Re: speed performances / hardware / cpu
antoine wrote:
Hello,
I'm developing / supporting a java "client" application (running on PCs
with XP pro, jre 1.5) which is a high performance trading client. it
receives market updates, displays them on screen (swing), does a serie
of computation, and performs several actions based on computated values
(order sending, cancelation, etc...). it is designed to run for 8 hours
straight without interruption, does not access any database, only uses
socket-based I/O, and is correctly multi-threaded.
I'm looking at upgrading our workstations, to hopefully get a speed
increase. currently, our "base computation" routine takes around 5ms
average, and I'm looking at reducing this number (I'm also looking at
improving CODE performances, but this post is about hardware).
currently we're running on dual CPU intel Xeon 2.8GHz, roughly 3 years
old, with 1GB RAM. virtual memory usage is around 128MB, so I believe
RAM is not an issue.
which kind of upgrade would sound smart to you ? I've seen technologies
like:
- all the "dual core" family
- 64-bit architecture (although no JVM for intel on XP pro 64-bit)
- simply pushing the frequency to 3.6GHz...
does 64-bit make sense ? or is it only for memory intensive application
(we're more concerned with execution speed) ?
any insight or link to any informative page would be most welcome !
Not to be unduly harsh, but all these upgrades would be
STUPID! -- until you've measured what's happening on the current
hardware. You've already made a start by measuring the memory
usage, and that's good. Now measure the other components that
you might upgrade: How much CPU are you using, how much time do
you spend waiting for disk I/O, are you drowning in cache misses,
and so on and so on. If the real problem is (for example) a
network transaction, making the client machine faster just makes
it wait faster.
Continue as you have begun: Measure the consumption of the
different resources, and try to determine what is holding you
back. From your description there's an excellent chance that the
scarce resource is in fact CPU power -- but won't you feel silly
(and impoverished) if you spend a lot of money upgrading the CPUs
only to discover that the real bottleneck was the El Cheapo
graphics card?
Carpenters have a motto: "Measure twice, cut once." For some
reason, computerfolk seem resistant to that wisdom. Buck the trend,
and spend your money ("cut") only after you've measured. Be a
carpenter!
--
Eric Sosman
esosman@acm-dot-org.invalid