iMac Core 2 Duo Benchmarks

[ImAlwaysRight]

I'm getting a 17" 2 ghz C2D iMac... Sounds exciting with all that speed! I don't know what to do with it! I guess my iTunes visualizations will be smoother, and I'll have the Dashboard ripple effect.

$1200K for a little eye candy? Woo-hoo! (Seriously, though, well worth the $ over an eMac G4 1GHz)

The overall score was 10% better in the new model

That's the bottom line, folks. Not a huge performance improvement, by any means. Anyone trading in a Yonah iMac for one of these Meroms has got to be nuts. If you are looking for any type of performance improvement, wait a year or two to upgrade.

 

[gnasher729]

now is the Xeon processor faster than the core 2 duo?

That is a rather pointless question since the Xeon processor in the MacPro _is_ a Core 2 Duo processor.

 

[gnasher729]

No, not at all.

An affinity mask sets the set of CPUs that can be scheduled. A job won't be run on another CPU, even if the assigned CPUs are at 100% and other idle CPUs are available.

And that, by the way, is why setting affinity is usually a bad idea. Let the system dynamically schedule across all available resources -- or you might have some CPUs very busy, and others idle.

Win2k3 also has "soft" affinity masks, which define a preferred set of CPUs. If all of the preferred CPUs are busy, and other CPUs are idle, then soft affinity allows the system to run the jobs on the idle CPUs - even though the idle CPUs aren't in the preferred affinity mask.

Another aspect of quad core systems like MacPro or future Kentfields: On these systems, two cores share one 4 MB cache. If an application runs on two threads, it can run on two cores on the same chip, or on two cores on different chips. Threads that run on the same chip can exchange data very quickly, because anything that is in one threads L2 cache is automatically in the other threads L2 cache, but both threads together have only 4 MB cache. Threads running on different chips cannot exchange data quickly; data that is exchanged needs to be transferred through main memory. However, _each_ chip has 4 MB cache, or 8 MB total.

In other words, some applications will run faster if using threads on the same chip, some will run faster if using threads on separate chip. It is quite hard for the OS to guess, but the application developer should have some idea.

 

[AidenShaw]

Aiden, it's just not like you to make a statement like this without adding the links...

http://www.spec.org/cpu2000/results/cfp2000.html

Note the Dell Precision Workstation 390 (Conroe) and the Precision Workstation 690 (Xeon 5100).

3 GHz Xeon - 2775
2.93 GHz Conroe Extreme - 2872

That "horrible buffered memory" is about a 3.5% handicap....at most. (The memory, chipsets, motherboards are all different.)

And one shouldn't say "but the FB-DIMMs are clocked faster" - the buffering is what enables the faster clock, as well as what adds the latency. The two tend to balance out, and the net result is that you can put 64 GiB of RAM on the Xeon - which you couldn't do without buffering!

 

[Konradx]

anyone know the iMac 24" or 20" Response time?

 

[miyamoto]

imac cpu swap

Some time back there was a post of someone swapping out a cpu in an Imac. Does anyone know if someone has managed to swap out the core 2 duo cpu yet? I assume they still arent soldered?

 

[zweigand]

The store is noisy, so it is hard to say. To me neither was making a sound.

My 24" is dead quiet. I haven't heard the fans spin up once. That's including multi-hour gaming sessions and Video encoding.