I have Win7 Ultimate 32bit installed on my PC now. I got a new HDD today and was gonna install my OS when I was thinking about something, Will a 64bit OS make a difference over a 32bit OS. There both Win7 Ultimate. This is my setup.

Case: Antec 902 v3
PSU: Thermaltake TR2 RX 750W
HDD: Seagate Barracuda 250gb
MB: GIGABYTE GA-MA78LMT-S2 AM3
CPU: AMD Phenom II X4 955 Black Edition 3.8ghz
RAM: 4gb 1333
GPU: GIGABYTE Radeon HD 5770 1GB

now in 32 you can only use like 3/4gbs of the ram but I have 4 so will it even make a difference?

There's no reason not too, really. You will get to use all of your RAM, and 64 bit is now fully supported by virtually everything.

think of 64bit as a small upgrade that will help optimize your pc a bit more.

You have 4GB of actual RAM and a further 1GB on your graphics card.

5GB in total would require a 64bit OS to address it all I think.

Bean0, you can have up to 4GB of RAM on a 32 bit operating system. Graphics card memory size is, AFAIK, unlimited and shouldn't stack with RAM (but the Graphics Card may still be limited to 4GB maximum size, however I don't think there's a graphics card out yet powerful enough to test that theory. lol)

Of course under XP, if you still prefer to run it (like me) then you will only get 3.5GB RAM due to the unique way in which Microsoft works. Good times.

Anyway, 64 bit is almost universally supported now so there's no reason to not get 64 bit.

Quote :

How graphics cards and other devices affect memory limits

Devices have to map their memory below 4 GB for compatibility with non-PAE-aware Windows releases. Therefore, if the system has 4GB of RAM, some of it is either disabled or is remapped above 4GB by the BIOS. If the memory is remapped, X64 Windows can use this memory. X86 client versions of Windows don’t support physical memory above the 4GB mark, so they can’t access these remapped regions. Any X64 Windows or X86 Server release can.

X86 client versions with PAE enabled do have a usable 37-bit (128 GB) physical address space. The limit that these versions impose is the highest permitted physical RAM address, not the size of the IO space. That means PAE-aware drivers can actually use physical space above 4 GB if they want. For example, drivers could map the “lost” memory regions located above 4 GB and expose this memory as a RAM disk.

http://msdn.microsoft.com/en-u ... a366778%28v=vs.85%29.aspx

Jamie. You don't know what you're talking about.

32 Bit can address 4 GB of memory. This does include GPU memory (as the GPU needs to be addressed by the CPU somehow to load textures somehow).

OSX can actually address infinite memory in 32 bit (using special tricks), but each process is limited to a 4 GB memory maximum. Although on all but the 32 bit Core Duo Macs.. Lion will basically run in a 64 bit kernel (Full 64 bit.. not just 64 bit processes on a 32 bit kernel) by next month.

Windows theoretically could do what OSX and Linux could do (PAE as Bean0 has explained).. but Microsoft seems to run into instability with PAE (while Linux and Apple devs can make it work just fine!)

Quote from Bean0 :

http://msdn.microsoft.com/en-u ... a366778%28v=vs.85%29.aspx

Wow I genuinly did not know that xD

Well, you learn something every day. I'm gonna go test that now.

If you read.. Windows enforces a 4 GB cap on 32 bit windows' even if it's running in PAE mode (for NX bit at bit 63).

The real benefit of a 64bit OS is that it allows you to run 64bit applications. These are for various reasons faster (sometimes lot faster), so if you do 3D modelling, video editing or some extensive photoshopping, you might want to move to 64bit. Game devs usually don't bother creating 64bit binaries for games, so you won't spot any difference there. 32bit apps on a 64bit OS can use all 4 GB of RAM they can address, but that's about it.
These were the pros, as for the cons, you might run into some drivers issues. Especially if you have some old piece of HW you might have a hard time finding the drivers for a 64 bit OS, sometimes they just don't exist. 64bit apps also use a bit more RAM.

Quote from dawesdust_12 :

32 Bit can address 4 GB of memory. This does include GPU memory (as the GPU needs to be addressed by the CPU somehow to load textures somehow).

