Please help me understand dual core

[BriSleep]

Ok, my neighbor (Tim) used be a tech at a computer store. I'm looking to upgrade my current system because it's old (except the vid card) and I need better hardware to run Oblivion.
First of all I've been an AMD guy for quite a while now and have not studied much about intel processors. My friend in New Zeland switched to intel and he says that hyperthreading has made a major difference. Can someone tell me what hyperthreading does, how it works, in real world terms, please.
Next, Tim says that a dual core processor will work like 1 1/2 the rated speed so that if I got a 3.0Ghz dual core Pentium it will be like running an Althlon X64 at 4Ghz. Can someone explain this to me, is this assesment true? I want the most for my money and I don't want the reason to be something like "because intel kicks butt dude". So, if I'm running a low speed intel dual core, like a Conroe, will it really seem to be much faster than it's stated speed or is it just better for me to get the highest speed regular P4 that I can afford.

 

[GoldenTiger]

It's late and I'm tired, so forgive the brief and terse responses:

HyperThreading makes a "virtual" second core so that the operating system can juggle back and forth between multiple tasks more efficiently, in a nut-shell.

Dual-core means it is literally two CPU's on one CPU package/chip. It is like having an SMP system (Symmetric-Multi-Processing).

Efficiency/IPC (Instructions Per Clock) factor into the performance of a CPU, not just mhz rating. A normal P4 at 3.0ghz will get beaten by a 2.2ghz Athlon 64, for instance. This is due to the fact that they do more "work" per mhz that they operate at.

The P4 is a much lower IPC CPU than the Athlon 64. The Conroe is an even more efficient CPU than the Athlon 64 by about 20-25%. Therefore, an Athlon 64 at 2.5ghz would be about equal to a Conroe at 2.0-2.1ghz in the real world.

Dual-core CPU's are much faster overall, even in games due to driver optimizations and background tasks such as AV/antispyware/firewall/whatever you want (music or whatnot) while you game. In normal apps such as photo editting, rendering, encoding, etc. they are much much faster (nearly twice as fast) because those applications are specifically designed to split the work between the two cores and run it simultaneously.

Many games will be phasing to support Dual-core natively, (I'm harping on this because you mentioned Oblivion), some already do such as Call of Duty 2, Quake 4, Doom 3-engine, Unreal Engine 3, supposedly Oblivion, etc. Obviously MMORPG's dual-logging with 2 copies would run as two seperate games to the computer and would benefit immensely.

Basically, as you can see, there's no real reason to go for a single-core CPU if you're buying new and have a low "mid-end" or better budget. The single core may be clocked a little faster (though even that isn't the case now most of the time), but the second "CPU" is physical, whereas in HyperThreading it is virtual. In this case it actually is doing the work, not just helping efficiency. This goes for, of course, any Dual-core CPU.

Hope this helps...

 

[StealthyFish]

Conroe will produce more performance at a lower clock due to the length of the processor's pipelines (btw, i believe conroe has 3 while all other processors have 2 per core). I think the guy above explained it pretty well. Hyperthreading tricks your OS into thinking you have 2 cores when essentially you are running one. It prioritizes the tasks you are doing and focuses the processor on that task that it has prioritized first rather than any of the background processes or lesser prioritized tasks.

dual core will be worth it. ask your neighbor about the Pentium D 805 if you want a cheap dual core processor. Go find a good overclocking board and overclock it. or you can wait for conroe (july 23rd) and buy your system then. look at www.xtremesystems.org for conroe info, click forums and intel.

 

[Arcygenical]

Eh, Conroe is the sweet spot for performance, but many of the conroe-enabled boards are still quite expensive. In a few weeks, AMD will be slashing the prices of the X2 Lineup, and coupled with a nice cheap board (Asrock Dual Sata2 939 is my recommendation) you can get great power for very little. Sticking with Intel, an 805, coupled with a good board will produce nice overclocking results, and will serve you well over the coming year or two.

What is this machine primarily for? Gaming? If so, wait for Conroe and get a nice GPU, as games will always be more pressed for GPU power than CPU power. One thing's for certain, don't get a single core, that extra Physical Execution Unit makes a WORLD of difference (it equals much better multitasking, equal to that of the OS X mac platform IMO, yes, I said it) in regular day to day tasks. A real night and day difference. That 1 + 1/2 performance boost isn't correct, as you won't notice any speedups in single threaded applications, but run, let's say, winzip, limewire (legal downloads of course), azureus and maybe a game, and you'll really start to notice something.

If you're looking for best value/dollar go Conroe, if you're looking for a slightly underpowered system, go AMD, or the lower end Intel DC CPU and overclock it. Personally, if money wasn't an object, I'd trade my AMD for a Conroe, but it is... and the extra ~20% power just isn't worth the price.

 

[BriSleep]

Thanks all, you've given very good explanations. I think I will go with Conroe as this will be for gaming.

 

[StealthyFish]

good choice. I'm sure i'm speaking for every one when I say that I guarantee you will feel a difference with conroe.