I've been searching around for a while and couldn't find any tests that really pit a dual core CPU vs. a single core, where the single core has a (much) higher clock rate.

Recently I've been putting time and effort into researching available computer hardware available, both pre-built desktops and laptops and individual components (for a DIY approach) for both. This is conducted with the view to buying/building a new system in the not-too-distant-future, and really, I want to future-proof it to a fairly good degree. So I've been weighing up the merits of the new 64-bit architecture vs. 32-bit, various expansion slot types, and different individual components (motherboards, processors, RAM etc). I've now hit a bit of a stumbling block over single core or dual core (or dual single core) of varying clock speeds.

The example I'm puzzling over really is this:

One dual core AMD (64 bit), each core clocked at 2.2 GHz (Most expensive option)
One single core Intel (64 bit) clocked at 3.0 GHz (considerably cheaper)

Or maybe even two single core at about 2.0-2.2 GHz? However as far as I've seen, the motherboards intended for this tend to be much more expensive "server" motherboards, so I think that might work out more expensive in any case.

On the whole, the second option seems a more attractive proposition, especially as it is much cheaper. However, I would at least consider the dual core if I knew it would give a marked performance increase/would be more "future proof" than the single core option.

Not to mention, they also tend to require ECC memory.

Ultimately, it depends on what you're doing with it. If you're a one-app-at-a-time person, a fast single core might be better. But a Linux/unix system is a multitasking system. If you're editing, compiling, listening to mp3s, watching mplayer, playing games, etc etc and doing two or more of those simultaneously, then a dual-core will probably be more beneficial.

Personally, I'd go for a dual-core Athlon 64. (Well, if I had the money, I'd get a dual-cpu dual-core Opteron... aaaaaah... just dreaming ).

If you're not desperate, you might want to wait a few months for the new Intel processor to come out (the name has temporarily escaped me, damn brain). Hopefully, that will nudge AMD to cut the price of the Athlon.

What's that!

I do tend to run a lot of software at once. On the other hand, I'm currently running Windows XP on a single core system (AMD Athlon XP, 1.4 GHz I think) and I'm able to have several instances of Firefox open, Winamp, the GIMP, and other programs... So I'm not convinced that single cores are exactly bad at multitasking. However as you say, dual core would be better at it.



What indeed? OK, I meant that it wouldn't suddenly be overtaken by the demands of software I guess that's less likely to happen on the OSS scene than the proprietary (and especially high end games... especially from persistantly "next gen" people like ID ) so I probably shouldn't worry so much about "future proof". On the other hand, I doubt that much software is actually likely to exceed the need for 3GHz (or thereabouts) in the near future. If I can find a fast dual core CPU at a reasonable price though I may well consider that. For now though, unless I find some compelling reason, I think I'll be sticking with single core.

Well, so would I... but I don't have the sort of money that I expect that setup would cost... (Plus money for other hardware too :S)

Thanks for that post though It's helped clarify a few things.

Indeed, there is definitely a point of diminishing returns with increasing clock speed.

Mmm, it's difficult to know what would be best, in which case the cheaper single-core option might be the way to go. Several times, I've spent $$$ upgrading only to find that the performance gain wasn't what I'd hoped for. I just checked the prices and a 2.2GHz dual-core Athlon 64 is considerably more expensive than a 3GHz P4. Damn, I thought the difference was less than that, I'd find that hard to justify too.