Faster than ever: Macworld Lab speed tests the mid-2011 iMacs

At a Glance
  • Apple 21.5-inch Core i5 iMac/2.7GHz (quad-core)

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  • Apple 27-inch Core i5 iMac/2.7GHz (quad-core)

    Macworld Rating
  • Apple 21.5-inch Core i5 iMac/2.5GHz (quad-core)

    Macworld Rating
  • Apple 27-inch Core i5 iMac/3.1GHz (quad-core)

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We’ve already shared the results of our benchmark tests for the $1999 27-inch 3.1GHz Core i5 iMac, one of four new iMac configurations released by Apple this week. We’ve had the chance to finish testing the remaining three standard-configuration models, with our results showing a significant boost for the new iMacs over the models they replace. However, not much differentiates the performance of the four new iMacs among each other.

The new entry-level iMac is a 21.5-inch, $1199 model with a 2.5GHz Core i5 quad core processor, a 500GB hard drive, and AMD Radeon HD 6750M graphics with 512MB of video memory. The other 21.5-inch iMac has a 2.7GHz Core i5 quad core processor, a 1TB hard drive, and AMD Radeon HD 6770M graphics with 512MB of video memory for $1499. A 27-inch iMac with otherwise identical specifications to the $1499 iMac costs $1699. And finally, the previously benchmarked 27-inch iMac is a $1999 system with a 3.1GHz Core i5 quad core processor, a 1TB hard drive, and AMD Radeon HD 6970M graphics with 1GB of video memory. All four systems run on Sandy Bridge processors from Intel.

Macworld Lab’s overall system performance test suite, Speedmark 6.5, showed these four new Sandy Bridge iMacs to be considerably faster than the systems they replace. The new $1199 21.5-inch, 2.5GHz Core i5 quad core iMac was nearly 24 percent faster overall than last year’s entry-level 21.5-inch iMac, which had a 3.06GHz Core i3 dual core processor. As you would expect, the new iMac showed the most improvement in applications that could take advantage of four processing cores. The new entry-level system was 37 percent faster in our Handbrake encoding test, 34 percent faster in our Cinebench CPU test, and 64 percent faster in MathematicaMark.

The new $1199 iMac was even faster than last year’s high-end standard configuration model, a 27-inch 2.8GHz Core i5 quad core iMac, by nearly 10 percent. In this case, the processor-intensive tests were very close, but the file duplication, zipping and unzipping a folder and opening a Word document in Pages were all considerably faster on the new $1199 iMac.

Compared to the 27-inch 3.2GHz Core i3 dual core iMac from last year, the new $1699 iMac was 25 percent faster. The older 3.2GHz Core i3 iMac also performed better than the new 2.7GHz Core i5 iMac in its file duplication and unzip tasks, but everything else was faster—sometimes much faster—on the new 2.7GHz system. Handbrake was 40 percent faster on the new model, Cinebench CPU tests were 37 percent faster, and MathematicaMark scored 70 percent higher.

iMac (Mid-2011) benchmarks

Speedmark 6.5 Score
21.5-inch iMac Core i5 2.5GHz 215
21.5-inch iMac Core i5 2.7GHz 223
27-inch iMac Core i5 2.7GHz 222
27-inch iMac Core i5 3.1GHz 227
21.5-inch iMac Core i3 3.06GHz (Mid 2010) 174
21.5-inch iMac Core i3 3.2GHz (Mid 2010) 179
27-inch iMac Core i3 3.2GHz (Mid 2010) 177
27-inch iMac Core i5 2.8GHz (Mid 2010) 196
27-inch iMac 2.93GHz Core i7 (BTO, Mid 2010) 225
27-inch iMac 3.6GHz Core i5 (BTO, Mid 2010) 199
21.5-inch iMac 3.06GHz Core 2 Duo (Late 2009) 129
27-inch iMac 2.66GHz Core i5 (Late 2009) 195
15-inch MacBook Pro 2.2GHz Core i7 (Early 2011) 206
Mac Pro 3.33GHz Xeon Westmere six-core (BTO, Mid 2010) 263

Higher scores are better. Reference models in italics. Best result in bold.

Surprisingly, when compared to each other, the new iMacs logged similar performance numbers. In fact, only 12 Speedmark points separate the entry-level $1199 21.5-inch 2.5GHz Core i5 iMac and the top-of-the-line $1999 27-inch 3.1GHz Core i5 iMac.

