Racks vs. pile of PCs

[Christopher B Comer]

Hello all,

I've been on the list for a number of years and I find this recent
discussion of extreme interest.  I have a background in Computer
Engineering and  working on a solution that would provide more use out of
 standard PC's box.  Cost per node will be much less.  I do have a
question that would help in my endeavors.  What CPU's are desired
(currently offered on market)  for Single and Double CPU systems and
associated chipset?  It would be also be helpful to know what CPU is
desired to be used in an upgrade under a budgetary constraint?  In other
words what CPU would be purchased with minimum amount of money to spend? 
In the next 6 months is there a desire to expand in node count, and if so
how many (Please mention what CPU would be replaced or expanded from)?  
Thanks.  

On Sat, 17 Aug 2002 13:24:38 -0400 (EDT) Mark Hahn
<hahn at physics.mcmaster.ca> writes:
> > One advantage that comes to mind, although it may not be worth 
> $6000, is
> > when you have 20 PC's stacked, according to Murphy, the bottom one 
> will fail
> > first. The rack mounted version will be much easier to service a 
> failed unit
> > than the stack version.
> 
> wire shelving units cost very little and often have an option for 
> wheels.
> 
> I think the choice really boils down to the number of nodes you 
> want.
> chances are good that your floorspace is limited, therefore density
> is an issue.  we want O(150) CPUs and can only afford ~2 more racks 
> of floorspace in our machineroom, so we need roughly .5U per CPU.
> further, with more than, say, 64 CPUs, you have to think seriously
> about hardware failures.  that, in turn, biases you towards 
> higher-end
> hardware, since a generic ATX power supply is definitely not in the 
> same MTBF range as a good rackmount one.
> 
> still, Dell/Compaq all make small uniprocesor desktops; for 
> instance:
> 
> http://www.dell.com/us/en/biz/products/model_optix_optix_gx260.htm
> 
> 3.6*12.5*13.9=625.5 cuin, versus 19*21*1.75=698.25 cuin for 1U.
> wow, you can actually get 2.26GHz P4, 533MHz FSB, 512M ddr, 1000bT
> all for under $1k.  3-year warrantee.
> 
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