What gives better db performance, more memory or add'l processor

[Debbie Fleith]

We are replacing an HP-UX server with a i386 Linux server and was wondering if someone could tell me what they would recommend for a small database server (18 users) running RH5.

4GB memory / single 1066MHz Xeon Processor
OR
2GB memory / dual 1066MHz Xeon Processors

[Jeeshan]

better you can check the benchmark test result for your query

http://h18004.www1.hp.com/products/servers/benchmarks/

[TwoProc]

Seriously, I wouldn't even consider bringing up an Oracle instance with 2GB memory, or with a single processor on a server.

So, the answer is neither.

Go with 8GB Memory and dual Xeon Processors.

[Steven Schweda]

> What gives better db performance, more
> memory or add'l processor

That rather depends on whether the system is
CPU-bound or out of memory. You might be
wise to see why the HP-UX system is too slow
(assuming that that's why you plan to move
away from it). How much memory does the
HP-UX system have? Does _it_ need more? Is
its CPU max'ed out? I don't do perfomance
analysis on HP-UX, so I know nothing, but I'd
bet that there is a big toolkit somewhere for
just that purpose.

You can either find the existing bottleneck,
or you can guess, or you can just throw
hardware at the problem to see if anything
helps. How big is your budget?

[Debbie Fleith]

This new server is for a very small scale Progress database (3 GB in size). There are no performance issues on the current server to evaluate, and it is obsolete. The budget can support either option, not anything extra, so I was wanting to know which in general would give more bang for the h/w buck. Sounds like it is not a cut and dry question, but, since memory is easy to add later, I'm thinking the extra processor might be the way to order this system?

[Ivan Ferreira · Accepted solution]

Normally, unless your current system is cpu bound, your database will be happy if you have more memory. But this really depends of the transaction type.

The processor probably would be dual core o hipertheading enabled.

[Steven Schweda]

> There are no performance issues on the
> current server [...]

Well, that explains why you'd want to replace
it.

> [...] it is obsolete.

Where "obsolete" = "working fine"?

> [...] How much memory does the HP-UX
> system have? Does _it_ need more? [...]

Assuming that "issues" and "problems" are
similar, then, apparently, however much
memory it has is probably enough. Why
didn't I think to ask how much that was? No,
wait. I did. Still wondering, then.

[Debbie Fleith]

Thank-you Ivan -- that's the generic response I was looking for.

For all of those "wondering" -- the current system has only 512 MB of memory, not having real performance issues, but, its on un-supported OS and unsupported hardware-- so we are replacing it. You obviously can't even buy a server with 512 MB these days and the extra 2GB memory or extra processor cost about the same. So, I just wondered which one is best to run a small database? I'm trying to get this customer the best configuration that their budget can buy, since today's h/w dollars can buy so much more.

[Steven Schweda]

> [...] the current system has only 512 MB of
> memory, not having real performance issues
> [...]

Knowing nothing, I'd guess that if 512MB was
enough before, then 2GB would probably be
enough now, and the other CPU probably
couldn't hurt. Of course, if the old CPU
wasn't being kept busy, then adding a second
(presumably faster) one probably wouldn't
help any more than adding additional memory
which won't get used, either.