# 32 bit vs. 64 bit?

## c707176

Just a question for my understanding:

I have a new system with a brand new Intel Centrino 2 vPro which supports 64 bits. Is there any real advantage of using 64-bit gentoo? Or is it merely causing troubles?

----------

## Cyker

Don't mean to be rude, but there are a LOT of threads on this subject already.

Unless you have some specific query, you're better off reading those as they've flogged this question to death a long time ago  :Smile: 

----------

## c707176

Cyker, 

I read some of the most recent threads. However, my primary impression is that many of these threads are pretty inconclusive and it seems that people rather post their personal flavors than the hard facts (e.g. regarding performance, support, stability of the code).

So, I wondered if there are any "hard facts" around from people having experience on most recent archs  :Smile: 

----------

## zyko

 *Quote:*   

> Is there any real advantage of using 64-bit gentoo?

 

Only if:

1. you run some very specific software that uses 64bit technology (like e.g. numerical simulation for your engineering PhD studies).

2. you want to use 4GB of RAM or more. 

If you can safely say no to both scenarios, you can stay with good ole i686.

----------

## cyrillic

 *zyko wrote:*   

> 2. you want to use 4GB of RAM or more. 

 

Also worth noting :

That 4GB figure includes system RAM plus video card RAM plus any other memory mapped IO devices.

----------

## pappy_mcfae

 *c707176 wrote:*   

> Cyker, 
> 
> I read some of the most recent threads. However, my primary impression is that many of these threads are pretty inconclusive and it seems that people rather post their personal flavors than the hard facts (e.g. regarding performance, support, stability of the code).
> 
> So, I wondered if there are any "hard facts" around from people having experience on most recent archs 

 

Ok, the facts are source code is source code. Some is great, some sucks. I run an Core2 as ~amd64. I find that the system is as stable as the 32 bit systems. The only problem I've found over and above anything I've had with 32 bit systems is a bad 32 bit library broke Firefox for a day. Other than that, the system runs 24/7 without much trouble.

Performance is out of this world. I have no benchmarks to throw around. All I have is the fact that my Core2 blows me away, especially when chewing on audio work, or other multimedia intensive work.

Opinions are going to vary. I, for one think running a 64 bit system rocks. Other than the one 32 bit library blowing up, the system has been every bit as stable and usable as my two 32 bit systems...and then some.

Blessed be!

Pappy

----------

## c707176

Guys, 

thanks for sharing your experience.

zyko, in fact I am heavily involved with numerical simulations. However, most of these simulations are carried out on high performance computing centers anyway and not on my on pc. On the other hand it seems to be attractive to have a 64bit system dual core for testing and debugging purposes before going to the hpc which is somehow also the background for my question but first of all I need a stably running system for my daily work. And, yes I want to use 4GB of RAM (currently in my box) but probably not more.

Is there a safe way to upgrade from 32 bit to 64 bit Gentoo or could the 64 bit version be used on a separate partition?

Would standard applications such as firefox or acroread be supported in 64bit mode?Last edited by c707176 on Fri Nov 07, 2008 9:46 am; edited 1 time in total

----------

## energyman76b

 *zyko wrote:*   

>  *Quote:*   Is there any real advantage of using 64-bit gentoo? 
> 
> Only if:
> 
> 1. you run some very specific software that uses 64bit technology (like e.g. numerical simulation for your engineering PhD studies).
> ...

 

and that is wrong.

64bit does give you some speed advantages compiling, compressing and decompressing stuff. In fact, there is no reason at all not to go 64bit multilib.

----------

## zyko

 *Quote:*   

> Is there a safe way to upgrade from 32 bit to 64 bit Gentoo or could the 64 bit version be used on a separate partition?
> 
> Would standard applications such as firefox or acroread be supported in 64bit mode?

 

There's no (sane) way to upgrade from x86 to amd64. But amd64 can emulate x86 without a real performance penalty. Gentoo's amd64 stage3 tarball already comes with x86 emulation support enabled (called multilib). There used to be software that was considered problematic on amd64, but I believe those days are pretty much over by now.

 *Quote:*   

> 64bit does give you some speed advantages compiling, compressing and decompressing stuff. In fact, there is no reason at all not to go 64bit multilib.

 

There are some good reasons against amd64 (for users who actually don't need 64bit): Amd64 implies larger memory and hard drive space consumption and thus runs significantly slower on older hardware.

----------

