Programming on an AMD Athlon 64 X2

[yasunobu13]

Anyone have any experience programming with an AMD Athlon 64 X2? It's got that fancy shmancy dual core, does that kick into gear with any multithreaded program? Also, is there any way to use 64 bit types if it's running on a 32 bit version of windows? Is there any way to take advantage of it's 64 bit properties on a 32 bit operating system?

I can't really find much information on the AMD site.

[Asclepeos]

Are you a programmer or a high-end game player?

[Jeff2A]

Anyone have any experience programming with an AMD Athlon 64 X2? It's got that fancy shmancy dual core, does that kick into gear with any multithreaded program? Also, is there any way to use 64 bit types if it's running on a 32 bit version of windows? .

u_int_64 and fork(), but you'll need the 64 bit version of windows to get the high memory. Using 64 bit data types on 32bit os = slower than 32 on 32.

[yasunobu13]

Are you a programmer or a high-end game player?

I am a programmer working in a 3d lab at the university who just got 3 brand spanking new computers to run our NVidia Quadro 4500s that NVidia was generous enough to donate to run our wall size immersive display. *gloat*


@Jeff2A
So I am right in thinking that 64 bit datatypes are pointless without a 64 bit operating system. Not that important.

[Jeff2A]

@Jeff2A
So I am right in thinking that 64 bit datatypes are pointless without a 64 bit operating system. Not that important.

No, that's not true at all ...

You'll use 64 bit types when you need numbers larger than 2^32-1, or signed integers larger (or smaller) than 2^16-1.

The point is - you could use those 64 bit types on 32bit operating systems and 32bit chips, it was just slower. Moreover, the extra features in x86-64 are really operating-system level (using 64 bit types for memory addresses, for example), nothing you'll likely see doing userland programming (UNLESS you're doing some pretty hard core graphics, but ... if you were ... you'd probably already know this).

I guess my point is the same thing I always say when people ask me if they should buy a 64bit processor: if you needed it, you'd already know the answer. If you don't know WHAT you're going to do with twice as many bits, you're probably fine using standard 32bit anyway.

[yasunobu13]

Oh, I could think of plenty of things to do with those extra bits. I'll just have to fiddle to see if it's worth it.

[krona]

One thing that wasn't mentioned was the 8 additional registers AMD64 offers in pure 64-bit mode, which gives a large perf boost in execution speed. You don't have access to these when the processor is running in 32bit mode. Thing is, unless you're writing in assembly or something close to it, the compiler should take care of using those registers effectively, so you don't have to bother with them.

As regards to the chip being dual core, yes, individual applications can take advantage of the extra core if they are 1) multi-threaded and 2) written well enough (ie. not putting thread blocking statements all over your code because you can't figure out how to make your code thread safe and synchronized). The OS can also take advantage of the 2 cores, by executing two single-threaded apps at the same time.

[yasunobu13]

One thing that wasn't mentioned was the 8 additional registers AMD64 offers in pure 64-bit mode, which gives a large perf boost in execution speed. You don't have access to these when the processor is running in 32bit mode. Thing is, unless you're writing in assembly or something close to it, the compiler should take care of using those registers effectively, so you don't have to bother with them.

As regards to the chip being dual core, yes, individual applications can take advantage of the extra core if they are 1) multi-threaded and 2) written well enough (ie. not putting thread blocking statements all over your code because you can't figure out how to make your code thread safe and synchronized). The OS can also take advantage of the 2 cores, by executing two single-threaded apps at the same time.

That's just what I wanted to know. Thanks everyone!

[Jeff2A]

Thing is, unless you're writing in assembly or something close to it, the compiler should take care of using those registers effectively, so you don't have to bother with them.

To be completely honest, I haven't looked at MS VS 2005, but I the last time I looked at gcc/g++, the latest versions of gcc made very poor use of those extra registers.

[ViRGo_RK]

I am a programmer working in a 3d lab at the university who just got 3 brand spanking new computers to run our NVidia Quadro 4500s that NVidia was generous enough to donate to run our wall size immersive display. *gloat*

Lucky.