It does not. CPU has no access to the graphics memory, it's the GPU that loads the textures from RAM. You're probably confusing this with AGP texturing.
(EDIT: CPU can get direct access to the framebuffer, IIRC SoftTH uses that. But the total video RAM is not just the framebuffer)

Quote from dawesdust_12 :

Lion will basically run in a 64 bit kernel (Full 64 bit.. not just 64 bit processes on a 32 bit kernel) by next month.

This is actually the other way around, ain't it? The whole shell of MacOS X is now 32bit running on top of a 64bit kernel.

Quote from dawesdust_12 :

Windows theoretically could do what OSX and Linux could do (PAE as Bean0 has explained).. but Microsoft seems to run into instability with PAE (while Linux and Apple devs can make it work just fine!)

AFAIK PAE works fine in Windows, you can enable it in boot.ini and try it for yourself. MS uses it in their server OSes. However, it doesn't come with any performance speedup (it actually slows things down a little) and doesn't solve the problem of a single 32bit app not being able to address more that 4 GB of RAM. Phoronix posted a nice "32bit vs 32bit PAE vs 64bit" bechmark of Linux and the results were pretty convincing. On the other hand it was mostly the 64bit apps that helped the 64bit to the shattering win, not just the 64bit kernel.

No. OSX in its current state on most modern OSX machines runs a 64 bit kernel with 64 bit applications. Older Mac's running SL will run 64 bit apps on a 32 bit kernel.

Lion will be the second Mac OS with a wide sweeping support of 64 bit kernel and 64 bit applications. SL had 64 bit kernel support as well, but only for certain Macs. Lion seems to jack that up quite a bit.

Quote from dawesdust_12 :

No. OSX in its current state on most modern OSX machines runs a 64 bit kernel with 64 bit applications. Older Mac's running SL will run 64 bit apps on a 32 bit kernel.

I wonder how is that accomplished. At least the memory management part of the kernel has to be 64bit, right? It's also interesting that 64bit kernel with 64bit apps seems to perform a bit better... It's a sham that google didn't point me to any technical explanation.

I do alot of video editing with Sony Vegas and AAE so I guess I'll upgrade to 64bit Will be done later.

Thanks guys

Quote from MadCatX :

I wonder how is that accomplished. At least the memory management part of the kernel has to be 64bit, right? It's also interesting that 64bit kernel with 64bit apps seems to perform a bit better... It's a sham that google didn't point me to any technical explanation.

Well, 64 bit apps on the 32 bit kernel use PAE as earlier explained.. so they are still restricted to 4 GB of RAM, but that's per application, not system-wide... a "middle-ground" between 32 on 32 and 64 on 64.

Quote from S14 DRIFT :

Of course under XP, if you still prefer to run it (like me) then you will only get 3.5GB RAM due to the unique way in which Microsoft works. Good times.

It's nothing to do with Microsoft, it's memory reserved for IRQ space iirc.

Quote from dawesdust_12 :

Windows theoretically could do what OSX and Linux could do (PAE as Bean0 has explained).. but Microsoft seems to run into instability with PAE (while Linux and Apple devs can make it work just fine!)

who cares? windows has been available as a fully functional 64 bit version since 2005 (ie about 2 years after the first 64 bit x86 processors came out to make such a thing at all necessary) and has been compatible with pretty much anything but the most obscure of hardware since at least 2007

pae is a stopgap solution that has (had) very little (if any) relevance outside the server market

To the op: Honestly, 64-bit is better than 32-bit. Not only will you be able to use 4+ GB of ram but you'll also be using the computer to its full potential because a 64-bit OS uses 64-bit instructions (obviously), and your CPU, motherboard, and RAM were designed to handle 64-bit instructions. So at the very least you'll be able to send more data per instruction, and as a result you might notice a slight speed boost.

Quote from MadCatX :

AFAIK PAE works fine in Windows, you can enable it in boot.ini and try it for yourself.

It works. But not as it should. Only advantage in a non-server windoze OS with PAE you get is the NX-bit. It's still limited to 4GB of RAM. Something about a driver compatibility/stability issue and a whole more yadda yadda(licensing) from M$.

So anyway, if you already have 4GB of RAM, I would go with 64-bit version of windoze. You never know when you're going to upgrade your RAM. And are you going to re-install it again just because of that?