32-bit

We have Core2 machines (Dell T5400) with XP64. We observe that when running 32-bit processes, the performance of memcpy is on the order of 1.2GByte/s; however memcpy in a 64-bit process achieves about 2.2GByte/s (or 2.4GByte/s with the Intel compiler CRT's memcpy). While the initial reaction might be to just explain this away as due to the wider registers available in 64-bit code, we observe that our own memcpy-like SSE assembly code (which should be using 128-bit wide load-stores regardless of 32/64-bitness of the process) demonstrates similar upper limits on the copy bandwidth it achieves.

I'm sure we've all heard the terms 64bit and 32bit thrown around, but what do they actually mean? I'm pretty sure they have to do with the size of a memory address. On a 64bit machine, a reference to an object is 64 bits. But I want to dig a little deeper.... One often hears the phrase "64bit machine." What part of the computer is actually geared toward the number of bits? Processor? Operating System? What is the advantage of having larger memory addresses? I could add more questions, but I think brief is better. Thanks guys :D b w 64 bit refers to the width of registers, memory addressing

I am using 32bit Intellij on my 32bit windows XP with 4 GB of RAM. I am attempting to increase intellij xmx to 1.5GB : -Xmx1500m So I know JVM support 1.5GB of RAM in 32bit systems. But this error throws from JVM : The JVM could not be started. The maximum heap size (-Xmx) might be too large ... I can't increase intellij Xmx more than 900MB Please help me! You can't do it as JVM needs to allocate all the heap in a single continuous chunk, which may not be possible because of the memory fragmentation. See my FAQ article for more details. See also this picture: As you can notice, total process

What is the best 32bit hash function for relatively short strings? Strings are tag names that consist of English letters, numbers, spaces and some additional characters ( # , $ , . , ...). For example: Unit testing , C# 2.0 . I am looking for 'best' as in 'minimal collisions', performance is not important for my goals. If performance isn't important, simply take a secure hash such as MD5 or SHA1, and truncate its output to 32 bits. This will give you a distribution of hash codes that's indistinguishable from random. I'm not sure if it's the best choice, but here is a hash function for strings:

According to this MSDN page : WOW64 enables 32-bit applications to take advantage of the 64-bit kernel. Therefore, 32-bit applications can use a larger number of kernel handles and window handles. However, 32-bit applications may not be able to create as many threads under WOW64 as they can when running natively on x86-based systems because WOW64 allocates an additional 64-bit stack (usually 512 KB) for each thread. In addition, some amount of address space is reserved for WOW64 itself and the data structures it uses. The amount reserved depends on the processor; more is reserved on the Intel

I am currently learning Assembly language on Linux. I have been using the book 'Programming From the Ground Up' and all the examples are 32-bit. My OS is 64-bit and I have been trying to do all the examples in 64-bit. I am having trouble however: .section .data .section .text .global _start _start: movq $60, %rax movq $2, %rbx int $0x80 This merely just calls the Linux exit System call or it should. Instead it causes a SEG FAULT and when I instead do this .section .data .section .text .global _start _start: movq $1, %rax movq $2, %rbx int $0x80 it works. Clearly the problem is the value I move

How do I force a 32-bit build of Boost with GCC? Currently attempting by putting this line in my user-config.jam , but it does not work: using gcc : 4.1.2 : g++ : compileflags="-m32" ; If you are using C++ Boost 1.40, use: bjam address-model=32 If you are using eariler version, consider upgrading. If you cannot, use bjam address-model=32 architecture=x86 I also recommend that you take a look at the fine manual Andrew Meadows This answer helped me toward a solution that worked for me. I was trying to compile a 32-bits version of boost_1_43_0 on 64-bits debian and eventually came up with this: .