Re: e-clerk computer

["David R. Karger" <karger@theory.lcs.mit.edu>]

Only issue I wonder about: should we bother with raid, backup, etc on
our machine or should we "outsource", using a drive on the network
somewhere that already gets backed up by sysadmins?

   Date: Tue, 13 May 2003 16:22:30 -0400 (EDT)
   From: Jonathan Wolfe <jwolfe@graphics.lcs.mit.edu>
   cc: sfc@graphics.lcs.mit.edu
   X-SBPass: Local Origin

   Just met with Adel, here's suggested machine stats and our conclusions:

   Dual 2.8GHz Dell Workstation
   2GB RAM
   No Monitor
   ATI Radeon 32MB VGA video card
   146GB Ultra 320 SCSI Harddrive
   No installed OS (Adel says we can install what we want)
   48X cd-rom
   Integrated U320 SCSI controller

   approximate price - somewhere in between $4k and $5k (Dell won't give me a 
   web site price without an OS, I'll have to call them later).

   For a set amount of money to spend, it would most likely be more 
   beneficial to get a 2-proc machine with faster processors than a 4-proc 
   machine with slower processors.  However, it is, of course, always better 
   to have more computation power.

   Therefore (based on prices of Dell machines below), it makes sense to buy 
   a powerful 2-proc machine - the least powerful 4-proc machine is over 2.5 
   times more expensive than the 2-proc machine.

   Dual Xeon 3.0GHz (512K cache) - ~$6k
   Quad Xeon 1.5GHz (1MB cache)  - ~$15.7k
   Quad Xeon 1.9GHz (1MB cache)  - ~$19.9k
   Quad Xeon 2.0GHz (2MB cache)  - ~$28.8k

   One question:

   I don't see any need for gigabit ethernet on this machine, it seems that 
   the built-in 100MB ethernet would be sufficient.  Is there any part of the 
   design that I might be missing here?

   A few random notes as well:

   With Linux, you can't bind processes to CPUs, you just have to put up with 
   what the Unix scheduler assigns.  Linux kernels certainly support multiple 
   processors just fine, you just can't bind to a single processor.

   More than 2GB RAM probably isn't worth it, but if we ever need more 
   memory, it's not that expensive to get more.

   We should use the USB interface for the scanner and not the SCSI as it 
   will simplify having SCSI hard disks.  We can always put another 
   controller in the box to use the SCSI scanner interface if USB turns out 
   to be a bottleneck.

   Regarding RAID, even without hardware RAID we could choose to use software 
   RAID and 2 hard disks, although that would slow down writes a little.  
   Alternatively, without RAID we could just depend on disk backups.

   -Jon