I agree with the below. That you probably won't be able to take advantage of more than one CPU. Except maybe to off load some OS tasks. But you should not assume that a 1.4 GHz CPU will be faster than at 900 MHz CPU.
If the 1.4GHz CPU is a Pentium IV and the 900 MHz CPU is a Pentium 3 Xeon. You very well may see better before on the Xeon based system. Not only because of the CPU (which has extra cache) but because of the memory architecture of higher end systems. Note, I don't know enough about the specifics of how MySQL performs on Pentium 4s vs. Xeon's guarantee which will be faster. And it depends a lot on the rest of the hardward (disk drives, controllers, memory, memory controllers, cache, etc). And also on your specific transaction load. Christopher Thompson wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > At 03:44 PM 1/18/2002 -0500, you wrote: > > >>We use mysql heavily in production with tables over 30GB. We are going >>to purchase a new db server soon and the decision to be made now is >>whether we should go with a 4 cpu 700-900MHz system or a 2 cpu 1.4GHz+ >>system. Most of the time there is only one connection to this large >>database doing large queries including joins. What I am trying to find >>out is when (and how well) extra CPUs could speed up SQL operations when >>there is only one client/connection. In the opinion of those who know, >>which system would best serve our needs? The four slower processors, or the >>two faster processors? Why? >> > > From the user manual: > > 9.3.1 MySQL Threads > > The MySQL server creates the following threads: > > * The TCP/IP connection thread handles all connection requests and > creates a new dedicated thread to handle the authentication and and SQL > query processing for each connection. > * On Windows NT there is a named pipe handler thread that does the > same work as the TCP/IP connection thread on named pipe connect requests. > * The signal thread handles all signals. This thread also normally > handles alarms and calls process_alarm() to force timeouts on connections > that have been idle too long. > * If mysqld is compiled with -DUSE_ALARM_THREAD, a dedicated thread > that handles alarms is created. This is only used on some systems where > there are problems with sigwait() or if one wants to use the thr_alarm() > code in ones application without a dedicated signal handling thread. > * If one uses the --flush_time=# option, a dedicated thread is created > to flush all tables at the given interval. > * Every connection has its own thread. > * Every different table on which one uses INSERT DELAYED gets its own > thread. > * If you use --master-host, a slave replication thread will be started > to read and apply updates from the master. > > mysqladmin processlist only shows the connection, INSERT DELAYED, and > replication threads. > > > > As you are looking at having only one connection, I would say it is likely > that 2 1.4 Ghz CPUs will give you better results than 4 900 Mhz CPUs, all > other things being equal. Also, remember that operating systems don't > scale linearly in the best of cases, though Linux scales well up to 4 CPUs. > > Someone more knowledgable than I will speak up, I'm sure, but I'd focus on > dual CPUs with more memory rather than going for a 4 CPU machine. Also, > high speed disks would be nice, too. In fact, I'd say more likely you'll > see more performance with ONE CPU with more memory and faster drives than > you would with a 4 CPU machine limited in RAM and hard drive speed. > > > -----BEGIN PGP SIGNATURE----- > Version: PGP Personal Security 7.0.3 > > iQA/AwUBPEiLrgAttZAy2w6WEQIYKgCghq00GE1/2TXOguN6FkxacH9gumMAn0Vi > eUcuISI6S/W/h0KtvDeAliuy > =gmoV > -----END PGP SIGNATURE----- > > > --------------------------------------------------------------------- > Before posting, please check: > http://www.mysql.com/manual.php (the manual) > http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
