MacWorld's iMac Core Duo Benchmarks Debunked?

madgunde writes "Looks like MacWorld magazine was a little premature in reporting that the new Apple iMac Core Duo doesn't live up to Apple's speed claims. The folks over at MacSpeedZone have done some performance testing of their own that debunks MacWorld's results and shows that the new iMac Core Duo DOES live up to the hype. Not only did the new iMac wipe the floor with the old model in their tests, but using MacWorld's own test methodology would allow MacSpeedZone to conclude that the new Intel iMac is almost as fast as a PowerMac Quad G5. " I see only one way to solve this: Give me one. I'll run WoW on it, and decide.

Comments

Nothing settled until Pro Apps...

[gsfprez]

i'm completley convinced that for using email, web browser, iPhoto, etc.. that the new iiMacs wipe the floor with comparably priced PPC macs.

what i want to know - and what holds me back from moving to an iiMac from my DP g5 1.8 - is

1. how they will perform when rendering with Compressor
2. how much faster is FCP when hooked up to similar disk packs (like cheap desktop FW400 raids)
3. Will i still be able to run background processing tasks like Compressor and handbrake yet get good foreground performance so i can email, websurf and get on with life while waiting for those 30-1 hour long tasks, instead of walking away from the machine, lest i get tempted to use it and really slow down the renders.
4. Will Aperture stop sucking performance wise?

Re:Nothing settled until Pro Apps...

[JohnsonJohnson]

what i want to know - and what holds me back from moving to an iiMac from my DP g5 1.8 - is

In general there's no reason to do so, the iMac Core Duo should be roughly equivalent in speed to a dual G5 system right now. Having the cores on a single chip gives it a slight advantage but the power dissipation aside the G5 is a very efficient chip and matches up well with the new Intel offerings on a clock for clock basis.

The Intel iMacs are not a Power Mac replacement, and shouldn't be considered as such, they bring roughly Power Mac levels of performance to the iMac and Powerbook lines, but do not surpass it.

More specifically...

1. how they will perform when rendering with Compressor

Probably about the same or even in favor of the G5. Compressor's code is highly dependent on the SIMD (SSE or Altivec) unit and the G5's Altivec unit, or the G4's for that matter is generally considered a better SIMD implementation on a general purpose microprocessor than SSE.

2. how much faster is FCP when hooked up to similar disk packs (like cheap desktop FW400 raids)

Again there will probably be no significant difference between the two platforms, since a the Core Duo is roughly twice as fast as the G5 iMac, but so is a dual G5.

3. Will i still be able to run background processing tasks like Compressor and handbrake yet get good foreground performance so i can email, websurf and get on with life while waiting for those 30-1 hour long tasks, instead of walking away from the machine, lest i get tempted to use it and really slow down the renders.

Multitasking performance is as much a function of the operating system's scheduler as the hardware. Again you would see little difference between the two machines. The G5's ability to hold more memory actually gives it a higher level of potential performance when the memory is maxed out than the iMac.

4. Will Aperture stop sucking performance wise?

Short answer, no. Aperture's performance is largely a function of Core Image which depends on the graphics card and system bus moreso than the CPU.

In general if you need an immediate speed upgrade a quad core G5 with a lot of memory is what you should purchase, otherwise wait for the workstation class Intel machines (MacMac? Following the PowerBook -> MacBook convention)

Re:WoW not such a good benchmarking program...

[God'sDuck]

It's time for Blizzard to step up to the plate and use the massive amounts of money we give them monthly to get some better servers. I'm not so good with math but 5,000,000 users paying 12 dollars a month is .... $60 million?

most of it goes to NPC salaries. [/deadpan]

Re:Jeez, guys...

[f0dder]

With over a million zealots hanging on your every word.

Depending on WoW's login server to give a Keynote presentation is not a wise decision.

Velocity Engine

[Anonymous Coward]

AltiVec! Velocity Engine!
I thought this was the best CPU technology?
Steve Jobs told me I had a super computer when I bought
my G3, G4 and G5.
My PowerPC processors were unique. It made me special. Anyone
can have an Intel processor. Even poor people. How is that exclusive?
I'm an upper middle class elitist snob. Why did Apple take away my bragging rights! Now I'm a technological nobody. I'm plain and boring again. For pete's sake, poor people can even buy IPODS now!!
I want my super computer back! Because I lack a personality and I have no soul what product can help? Please Steve Jobs tell me what to buy to get my soul back. What can I buy so that I feel whole again?
What about a Hybrid car, will that help me?

Re:What was MacWorld's flawed logic?

[rjstanford]

Its referring to tests that don't max out the CPU anyway, and therefore presumably have bottlenecks in some other part of the system. Here's a more rediculous example using the same theory:

Test: Compressing and sending a 16MB file over the network
iMac: 83 seconds (cpu usage 23%)
quad: 84 seconds (cpu usage 11%)

Wow! The iMac is faster than the quad! Of course, in reality it was working much harder to accomplish the same task (compressing at a bandwidth-limited speed). The articles point - and it is very poorly written, I will agree - is that this kind of test is crap.

The Macworld test used the same theories in the other direction. After all, if you perform a task that takes the old G5 iMac 20 seconds but uses 99% of its CPU, and takes the new intel iMac 19 seconds but only uses 45% of its total CPU power, I think you'd say that the iMac was more than 5% more powerful, right?

Admittedly if all you ever do is one task at a time, you wouldn't notice the difference. Considering that many people like to do multiple tasks - watching the recent keynote in a background window while doing some other work in a foreground window, for example - this is not an inconsequential point.

That brings up the example from the linked MacSpeedZone article:

Encoding one QuickTime movie:
intel dual core iMac: 97.02 seconds (87% CPU)
g5 quad core powermac: 84.85 seconds (42% CPU)
advantage g5: 14% faster

Encoding two QuickTime movies:
intel dual core iMac: 176.60 seconds (100% CPU)
g5 quad core powermac: 86.25 seconds (87% CPU)
advantage g5: 105% faster

Even that's a little misleading, since the quad still had spare processor bandwidth. This is why a lot of benchmark tests are designed to test each piece separately, spinning them up to 100%. Of course, real world tests are great as well - but only if your usage actually parallels those tests.