I'm trying to find benchmarks comparing the two solutions, but not having much luck. Anybody have any experience or opinions on the matter?

I have a Pentium d 820 2.8ghz in my rig and i have been pretty disappointed with the performance. JMO

ive seen tomshardware benchmarks put the a64's consistantly on-par or above the dualcore p4's

ymmv

hardocp.com has some really good write ups..

Do a little reseach and you'll see that a single threaded app running on a 2.8 gig cpu or a 2.8 gig dual core cpu will.. function the same. Even more so with Intel.. Intel took the route of taking 2 cpus and shrinking them down to fit in a single package. Peal back the heat spreader and you can see the 2 chips/cores. AMD has 2 cores on a single chip. Runs much faster and a much cooler.

I personally would go with a dual core over a 2 single cores because they put out less heat.

What do you plan on using them for?

I'm currently running 4 dual core cpus in my ibm p550 running informix and it seriously stomps the shit out of my 4 single core cpus running on my ibm p650.

I'm also talking money here. Obviously you can spend $1K on a nice dual core and it will outperform things.

Mostly though, I wasn't talking about single-core vs. dual core. Obviously a quad system running all dual cores is going to run faster than a quad system with single cores.


Let's say... a dual P4 3.2 ghtz vs. a SINGLE X2 4800. The dual Pentium system would cost slightly less. For the sake of argument, we are running in a multi-threaded invironment.

I don't know a whole lot about this, but it seems to make sense that a dual core should do at least as good as a dual processor if not better since the two processors have a more direct line of "communication" to each other and don't have to deal with the motherboards systems exept for direct input or output. On the other hand, that would only be the case for single task processes. Multitasking may be better suited for a dual processor system.
I am no expert in the field of computers and I may be completely wrong, but that's how I see it.

In the long run the 3.2 might cost "less" but due to power requirements it'll cost more in the future. It depends if you could care less about power. Its a silly arguement but in the long run it makes sense. The X2 should perform better, but depending on what kind of multi-threaded environment you plan on using it in. I've seen the X2s run Solaris and just *crush* at being a bad ass web server. With the 4800 being the flagship X2 chip right now, you could get the 4400 most likely for the same price as the dual 3.2s and still get better performance. If youre doing something thats highly memory intensive then you might want to go with the dual p3.2s because they run with the DDR2 ram modules. If you could wait a little while, AMD is phasing out the 939 pin out and moving to a 940 that will utilize DDR2-667mhz memory. Take into account the disk subsystem and how its laid out. That could effect your over all performance regardless of your cpu. I've seen wack ass raid cards be the complete bottle neck.

Is this just for arguement sake or something you are really trying to achive?

No, No.. youre pretty close. A lot of it really does come down come down to the application itself.

A friend of mine is building a computer. Personally, I'm not one to buy state-of-the-art hardware (it just doesn't make much financial sense to me). I thought somebody here might have had personal experience.

personally i got with a dual code x2 in a 939 pin out.. something like a 3800+ cause they really are at a great rate. Once the 940s hit the 4800+ will drop in some serious price in about 6 months.

http://www.digitimes.com/mobos/a20060213PR218.html

price cuts on intel chips in april.. just an fyi.