Re: Memory Sizing Advice

From: Mladen Gogala <>
Date: 09 May 2008 13:39:30 GMT
Message-ID: <48245412$0$6433$>

On Fri, 09 May 2008 15:05:42 +0200, Arne Ortlinghaus wrote:

> Unfortunately the Windows 64bit Operating System does seem not to make
> always the best usage of the additional memory: We see many page faults
> in the processes. But nevertheless I would say: after having a
> multiprocessor CPU the most important part is the quantity of main
> memory.

This is the standard fallacy that has resulted in many heavily messed up data centers. It's the I/O capacity and architecture that counts the most when it comes to databases. Machine with weaker CPU, smaller memory and good I/O capacity will usually beat overclocked monsters with 32GB or more of main memory hands down. IBM p5 560 will run circles around Dell machines with more raw CPU power and memory then the modest little 560. And it isn't that expensive, it starts around 50k. Stability and efficiency of AIX 5.3 is something that both Linux and Windows can only dream about.
I've seen 560 seamlessly performing 30,000 I/O requests per second and I've seen Dell380's choking up with 10,000 I/O requests per second. Databases are all about I/O. You need a machine to find generate reports from your database, not a machine to answer the question of life, universe and everything. That has been answered already.

Mladen Gogala
Received on Fri May 09 2008 - 08:39:30 CDT

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