Looking at the new $1699 27-inch 2.7GHz Core i5 quad core iMac, we see that it outperforms the entry-level $1199 system by just 4 percent, overall. The close scores can be attributed to the 500GB hard drive in the $1199 model which was faster at file duplication and unzipping folders than the other three models with their 1TB hard drives. iMovie, iTunes, Photoshop, Handbrake, Cinebench, and Mathematica were faster on the $1699 system.

The new 27-inch 2.7GHz system—which uses the same processor, graphics and hard drive as the 21.5-inch 2.7GHz iMac—performed nearly identically to that model.

We initially completed all of our tests before Apple released the Mac OS X 10.6.7 Update for iMac and the iMac EFI Update 1.6. We retested with the updates installed, and found no difference in performance with our tests.

Speedmark 6.5 individual application test results:
New iMacs (Mid 2011)

Duplicate
1GB
File
Zip
2GB
folder
Unzip
2GB
folder
Pages '09
Open
Word Doc
21.5-inch iMac Core i5 2.5GHz 18 147 36 70
21.5-inch iMac Core i5 2.7GHz 20 134 47 65
27-inch iMac Core i5 2.7GHz 20 133 45 65
27-inch iMac Core i5 3.1GHz 20 144 48 70
21.5-inch iMac Core i3 3.06GHz (Mid 2010) 19 166 42 77
21.5-inch iMac Core i3 3.2GHz (Mid 2010) 19 160 42 67
27-inch iMac Core i3 3.2GHz (Mid 2010) 20 161 43 76
27-inch iMac Core i5 2.8GHz (Mid 2010) 21 170 44 76
27-inch iMac 2.93GHz Core i7 (BTO, Mid 2010) 17 157 36 71
27-inch iMac 3.6GHz Core i5 (BTO, Mid 2010) 17 140 36 65
21.5-inch iMac 3.06GHz Core 2 Duo (Late 2009) 20 177 40 85
27-inch iMac 2.66GHz Core i5 (Late 2009) 22 179 43 76
15-inch MacBook Pro 2.2GHz Core i7 (Early 2011) 23 159 50 76
Mac Pro 3.33GHz Xeon Westmere six-core
(BTO, Mid 2010)
18 148 26 62

Results are in seconds. Lower results are better. Reference models in italics. Best result in bold.

Speedmark 6.5 individual application test results:
New iMacs (Mid 2011)

iTunes 10
AAC to
MP3
encode
Import
movie
archive to
iMovie '09
iMovie '09
export to
iTunes 10
for iPhone
Call of
Duty 4
framerate
21.5-inch iMac Core i5 2.5GHz 83 76 55 86.3
21.5-inch iMac Core i5 2.7GHz 74 71 49 87.6
27-inch iMac Core i5 2.7GHz 75 72 53 88.1
27-inch iMac Core i5 3.1GHz 74 66 51 88.5
21.5-inch iMac Core i3 3.06GHz (Mid 2010) 95 103 69 78.3
21.5-inch iMac Core i3 3.2GHz (Mid 2010) 91 101 68 78.4
27-inch iMac Core i3 3.2GHz (Mid 2010) 91 100 68 78.2
27-inch iMac Core i5 2.8GHz (Mid 2010) 95 78 56 88.1
27-inch iMac 2.93GHz Core i7 (BTO, Mid 2010) 92 61 55 88.3
27-inch iMac 3.6GHz Core i5 (BTO, Mid 2010) 80 90 61 79.0
21.5-inch iMac 3.06GHz Core 2 Duo (Late 2009) 123 97 102 19.1
27-inch iMac 2.66GHz Core i5 (Late 2009) 101 82 60 87.5
15-inch MacBook Pro 2.2GHz Core i7 (Early 2011) 83 70 55 81
Mac Pro 3.33GHz Xeon Westmere six-core
(BTO, Mid 2010)
81 48 48 88.3

Call of Duty 4 results are based on framerate; higher results are better. All other test results in the above chart are in seconds; lower results are better. References models in italics. Best result in bold.

Speedmark 6.5 individual application test results:
New iMacs (Mid 2011)

