Apple Makes the Switch: iMac G5 vs. iMac Core Duo
by Anand Lal Shimpi on January 30, 2006 11:26 PM EST- Posted in
- Mac
iLife '06 Performance with iMovie HD
The next application that I looked at was iMovie HD, a part of the newly announced iLife '06. There are two primary focuses for performance in iMovie HD: video import speed (if you are dealing with a non-DV or non-iSight video source) and effect rendering speed. I focused on the latter, measuring the time that it takes to render various transitions and video effects in iMovie HD.
Note that all of the transitions and "Video FX" are single-threaded, so there was no performance difference on the iMac between running with two cores or one enabled.
First up are the transition rendering times. There are 15 transitions in iMovie HD that can be placed between two separate clips. I timed the amount of time that it took for the transition to be rendered upon inserting. Each transition was timed three times and the results were averaged - the average time is reported in the table below:
The Core Duo was slightly faster - the total for all of its transitions was about 8.5% lower than the iMac G5's time.
The bigger performance differences come when looking at the Video FX render times. These effects take anywhere from a few seconds, all the way up to multiple minutes to render, and can definitely bog down the creation of any movie project.
The sample above is almost all of the effects that you can perform in iMovie HD; the exception being all of the Quartz composer effects, which were left off in the interest of time. When the G5 and Core Duo are close, the G5 generally pulls ahead by a single digit percentage. However, when they aren't close, the Core Duo is usually ahead by at least 30%. If you average it all out, the performance advantage translates into about 11% in favor of the Core Duo. Once again, these tests are single-threaded, so there is no performance benefit due to the dual core nature of the Core Duo.
The next application that I looked at was iMovie HD, a part of the newly announced iLife '06. There are two primary focuses for performance in iMovie HD: video import speed (if you are dealing with a non-DV or non-iSight video source) and effect rendering speed. I focused on the latter, measuring the time that it takes to render various transitions and video effects in iMovie HD.
Note that all of the transitions and "Video FX" are single-threaded, so there was no performance difference on the iMac between running with two cores or one enabled.
First up are the transition rendering times. There are 15 transitions in iMovie HD that can be placed between two separate clips. I timed the amount of time that it took for the transition to be rendered upon inserting. Each transition was timed three times and the results were averaged - the average time is reported in the table below:
| iMovie HD Transition Rendering Performance in Seconds (Lower is Better) | iMac G5 1.9GHz | iMac Core Duo 1.83GHz |
| Billow | 5.36 | 4.14 |
| Circle Closing | 3.32 | 3.13 |
| Circle Opening | 3.41 | 3.09 |
| Cross Dissolve | 3.51 | 3.34 |
| Disintegrate | 6.14 | 4.73 |
| Fade In | 2.31 | 2.32 |
| Fade Out | 2.30 | 2.28 |
| Overlap | 3.25 | 3.25 |
| Push | 3.43 | 3.26 |
| Radial | 3.35 | 3.29 |
| Ripple | 6.74 | 5.32 |
| Scale Down | 3.73 | 3.53 |
| Warp Out | 3.58 | 3.91 |
| Wash In | 2.43 | 2.47 |
| Wash Out | 2.35 | 2.39 |
| Total | 55.21 | 50.47 |
The Core Duo was slightly faster - the total for all of its transitions was about 8.5% lower than the iMac G5's time.
The bigger performance differences come when looking at the Video FX render times. These effects take anywhere from a few seconds, all the way up to multiple minutes to render, and can definitely bog down the creation of any movie project.
| iMovie HD Video FX Rendering Performance in Seconds (Lower is Better) | iMac G5 1.9GHz | iMac Core Duo 1.83GHz |
| Adjust Colors | 75.62 | 48.62 |
| Aged Film | 30.43 | 32.44 |
| Black & White | 52.62 | 35.81 |
| Brightness & Contrast | 26.12 | 28.13 |
| Earthquake | 113.69 | 56.75 |
| Electricity | 78.47 | 54 |
| Fairy Dust | 151.69 | 58.63 |
| Fast/Slow/Reverse | 6.12 | 8.56 |
| Flash | 24.44 | 24.16 |
| Fog | 46.25 | 49.66 |
| Ghost Trails | 80.97 | 76.31 |
| Lens Flare | 61.12 | 46.22 |
| Letterbox | 26.94 | 28.75 |
| Mirror | 25.6 | 25.16 |
| N-Square | 31.13 | 32.63 |
| Rain | 45.6 | 39.75 |
| Sharpen | 35.75 | 43.25 |
The sample above is almost all of the effects that you can perform in iMovie HD; the exception being all of the Quartz composer effects, which were left off in the interest of time. When the G5 and Core Duo are close, the G5 generally pulls ahead by a single digit percentage. However, when they aren't close, the Core Duo is usually ahead by at least 30%. If you average it all out, the performance advantage translates into about 11% in favor of the Core Duo. Once again, these tests are single-threaded, so there is no performance benefit due to the dual core nature of the Core Duo.
