On Fri, 23 Mar 2007, Stephan Wiesand wrote: > On Fri, 23 Mar 2007, Brett Viren wrote: > > > Johan Mares <[EMAIL PROTECTED]> writes: > > > >> If you have dual core 64 bits processors in your server. Is it > >> recommended to install x86-64 version of a linux distro like SL ? > >> What are the benefits ? Are there any disadvantages ? It would be for > >> a LAMP, so would Apache or MySQL perform better or wouldn't they make > >> no use of it ? > >> Does anyone have any experience with this ? > > > > 32 bits: more software available, typically proprietary in nature. > > Which often runs just as fine under the 64bit OS. > > > Can access only <4GB RAM. > > That's a common misconception. There's a per-process limit of 3 GB with > the standard kernel. But the system can have and use more memory. Even > 32-bit SL3 can handle at least 16GB with the ordinary -smp kernel. > > > 64 bits: ~20% faster floating point (AMD only I believe), can access > > Typically 20% faster for many scientific applications, with few > exceptions. A bit more than 20% with AMD CPUs. Not limited to floating > point processing. > > IIRC, MySQL is one of those that do benefit but not that much. OpenSSL may > be anything from slightly slower to much much (several times!) faster, > depending on cipher and task. No clue how apache behaves. > > 3GB per-process address space limit for 32-bit apps on SL3, 4GB on SL4. > No (serious) such limit for 64-bit apps. > > > more RAM than you can afford. Potential compilation problems of > > legacy code. > > Usually, serious compilation and runtime problems of bad code, legacy or > not. > > Larger memory footprint, depending on application and payload.
It is common for large databases that use lots of memory to use 64 bit . It make the memory usage of the program faster and easier. -Connie Sieh > > > The last two probably don't apply to a LAMP. I'd personally go for x86-64. > > > Regards, > Stephan > >