iPhoto '09
200 JPEG
import
Photoshop
CS5 action
HandBrake
0.9.4
encode
Cinebench
R11.5
graphics
21.5-inch iMac Core i5 2.5GHz 32 54 254 36
21.5-inch iMac Core i5 2.7GHz 33 52 236 41.6
27-inch iMac Core i5 2.7GHz 33 52 236 40.2
27-inch iMac Core i5 3.1GHz 28 53 209 38.3
21.5-inch iMac Core i3 3.06GHz (Mid 2010) 35 60 405 25.4
21.5-inch iMac Core i3 3.2GHz (Mid 2010) 34 58 391 27.4
27-inch iMac Core i3 3.2GHz (Mid 2010) 35 59 392 27.3
27-inch iMac Core i5 2.8GHz (Mid 2010) 36 55 256 31.9
27-inch iMac 2.93GHz Core i7 (BTO, Mid 2010) 29 53 208 34.8
27-inch iMac 3.6GHz Core i5 (BTO, Mid 2010) 33 55 340 31.0
21.5-inch iMac 3.06GHz Core 2 Duo (Late 2009) 42 62 569 6.4
27-inch iMac 2.66GHz Core i5 (Late 2009) 38 57 267 30.7
15-inch MacBook Pro 2.2GHz Core i7 (Early 2011) 52 55 220 35
Mac Pro 3.33GHz Xeon Westmere six-core
(BTO, Mid 2010)
27 55 144 34

CineBench R11.5 Graphics results are a score; higher results are better. All other test results in the above chart are in seconds; lower results are better. Reference models in italics. Best result in bold.

Speedmark 6.5 individual application test results:
New iMacs (Mid 2011)

Cine-
bench
R11.5
CPU
Mathe-
matica
Mark 7
Parallels
World-
Bench
Multitask
test
Aperture
3 import
and
process
Multi-
tasking
21.5-inch iMac Core i5 2.5GHz 103 10.0 287 108 63
21.5-inch iMac Core i5 2.7GHz 96 10.7 262 104 61
27-inch iMac Core i5 2.7GHz 96 10.6 263 111 60
27-inch iMac Core i5 3.1GHz 85 11.7 247 107 58
21.5-inch iMac Core i3 3.06GHz (Mid 2010) 157 6.1 340 125 78
21.5-inch iMac Core i3 3.2GHz (Mid 2010) 152 6.3 333 121 75
27-inch iMac Core i3 3.2GHz (Mid 2010) 152 6.23 332 123 75
27-inch iMac Core i5 2.8GHz (Mid 2010) 108 10.1 290 118 65
27-inch iMac 2.93GHz Core i7 (BTO, Mid 2010) 77 12.5 282 108 62
27-inch iMac 3.6GHz Core i5 (BTO, Mid 2010) 130 7.0 293 109 72
21.5-inch iMac 3.06GHz Core 2 Duo (Late 2009) 229 4.3 355 137 88
27-inch iMac 2.66GHz Core i5 (Late 2009) 112 9.7 300 118 65
15-inch MacBook Pro 2.2GHz Core i7 (Early 2011) 81 11.4 278 118 61
Mac Pro 3.33GHz Xeon Westmere six-core
(BTO, Mid 2010)
48 19.2 253 101 59

MathematicaMark 7 results are scores; higher results are better. All other test results in the above chart are in seconds; lower results are better. Reference models in italics. Best result in bold.

How we tested. Speedmark 6.5 scores are relative to those of a 2.4GHz Core 2 Duo Mac mini (Mid 2010) with 2GB of RAM, which is assigned a score of 100. We duplicated a 1GB file, created a Zip archive in the Finder from the two 1GB files and then unzipped it. We converted 135 minutes of AAC audio files to MP3 using iTunes’ High Quality setting. In iMovie ’09, we imported a camera archive and exported it to iTunes using the Mobile Devices setting. We ran a Timedemo at 1024-by-768 with 4X anti-aliasing on in Call of Duty 4. We imported 200 JPEGs into iPhoto '09. The Photoshop Suite test is a set of 23 scripted tasks using a 50MB file. Photoshop’s memory was set to 70 percent and History was set to Minimum. For our multitasking test, we timed the Photoshop test again, but with the iTunes MP3 encoding and file compression tests running in the background. We used Handbrake to encode four chapters from a DVD previously ripped to the hard drive to H.264. We recorded how long it took to render a scene with multiprocessors in Cinebench and ran that application's OpenGL, frames per second test. We ran the Evaluate Notebook test in MathematicaMark 7. We ran the WorldBench 6 multitasking test on a Parallels 6 VM running Windows 7 Professional. We timed the import and processing time for 200 photos in Aperture.—Macworld Lab testing by James Galbraith, William Wang, and Mauricio Grijalva

Keep in mind we’ve only tested the standard configurations so far. The new iMacs offer several build-to-order options including faster processors and solid-state drives (either as a replacement for or complement to the main drive). That latter option, in particular, could lead to some performance swings; we plan on testing the build-to-order iMacs as soon as we finish reviewing the base models.

Check back soon for Macworld’s full review of the new line of iMacs, including more graphics tests.

[James Galbraith is Macworld’s lab director.]

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