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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.
That's the point of the article. The Macworld article never considered processor useage. They said the new Intel Mac is "10-20% faster" without considering whether their benchmarks used the full capacity of the processor. They claimed that Jobs' statement that the new Mac was "2x faster" was wrong because they got smaller speedups. What this article s howed is that if you used Macworld's methodology (showing benchmark results without showing processor usage) you could argue that the quad-core G5 is only 14% faster than the Intel iMac running Quicktime. They're not saying that such a conclusion is correct, they're using it as an example to show what conclusions you can arrive at if you use Macworld's logic.
The basic problem was that Macworld's benchmarks were not CPU benchmarks and didn't make full use of the second core in the Intel Mac. The '2x' number Apple said was for the CPU --- even SJ mentioned that it doesn't mean apps will be 2x faster since the disks and everything else are the same. This article shows that in cases where the benchmark is CPU bound, the new Intel Mac can be almost twice as fast.
A deep unwavering belief is a sure sign you're missing something...
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)