Win 7, 64 vs 32, Help please :)

[MagicalTrevor]

People really need to stop asking this question.

 

[Tonester007]

OP: Unless PAE is switched on then 32 bit Windows can only address a total of 2^32 bytes which works out at 4 Gb. This limit also includes the memory on your graphics card, so if you also have a 1Gb graphics card then you would only be able to use 3Gb of system memory.

64 bit can address 2^64 bytes or 17,592,186,044,416 Gb. However Microsoft have imposed a limit of 192 Gb for Win7 Ultimate & Pro and 16Gb for Win7 Home Premium.

I'm using 64 bit Ultimate on my desktop and it is running fine - no problems with drivers. Win7 is also a lot more stable than XP. Go for 64 bit

 

[Fire Wizard]

If not, settle for 32-bit, there's very little in it performance wise as most applications are still built for 32-bit. And with Windows 7 32-bit supporting PAE, there's no more 4GiB limit for your memory, only for a single process.

Even though client versions of Windows can theoretically address more than 4GB, the reason why they don't is merely due to a licensing limitation. Windows 32-but client SKUs are only licensed for up to 4GB of physical memory.

Windows Client Memory Limits:

64-bit Windows client SKUs support different amounts of memory as a SKU-differentiating feature, with the low end being 512MB for Windows XP Starter to 128GB for Vista Ultimate and 192GB for Windows 7 Ultimate. All 32-bit Windows client SKUs, however, including Windows Vista, Windows XP and Windows 2000 Professional, support a maximum of 4GB of physical memory. 4GB is the highest physical address accessible with the standard x86 memory management mode. Originally, there was no need to even consider support for more than 4GB on clients because that amount of memory was rare, even on servers.

However, by the time Windows XP SP2 was under development, client systems with more than 4GB were foreseeable, so the Windows team started broadly testing Windows XP on systems with more than 4GB of memory. Windows XP SP2 also enabled Physical Address Extensions (PAE) support by default on hardware that implements no-execute memory because its required for Data Execution Prevention (DEP), but that also enables support for more than 4GB of memory.

What they found was that many of the systems would crash, hang, or become unbootable because some device drivers, commonly those for video and audio devices that are found typically on clients but not servers, were not programmed to expect physical addresses larger than 4GB. As a result, the drivers truncated such addresses, resulting in memory corruptions and corruption side effects. Server systems commonly have more generic devices and with simpler and more stable drivers, and therefore hadn't generally surfaced these problems. The problematic client driver ecosystem led to the decision for client SKUs to ignore physical memory that resides above 4GB, even though they can theoretically address it.

Pushing the Limits of Windows: Physical Memory

As far as 32-bit processes go, they're still limited to 2GB, unless the user address space has been increased to 3GB and the process is large_address_space aware.