iMac 2-Core BEATS MacPro 4-Core?????

Frodo · Post by **Frodo** » Thu Sep 14, 2006 2:50 pm

I know-- it says **in some tests**.... but should that be the case in ANY tests? 2-core winning over 4-core? iMac over MacPro?

http://www.macworld.com/2006/09/firstlo ... lsrc=mwrss

HCMarkus · Post by **HCMarkus** » Thu Sep 14, 2006 3:10 pm

2.33 gHz beats 2.0? BFD. and I don't mean the VI. But note that multiprocessor aware apps fare much better, even on the slower Pro. I see all four of my cores working almost equally hard whilst I run DP.

Frodo · Post by **Frodo** » Thu Sep 14, 2006 3:54 pm

So again, it has more to do with software support than the amount of horsepower.

One would think that 4 cores would outperform 2 cores regardless. It really changes the answer when one asks what computer they should get if they want to run a particular app. Telling them that the 2-Core iMac would work better in those cases just comes as a surprise.

HCMarkus · Post by **HCMarkus** » Thu Sep 14, 2006 10:06 pm

If the software is multi-processor aware, then you are right, 4 cores should always beat 2, given roughly similar CPU speeds. However, a lot of software uses only a single processor/core. In such cases, processor speed trumps the number of processors. This would probably explain Macworld's posted results.

With the proliferation of multi-core computers, most software will eventually be MP aware.

eixb · Post by **eixb** » Tue Sep 19, 2006 7:46 am

a single thread running on a 2.5ghz single core processor will run faster than on a 2.0ghz dual core processor, because it essentially is running on a single 2.0ghz processor. the system can't split a thread between two processors, it can only run two *seperate* threads - one on each processor. if the software is capable of this, then everything will work as you expected. the trick is getting more than one thread running at once...which is where most software is heading now.

a dual core processor will typically outperform a single core processor of *equal* speed even running older software, because often the operating system is able to seperate UI threads & system tasks from the application's main thread and move them to the other processor.