://www.gnu.org/">Microsoft Free since 2003</a>--the ultimate antivirus protection! </div> </body> </html>