dual vs single core opteron 100's
lars.tunkrans at bredband.net
Tue Jan 24 11:08:28 PST 2006
Ken Gunderson wrote:
>On Tue, 24 Jan 2006 19:09:22 +0100
>Lars Tunkrans <lars.tunkrans at bredband.net> wrote:
>>Ken Gunderson wrote:
>>>I was getting into a discussion the other day about this and decided to
>>>see what the FBSD amd64 gurus had to say about it. Given approximately
>>>equal cost of, for example, a single core Opteron150 (2.4GHz) and a
>>>dual core Opteron165 (1.8GHz) under what kind of situations would
>>>one be preferred over the other?
>>The DUAL core will be prefferd for Webservers, Application servers,
>>that are multithreaded and transaction oriented.
>That was his point- precious few of these exist in FOSS, e.g. X,
>anything Python based, etc. I thought, even so, the dual cores will
>benefit at higher concurrency (just not quite as good a dual CPU).
>Then enter his comment that "context switching on FBSD sucks..
>Blah, blah, blah..."
Really ? your friend should know that when you deploy
you always start several instance of the httpd servers. Even if
individually where completly singel threaded, starting the normal 5 to
on a dualcore would double the throughput, ( not the performance )
compared to a single core CPU,
provided you dont have other bottlenecks in the architecure, like too
few diskdrives, aso.
And provided that you get enough http requests to use the added
Context switching will take the same time per-proccess regardless of the
number of CPU's
Remember that additional CPU's dont imply that things work faster.
Only that you can
do more OF THEM concurrently. Throughput increases, not individual
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