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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  • mikk - Monday, October 7, 2013 - link

    The difference to the 55W Macbook Iris Pro is so big in some tests that we can't explain it with a 10% lower GPU frequency. Anand once again failed to give us readers proper system infos. You have to learn that 8GB DDR3-1600 is not enough because it can be 2x4 GB in dualchannel or 1x8GB in singlechannel. Reply
  • Anand Lal Shimpi - Monday, October 7, 2013 - link

    All modern Macs ship in dual-channel mode.

    It's not just GPU frequency but turbo residency, which is lower on the 4570R for some reason.
    Reply
  • thunng8 - Monday, October 7, 2013 - link

    There is no 55W Macbook Iris Pro.

    It was an Intel supplied development board - not even in laptop form factor.
    Reply
  • coolhardware - Monday, October 7, 2013 - link

    Typo on last paragaph of page 4:
    'Doing *to* brings the price of the entry level 21.5-inch iMac up to $1499...'

    Interesting to see another look at Iris Pro. The current generation continues to leave me a bit disappointed, I had such high hopes for it. Here's hoping that Intel makes some significant strides in the next generation (i.e. signigicantly more than 10-15% improvement)
    Reply
  • Anand Lal Shimpi - Monday, October 7, 2013 - link

    Edited :)

    I suspect Broadwell will improve things once again, but Intel seems to be consistently one generation behind what we actually want for that generation.
    Reply
  • tipoo - Thursday, October 10, 2013 - link

    As soon as Broadwell comes out I'm sure we'll all be on the "wait for the actual new architecture" boat, such is technology :P

    But if Broadwell packs twice the EUs and the eDRAM bandwidth to feed it, that would be quite nice on the GPU side. I just hope they can improve the CPU side more.
    Reply
  • farhadd - Monday, October 7, 2013 - link

    The high end 27" imac is a 775M. Reply
  • kwrzesien - Monday, October 7, 2013 - link

    Anand, typo in the specs chart on the first page.

    The top 27" model graphics should be "NVIDIA GeForce GTX 775M (2GB GDDR5)". 775M instead of 755M.
    Reply
  • Anand Lal Shimpi - Monday, October 7, 2013 - link

    Edited, thank you! Reply
  • squirrelboy - Monday, October 7, 2013 - link

    i'm again baffled by this. who in their right minds would pay 1,3K for something with a low-end i5 and an iGPU? those specs belong in a $500 laptop. i really can't wrap my head around why anyone would do this. think of all the hardware you could get for that money! you'd be looking at an i5-4670k + gtx770 Reply

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