[SATLUG] Ubuntu x86 vs x86_64 Performance

[Phil Carinhas]

On Thu, Feb 01, 2007 at 11:33:40PM -0600, Daniel J. Givens wrote:
> I am amazed at what I have recently found. I wish I had hard numbers on this,
> but Ubuntu performs remarkably better as x86 than x86_64. Same system, same
> specs and everything is better. Memory utilization for the same applications is
> incredibly lower. The Nvidia drivers render smoother AIGLX graphics. VMWare runs
> smoother. I really feel silly for using x86_64 for at least six months now.
 
  64bit gives you greater capacity for file systems/sizes, larger memory & io
paths, but it comes at a performance price: more memory will be allocated to
accommodate this extra capacity, and io paths for apps take up more juice too.
So its very common to see performance slowdown for 64bit systems. If your
application is inherently 64bit though it could show a bit boost, but that
isn't the everyday situation.

  We do system porting from 32 to 64, and its very important to do cpu, io, mem, 
and network tuning to get the new systems to perform better than they did
before out of the box. You do get more access to a larger memory address space
and IO address space by far.

 So unless you really need that 64bit goodness, you might want to stick to 32 bit.
 YMMV,

-Phil Carinhas

-- 
 .--------------------------------------------------------.
 | Dr. Philip A. Carinhas      || http://fortuitous.com   | 
 | Fortuitous Technologies Inc || Tel : 1-512-351-7783    | 
 | Performance, Capacity, Linux & Unix Engineering Svcs   |
 `--------------------------------------------------------'