The maximum amount of DRAM that the 32-bit version of Windows 7 Home Basic OS can read is 4GB. The 64-bit version of Windows 7 can read up to 192GB DRAM. The maximum limit of DRAM on the 32-bit version of Windows 8 is also 4GB while the 64-bit version can handle up to 512GB of dynamic random-access memory. Here are the physical memory limits.
Similar to a Windows-based computer, Linux-based machines' maximum RAM is based on whether they have 32-bit or 64-bit architecture. Most 32-bit Linux systems only support 4 GB of RAM, unless the PAE kernel is enabled, which allows a 64 GB max. However, 64-bit variants support between 1 and 256 TB.
I downloaded Nightly, the beta 64-bit browser from Firefox, and also JAVA 7 64 bit version. I haven't yet found my new heap limit, but I just opened a JVM with a heap size of 5900m. No problem! I am running Win 7 64 bit Ultimate on a machine with 24gb RAM.
I have a choice of running 64 bit and 32 bit windows 7. I have the i5 intel duo core 2.27 processor and 4 GB memory laptop. I am not planning on sucking up lots a memory with a ton of applications running at once so the memory management with the 64 bit is not all that necessary. I am looking for performance so which would be better for me?
One of the major differences between a 32-bit and 64-bit Windows is the support for more than 4GB of RAM. Here is good news for Windows 8, 7 and Vista users because we have some patches here to make your 32-bit Windows support more than 4GB of memory.
From what I understand, running two machines with the same specifications (one 32-bit, one 64-bit) with a small amount of RAM (say 2GB), will have the 64-bit machine running slightly faster. Based on some test results, a 64-bit machine might run approximately 10% faster -- but it comes at a cost: RAM consumption is much higher with approximately 30% more overhead.
The Windows 32-bit protected-mode cache driver (Vcache) determines the maximum cache size based on the amount of RAM that is present when Windows starts. Vcache then reserves enough memory.
While the maximum RAM limit for 32-bit Windows 7 editions is 4GB, when it comes to the 64-bit editions, the amount of memory that the OS can address depends on which edition you are running.Here are the upper RAM limits for the different editions of Windows 7: Starter: 8GB.