Re: [squid-users] squid on 64 bit server: memory calculation differences with the FAQ?

On Tuesday 06 May 2003 19.17, Adam wrote:

> However the FAQ comment "more [RAM] on 64 bit servers such as
> Alpha" makes me wonder by what amount of "more" I should be
> calculating.

This is not known as no comparable measurements have been done on 64
bit platforms, but an estimate is that the memory requirements in
64bits is somewhere between 1.3 and 1.8 times the requirements for 32
bits.

> That is if 64 bit machines like the Solaris 8 Ultra 60 box I am
> running Squid on needed (hypothetically) 15 * total GB

I would probably recommend compiling Squid as a 32 bit application.

But at the same time there is a few gotchas in the Solaris 32 bit
environment which makes me doubt.. This doubt is not actually related
to the 64 bit question but Sun took the opportunity to get rid of a
lot of old legacy braindamage of their old 32bit API when they
designed the 64 bit API of Solaris, making Solaris a quite nicer and
cleaer operating system for applications running in 64 bits than
applications running in 32 bits. However, Squid is designed and
tested on 32 bits, and probably does not like 64 bits very well
(well.. that said I did run Squid fine on Alpha some years back with
only some small amount of patching required..) so in the end you
probably get new more problems than the problems fixed by using
64bits, in addition to the substantial increase in memory usage.

> Secondly, are there any advantages to running Squid in 64bit mode?

Probably none, and quite likely more problems as very few people have
used Squid in 64bit mode..

There is some small benefits in compiling Squid with support for 64
bit file I/O, but this should be considered highly experimental at
this time and not recommended for production use..

One notable benefit of compiling Suqid 64 bits would be if you need to
make a really big Squid. A Squid compiled for 64 bits should have no
problem with upper limit on memory usage if you can afford the
memory.

64bits is generally a waste except for applications needing more than
2GB of memory or certain specific applications who benefit from the
64 bit integer math improvements (most applications are quite happy
with 32 bit integer math).

Regards
Henrik

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