I just would like to say, that performance improvement should be done on case-by-case basis:
- I know cases where increasing SGA could kill performance and not improve it;
- there are cases where application will be much slower in 64 bit mode vs 32 bit mode;
- details makes sence - for example, you can switch from DELL 2850 to AMD SUN server and sometimes see 10-times performance degradation justbecause SUN servers have RAID cache disabled by default while DELL servers have it enabled for write-back mode.

And so so on.

So you should find your bottleneck first, compare the size of this _neck_ on old and new server(s), and then decide how to
improve. For example, if your bottleneck is on the disk IO and if bigger SGA don't help (for example system makes full table scans and
table sizes are bigger then big oracle pool) then replacing servers can not help.


----- Original Message -----
From: Herman.Maseberg@(protected)
To: Alexei_Roudnev
Cc: Linux-Oracle
Sent: Tuesday, May 29, 2007 1:33 PM
Subject: Re: [suse-oracle] Bad performance on Proliant DL580 G4



"Alexei_Roudnev" <Alexei_Roudnev@(protected):

> Why did you expected better performance on 64 bit servers? It is not true;
Because RAM memory es almost double and then I can address more SGA increasing cache hit ratios.

> 64 bit servers are often slowly vs 32 bits (because less data are in the
> same cache) and advantages comes from the bigger memory and better limits
> and not from the 64 bits alone.

And I suppose that in three years processor's technology get more powerfull.

> My own tests (I don't insist) shows that Xeon processors are slower in 64
> bit mode, and speculations exists that AMD processors are little faster in
> 64 bit mode. Anyway, difference is minor there.

In your opinion what is the way to achieve better performance, change servers and operating system to HP-UX or Solaris, or Windows may be?

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