Media Encoding Performance with iTunes and Quicktime
iLife '06 Performance with iPhoto, iDVD and iWeb
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snookie - Friday, February 3, 2006 - link
The article is very good but surprisingly makes the same mistake as so many other reviews which is to test with only 512MB of ram. The intel imac is a much better machine with more ram and it doesn't make sense to test it with the minimum amount. Also Universal apps are coming fast and furious on a daily basis. I've got 1.5 GB of ram in mine and lots of the little apps I use everyday are already UB and are nice and fast as is the OS and iLife apps. It won't be long before Windows runs on these as well as Linux with Red Hat promising support. Check out Bare Feats for some pretty nice benchmarks including games. Yes, Quake 4 will actually run at a decent speed as well as COD 2.http://www.barefeats.com/imcd.html">http://www.barefeats.com/imcd.html
csoto - Friday, February 3, 2006 - link
Your only complaints stem from poor choice of models/configuraitons. The 20" unit will provide the added resolution, and BTO options allow up to 2GB on the Core Duo and 2.5GB on the G5 (although a 2GB soDIMM is listed at >$1K!). This is like me complaining that my mini van doesn't have a navigation system, because I was too cheap to buy the model that came with it :)Also, your assertion that the Core Duo is a "public beta" is absurd. You had zero problems running applications. Word from those around me that are testing Core Duos is that for most applications, you don't even notice Rosetta. Pro Apps users would complain, but they're never early adopters, because their apps always lag at least a few months behind the latest platform (remember the "multiprocessor plug-in" that allowed Photoshop to limp along for so long before a "MP-native" version was released?). This is a solid platform transition, likely exceeding the fairly solid (albeit far more daunting for the day) transition from 680x0 to PPC.
Now if only VMWare would ship Workstation for Mac OS X, then I could ditch the Dell...
Charles
Furen - Sunday, February 5, 2006 - link
He says he already had an iMac so in order to compare the two I'm guessing he bought the closest-matching one possible. I would hardly do to have an 20" iMac compared with a 17" one in power consumption or running at a different native resolution. I do agree that the RAM limits the system insanely but he went for default specs rather you start improving all the draw backs each system has.The reason why he says this is like a public beta is not because Rosetta sucks or anything of the sort but because there are almost no universal binaries besides those shipped by Apple. Apple chose to bring these systems forwards (at first they had said the systems would come out mid '06, I believe) without having enough of a software base and that's a pretty big drawback.
jepapac - Wednesday, February 1, 2006 - link
I was just wondering if the graphics adapter on the iMac is upgradeable since it is using pciexpress. Does anyone know?aliasfox - Thursday, February 2, 2006 - link
I'm guessing its actually the laptop X1600 in the iMac, soldered onto the motherboard. Unfortunate, yes, but given the primary audience that the iMac is targeted at, I'm not surprised.Your average home user would rather buy a new $600-1000 box instead of dropping ~$500 for more RAM, a bigger hard drive, new graphics, and a faster processor.
Eug - Thursday, February 2, 2006 - link
Why? Previous iMacs used desktop GPU parts.
aliasfox - Thursday, February 2, 2006 - link
I read somewhere that the 9600 in the second generation iMac G5 was a laptop part, and I therefore assumed that since Apple used the same GPUs in the iMac that it used in PowerBooks (GeForce FX5200, Radeon 9600, X1600), it was sourcing the same parts for both lines.Also, I've never read about an integrated 9600 or FX5200 as a desktop part. I might be mistaken though.
nizzki - Tuesday, January 31, 2006 - link
Any idea which compilers apple has used for their apps? For example, for the PPC apps I assume apple uses the IBM compiler heavily optimized for PPC instead of GCC.If that is the case, with the intel compiler for osx is in beta, the current somewhat lackluster performance of the core duo might be skewed in PPC's favor. This would be further exacerbated if Apple used GCC to compile the macintel apps, since it is unlikely to be heavily optimized for the core duo architecture.
Commodus - Tuesday, January 31, 2006 - link
Just a heads-up, Anand: the Core Duo iMac is the first iMac model to support desktop spanning, not just mirroring. So if you want, you can hook up even a 23" Cinema Display and get a huge amount of extra workspace. I'd probably only do that with a 20" iMac and the 256 MB video memory option, though.ingoldsby - Tuesday, January 31, 2006 - link
Perhaps it's just me, but the non native apps I run seem to run at about the same speed as they natively ran on my G5. While the universal binaries run much faster.I would love to see this comparison revisited with a realistic amount of memory in the machine (ie. 1gb+) instead of limiting the machine to 512mb.