32 bit distro or 64?

[Matt Kettler]

Paul Hutchings wrote:
> Again probably not a MailScanner specific query but as this box is
> specifically to run MailScanner I’ll ask here.
> 
>  
> 
> I have a new DL360 G5 and I’m planning on installing OpenSuse 10.2. 
> Should I be using the 32 bit or 64 bit with regards to MailScanner,
> basically are there any reasons to choose one over the other?
> 

I've not benchmarked it, but theoretically the difference should be insignificant.

On the up-side the 64bit version will use native 64bit math instructions for
64-bit arithmetic (ie: file offsets), making common additions take 1 instruction
cycle instead of 2. However, this isn't so common, particularly in a
MailScanner/SA/AV setup, that it would make a big difference.

The downside 64bit version will also use 64-bit pointers and code segments,
increasing memory usage slightly. However, this isn't big enough to make a
significant difference either. You've almost certainly increased memory usage by
less than 5%, and probably less than 1%.

However, if you ever expect to "scale up" the memory beyond 4gb, the 64-bit
version would be helpful. Otherwise, it's a wash. You gain a small amount of
performance for a small increase in memory use.