64 vs 32

[SoftwareHouse]

This question has probably already been asked but will a 64 bit processor run a 32 bit application better then a 32 bit processor? Or would it be better to use a 32 bit until the applications are 64??

[Un4given]

The 64-bit processors are actually 32-bit processors with additional x86 extensions that add 64-bit functionality. There is no loss of performance running a 32-bit application under the AMD or Intel x86 based 64-bit chips.

[r'aggro]

In fact, a64 runs 32 bit apps at least as well as any 32 bit processor.

[bisonator]

does he mean running 32bit apps on a 64bit OS ?

to which I beleive there is a small performance overhead because of 32bit emulation.

[ewitte]

I don't thing A64 has to emulate anything 32-bit even with x64. Its just ran without the 64 bit extensions. If you want to see emulation losses look at Itanium. Great processor if you support it. With emulation the speeds like 25%.

[ua549]

There is no performance hit. If anything there is a boost due to the efficiency improvements of the 64 bit operating system.

Here is an excerpt of a chat with Microsoft on the subject.

[ewitte]

I've ran a few of the X64 betas. What wasn't buggy or optimized for 64bit was pretty much the same speed. There is mainly a difference of +5% or -5% depending on the application.

[kent1146]

I think that the general state of 64-bit computing is that the hardware itself makes no difference. There is no performance hit when you use a 64-bit capable processor (like an Athlon64) to run a 32-bit OS. So go ahead and buy a 64-bit capable processor, if that is what you want.

The only question is whether you run a 64-bit OS. Right now, it isn't worth tinkering with Windows XP 64-bit at the moment, unless you have specific applications that are 64-bit and want to run those optimized applications. There are some issues like driver support and application incompatability that make it not worth using Windows XP 64-bit. For everyday use running 32-bit applications, stick with a 32-bit OS.

[SoftwareHouse]

I meant running on a 32 bit OS. My asumption would be to buy a 64 bit processor so that when application are using 64 i can upgrade my OS.

[kent1146]

Yes, that would be fine. Almost everybody with an Athlon64 (and there are quite a few of us) are thinking exactly the same thing you are.

[ImaNihilist]

Yes, that would be fine. Almost everybody with an Athlon64 (and there are quite a few of us) are thinking exactly the same thing you are.

Unfortunately, everyone with an Athlon 64 won't be able to use one of the major benefits of 64-bit computing, which is addressable memory beyond 4GB. Most Athlon 64 setups can't run 4 DIMMs, 4GB, or 1T with more than two DIMMs. So much for the great integrated memory controller.

Opteron and nForce 4 Proffessional though...that's another story.