32-bit vs 64-bit

[Worr]

Heya, I have this new machine:

eVGA 680i mobo
Intel Q6600
GeForce 8800GTX
4gb Patriot DDR2 800
2x74gb 10k rpm hdd

I'm currently running Vista Business 32-bit. 32-bit processors only support a maximum of 4gb of ram, including the pagefile. This is where I'm having the issue. I've got a gig of virtual memory and 4gb of physical memory, which means this 32-bit processor is only utilizing 3gb of my physical memory.

I can grab a copy of Vista 64-bit, but I was just wondering what else I'd need to do. I hear 64-bit drivers are very hard to find, and I hear that there are a lot of programs that won't even work with 64-bit. Does anyone here have a 64-bit OS, and are you experiencing any notable problems with it?

[Ewan]

I've been running Vista Home Premium x64 since April.

I've had no problems finding drivers for anything.

The only program I've had problem running was 3Dmark06 where I had to download an extra file.


Seeing as your computer is new, all your hardware will be supported by Vista x64. The only things that really seem to have problems are old (no longer supported hardware) and I think some of the Creative sound cards.


Definitely get the 64-bit version or you will be simply wasting that 4gb of RAM.

[Ephemeral]

He's only wasting disk space, not RAM. If this is the only reason he has for moving to 64-bit, why do it? Swapping out to the hard drive is slowwww anyway. Simply reduce the swap file.

[Ewan]

What are you talking about Ephemeral? This has nothing to do with hard disk space.

A 32-bit OS can only address 4gb TOTAL physical memory. I don't think this applies to virtual memory (in fact reading through his post, I am pretty sure he's misunderstood the cause of the problem), but any physical memory in the computer including the graphics card uses up this 4GB. In his case, his graphics card has 768mb of RAM. This 768mb is taken out of the 4gb total so it can be addressed by the OS. This means that 4gb-768mb of actual RAM is available to use, wasting nearly a GB.

[Ephemeral]

Perhaps I am mis-understanding his nomenclature, but when someone says 'virtual memory' the assumption is usually that it means the HD swap file.

[a21ozcoldcup]

What are you talking about Ephemeral? This has nothing to do with hard disk space.

A 32-bit OS can only address 4gb TOTAL physical memory. I don't think this applies to virtual memory (in fact reading through his post, I am pretty sure he's misunderstood the cause of the problem), but any physical memory in the computer including the graphics card uses up this 4GB. In his case, his graphics card has 768mb of RAM. This 768mb is taken out of the 4gb total so it can be addressed by the OS. This means that 4gb-768mb of actual RAM is available to use, wasting nearly a GB.

This I did not know. So you're saying if I have a 32bit OS, even if I have a dedicated video card that isn't mooching off my RAM, it will count towards my 4GB limit for physical memory? Why not just buy a 64bit OS now, as it's inevitable that within a few years the 32bit ones will be obsolete...?

[Ephemeral]

What are you talking about Ephemeral? This has nothing to do with hard disk space.

A 32-bit OS can only address 4gb TOTAL physical memory. I don't think this applies to virtual memory (in fact reading through his post, I am pretty sure he's misunderstood the cause of the problem), but any physical memory in the computer including the graphics card uses up this 4GB. In his case, his graphics card has 768mb of RAM. This 768mb is taken out of the 4gb total so it can be addressed by the OS. This means that 4gb-768mb of actual RAM is available to use, wasting nearly a GB.

My opinion that this is not the case, the video (or I/O address space) is independent of the system memory address space. But perhaps I am not up on the most cutting edge stuff.

[Displaced]

im inclined to agree with eph on this matter...

[Ewan]

From http://support.microsoft.com/kb/929605

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

[Worr]

It was my understanding that the virtual memory was included in the maximum system memory. Therefore even if I had 100mb of virtual memory, i still wouldn't be utilizing my 4gb of ram. I wasn't under the impression that GDDR was considered system memory, but I can see where that would be a factor.

I have yet to find a reason not to go to 64-bit. Especially with Vista, you're going to want more memory, and it seems for some games coming soon, you might even want to exceed the 4gb of physical memory.

Either way, I grabbed a copy of Vista 64-bit, and now it recognizes my 4GB of ram with the addition of a 1GB of virtual memory. So far, so good. I can't complain.

Thanks for your help, Ewan. Glad someone had experience with it!

[Blocks]

I had a few driver issues with 64-bit Vista on my laptop -- ended up never getting my modem working.

There's a few things that plain don't work on 64-bit, and there's no 64-bit version for. One of them is the Cisco VPN Client, which was enough for me switch back to 32-bit this summer.