According to Toms Hardware, there isn't a lot in the performance difference between the two - though the "multimedia" floating point (important for audio processing) is better on P4's. AMD's benefit from the onboard memory controller, Intel's from the enormous L2 cache (2 x 2meg!). The Intel can also take faster memory. There's a chance AMD's will be "quieter", as they draw less power, create less heat and thus require less cooling, but the difference is probably negligable (and heavily dependent on the range of coolers for each socket).

For me, I will always go the Intel route as I have found Intel systems to be much more stable. AMD don't make chipset's, so you have a different manufacturer for CPU, chipset and potentially motherboard. Too many cooks, and some of them only know how to use a microwave (e.g. VIA).

The big difference is the price, and traditionally Intel are much more expensive. Since the case is reversed here for you, I'd seize the offer and go for the Intel. Though it's difficult to say what's causing the higher price in the AMD without knowing the other system components - if it's Intel CPU on a non-Intel chipset, avoid it and ask for a quote for an Intel chipset. I'd be surprised if you couldn't drive the prices down, and even fit better components, if you assembled the system yourself - it's not hard, a bit like IKEA furniture.

Hope this helps,
Chris

PS: If you can get a more detailed description of each system, post it here and I'll take a quick recky.

Definitely Intel, then - Asus are an excellent manufacturer. It sounds like you local shop isn't trying to cut costs or push up profit margins, but instead picking quality components, and that sells them for me. Note: if you want a silent performance graphics card with dual DVI, I can recommend the Club3D X1300PRO (CGAX-HP136). Not easy to get hold of though.

Chris

Do plugins and hosts use dual cores in an intelligent way, or just 100% on cpu 1 and nothing on cpu 2?

Some, but not all. Cubase does, as should the other major products. Logic 5, obviously, won't. Over time, this will change. Not only will more programmers support dual cores, but compilers and kernels will probably start taking advantage of them without the lay programmer knowing! Dual cores, from the programmers perspective, are more-or-less the same as dual cpu's, so it's not as though the tools aren't already available to write dual-cpu programs. It can be tricky, though, and it is possible that until dual-core coding becomes commonplace there are going to be a few more bugs than normal. Succinctly put: if you have two CPU's working with the same memory and same HDD, they're going to get in each other's way every now and then!

Is the audio-market 64bit-ready actually?

Much the same case, but slightly further along. Also - although I haven't tested this - my experience is that a lot of modern (though pre-64bit) audio programs use 64-bit variables (double's) even in 32-bit environments - so it's possible these programs will see a boost from 64-bit processors anyway. The compatibility, however, is usually not the onus of the CPU, but the operating system. If the OS is 64-bit, you need a 64-bit ready application, but if the OS is 32-bit, you won't have any problems. Bottomline: install 64-bit and 32-bit Windows on the same 64-bit system. The performance doesn't appear to suffer with a 32-bit OS running on a 64-bit CPU (compared to a 32-bit CPU), and it seams to be just as compatible with older applications as a 32-bit OS on 32-bit CPU - but you probably won't get any performance boost - not even if the program tries to use the 64-bit advantage (the 32-bit OS effectively prevents that).

Do important soundcards have 64bit drivers? (no betas or otherwise unofficial stuff like my "terratec 7.1 space")

Most soundcards will, but it depend more heavily upon their age. Still, many drivers are still going through beta stage, even now. The Terratec Aureon 7.1 Space's beta is at http://supporten.terratec.net/modules.php?op=modload&name=Downloads&file=index&req=getit&lid=1260. It's not that difficult to produce a 32-bit to 64-bit conversion that will work, but it is more complicated to boost (or even sometimes retain) the performance of 32-bit drivers on 32-bit systems.

* * *

Today, I strongly recommend jumping on the 64-bit and dual-core bandwagons. The performance boost will come (for some it will already have), but until then performance in 32-bit "mode" will still compare with 32-bit CPU's. It's a similar story for dual-cores.

Hope this helps,

Happy purchasing,
Chris

PS: It's a bit of moot issue really. "Going the 64-bit / dual-core route" is more or less obligatory these days - most new performance processors will have these features.