I have been looking in many posts trying to find an answer but I couldn't so I am opening a new thread.

I would like someone to tell me exactly what are the advantages of a
64 bits versus a 32 bits system

Thanks for your help.

jack

A single process can access more memory than 32 bit, however the downside is that 64 bit by it's nature actually tends to chew up more memory. There's a negligible speed advantage(memory access issues aside).

In the end, everything is going 64 bits, I don't even think you can buy new 32 bit computers anymore can you? Apart from old stock, that is. You shouldn't feel like you're living in a bad place because you're 32 bit, however. My attitude is to let 64 take over gradually as you upgrade your computers, but don't have 64 bit envy.

Cheers,

J.C.

First off, thanks for your answer.

So, If I understand well it really depends on the software, right?
If you have a 64 bits system, but your apps do not take advantage of
it then it is worthless. Windows XP impose restrictions on the max memory
available to applications, but what about linux and XP or Vista 64?

Oh, I forgot one rather important thing - maximum amount of system memory. 64 bit will get you more(but will gobble it up slightly more!). If you're regularly running out of memory in 4G and feel you need more, then 64 bit is worth it.

The memory restrictions are literally tied to the hardware, it's not OS-related(although yup - a 32 bit program can't exceed the maximum). I would take your initial statement one step further and say there is no point in going out of your way in getting 64 bit unless you're upgrading(in which case you can't avoid it), or you regularly find you actually *need* large datasets in memory in single instances.

Cheers,

J.C.

Hi

I recently got a new 8 core machine for work and 8 GB of ram, and I finally installed ubuntu linux 64 bit, to take advantage of all the system.

I had before a 4 cores machine with 4 gb or ram and always worked with 32 bit, cause, yes, 64 bit requires more memory per task, some say is double the ram, so now that I have enough I went 64 and yes I'm having a nice time

A couple of things I should mention, 64 bit windows is not that good, seems like they just made the system 64 and NOT optimized it to really work like that, for this kinds of really hard stuff I will always choose to do them in linux, like rendering simulation, compositing, cloth, etc, linux is much more stable, crash less and once you get windows out of your system, actually friendlier that windows, and now with the latest WINE you can run almost anything inside linux even ZBrush.

One other thing, linux has PAE kernels, this is simply put, a 32 bit kernel that supports more ram that the regular 32 bit, I think it goes up to 64gb of ram, so if you only need to use more ram, you can use that, centOS linux installs that automatically if you have 4 or more gb or ram.

To finish I will say, go 64 if you have enough ram and more importantly if you are gonna make your machine really really work hard, if not you might not see almost any difference.

Hope this helps you and if you haven't, try linux, make your computer work like it supposed to
www.ubuntu.com [ubuntu.com]

Just a quick note on PAE (on 32-bit machines)…

Yes, you can get more than 4 GB in your machine, and the kernel can make use of it for all sorts of things like caches and buffers.

But no single process can use more than 4 GB of memory.

So you can run more processes without swapping, but if your data set for one process is more than 4 GB you're going to be out of luck on a 32-bit system.

varomix
One other thing, linux has PAE kernels, this is simply put, a 32 bit kernel that supports more ram that the regular 32 bit, I think it goes up to 64gb of ram, so if you only need to use more ram, you can use that, centOS linux installs that automatically if you have 4 or more gb or ram.

Note that the 64GB limit is only for all total processes combined. Under 32-bit with PAE, a single process can still only address up to 3 GB by default. Apparently, there are experimental 32-bit linux kernel patches that let you go up to 4 GB per process, but then it incurs a 10-20% speed penalty. IMHO, if you have that much ram, you really shouldn't be running a 32-bit OS anyhow.

One important note about the maximum supported memory of a motherboard… A motherboard will often advertise a maximum supported amount of memory, like 8GB or 16GB. This is the amount of memory that a motherboard can address, and this includes the memory mapped devices on the motherboard itself, like the PCE-Express slots, USB ports, ethernet interface, etc.

If you install 8GB of RAM on a motherboard that supports 8GB of memory, you'll actually get slightly less available RAM than the advertised maximum (say, 7.2-7.6GB). The exact amount taken by memory mapped device IO depends on the number of devices and what they are. If you install less than the maximum (say 6GB) you'll have full access to the RAM.