CPU Performance

I ran the entry level iMac through our normal OS X CPU test suite. I don't have a ton of Mac desktops in the database but I do have results for last year's 27-inch iMac that'll help put things in perspective. Also keep in mind that the 21.5-inch iMac came equipped with a HDD, while nearly everything else I'm comparing it to has an SSD inside.

Cinebench R11.5

Single threaded performance is about on par with an upgraded 13-inch Haswell MacBook Air, which is sort of insane when you think about it. The Core i7 upgrade in the 13-inch MBA can turbo up to 3.3GHz, compared to 3.2GHz with the entry-level iMac’s Core i5. The amount of L3 cache dedicated to a single core is actually the same between both parts (at 4MB). In the case of Cinebench, the 128MB L4 cache doesn’t seem to do much.

Cinebench R11.5

Multithreaded performance is obviously much better than what you’d get from a MacBook Air. You’ll notice the entry-level iMac’s performance here is actually quite similar to that of my old 2011 15-inch MacBook Pro. Although the Core i5-4570R has higher IPC and more TDP to work with, since it’s a desktop Core i5 it doesn’t support Hyper Threading and thus is only a 4 core/4 thread part. The Core i7 in my old MBP however is a 4 core/8 thread part, letting it make better use of each core’s execution resources in heavily threaded applications. This is really no fault of Apple’s, but rather a frustrating side effect of Intel’s SKU segmentation strategy.

iMovie '11 (Import + Optimize)

iMovie '11 (Export)

Looking at our iMovie test we see another 50% advantage comparing last year’s highest end 27-inch iMac configuration to the entry-level 21.5-inch model. The explanation boils down to lower max turbo frequencies and fewer number of simultaneous threads supported. There’s also the fact that I’m testing a HDD equipped system and comparing it to those with SSDs, but most of my OS X CPU test suite ends up being largely CPU bound with minimal impact from IO performance.

iPhoto 12MP RAW Import

iPhoto import performance runs pretty much in line with what we’ve seen thus far. The entry-level iMac is a good performer, but power users will definitely want to push for a faster CPU.

Adobe Lightroom 3 - Export Preset

Our Lightroom export test is perhaps the most interesting here. The gap between last year’s 3.4GHz Core i7 and the Crystalwell equipped Core i5-4570R is only 12%. My first thought was to attribute the difference to Crystalwell, but if we look at the gap vs. the 1.7GHz 2013 MacBook Air the iMac’s advantage isn’t really any different than under our iPhoto test. Instead what I believe we’re seeing here is yet another benchmark where Haswell’s architectural advantages shine.

Adobe Photoshop CS5 Performance

Performance in our Photoshop test is similarly good, with the entry-level iMac coming relatively close (within 20%) to the performance of a high-end 2012 27-inch iMac.

Final Cut Pro X - Import

There aren’t any surprises in our FCP-X test either.

Xcode - Build FireFox

I'm slowly amassing results in our Xcode test. What's interesting about the 21.5-inch iMac's performance here is just how inconsistent it was due to the HDD. Subsequent runs either gave me similar performance to what I'm reporting here, or much, much higher build times. If you needed a reason to opt for an SSD, this is a great one. Even looking at the best performance the iMac can deliver, you can see it's not tremendously quicker than the MacBook Air. With an SSD I'd expect to see far better numbers here.

Introduction & The CPU GPU Performance: Iris Pro in the Wild
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  • BiggieShady - Monday, October 7, 2013 - link

    Nice iris vs. geforce gaming comparison. I would love to see temperature and fan speed comparison.
  • name99 - Monday, October 7, 2013 - link

    It is crazy how cool these things run. I have a late 2012 27" i7 iMac and there is no part of it that is close to hot. The fan dumps hot air through a single hole which is very cleverly hidden below the hinge of the base so you don't even feel that unless you really look for it.
    Even when I've run the thing at max performance, having eight Mathematica kernels running in parallel for fifteen min or so, there's no obvious heating and no obvious fan noise.

    The difference with even as recent as the 2007 iMac (my last model) is night and day. Part is the much more efficient CPUs, part is also the much more efficient display.
  • odaiwai - Monday, October 7, 2013 - link

    How do you see the actual CPU current speed on an intel Mac? I've been looking for a utility to do that for ages.
  • abazigal - Monday, October 7, 2013 - link

    All this points to the possibility of a 15" retina macbook pro using only integrated graphics, which means comparable performance, with even longer battery life.

    Fun times ahead!
  • dylan522p - Monday, October 7, 2013 - link

    Probably only low end MBPr will do that this year, but next year if 6200 or whatever the Broadwell graphics are improved enough then very likely that could happen.
  • tipoo - Thursday, October 10, 2013 - link

    I hope they go the other way with it. GT3e for the 13" duo (especially for the retina, that would be a boon),and keep higher end discreet graphics in the larger models.
  • lefty2 - Monday, October 7, 2013 - link

    You forgot to mention that the fusion drive is not supported by Windows (if you are using bootcamp)
    "If you partition the drive, the new partition will not be part of the logical-volume group that Fusion Drive uses, so it will not benefit from the speed of the SSD"
    http://reviews.cnet.com/8301-13727_7-57549766-263/...
  • ananduser - Monday, October 7, 2013 - link

    Man that Iris looks a lot worse in reality than I expected it to be. You really have to crank down the resolution and details to get some decent gaming performance. Then again this is the base imac, it's got compromise written all over it.
  • CharonPDX - Monday, October 7, 2013 - link

    Correction: You state "By default all of the iMacs come with a 3.5” mechanical hard drive."

    iFixIt has shown that the 21.5" iMacs now come with 2.5" mechanical hard drives by default, not 3.5".
  • AlValentyn - Monday, October 7, 2013 - link

    Looks like my 2010 Mac Pro with 3.33 Hex core is still going strong. Finally going to add an SSD to it, and now I'm just waiting to see what AMD's R9 series GPU's are like.

    It is impressive to see how well these iMacs are doing these days though. :)

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