21.5-inch iMac (Late 2013) Review: Iris Pro Driving an Accurate Display
by Anand Lal Shimpi on October 7, 2013 3:28 AM ESTCPU 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.
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.
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.
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 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.
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.
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.
There aren’t any surprises in our FCP-X test either.
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.
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Res1233 - Wednesday, October 30, 2013 - link
Mac OS X is the main reason I buy macs. I have a feeling that you are right about most mac users having no clue what they're buying, but I could go on for hours about the advantages of OS X (geek-wise). No, hackintoshes are not an option if you want any kind of reliability, so don't even go there. If you force me to, I will explain my reasoning in depth to practically anandtech-levels, but I'm not in the mood right now. Perhaps another time! :)tipoo - Monday, October 7, 2013 - link
What are the chances of the 13" Pro duo getting Iris Pro 5200? I'd really love that.Bob Todd - Monday, October 7, 2013 - link
Have they announced any dual core Iris Pro parts? I know the original SKU list just had them in the quads. I still assume the 13" rMBP will get the 28W HD 5100 (hopefully in base configuration, but there will probably be a lower spec i5 below that).Flunk - Monday, October 7, 2013 - link
It's unsure, a new part could be announced at any time. Intel has even made variants specifically for Apple before.tipoo - Monday, October 7, 2013 - link
It shouldn't have to be dual core to be in the 13" pros though. Intel has quads in the same TDP as the current duals in it. A quad core, with GT3e, that would make it an extremely tempting package for me.Sm0kes - Tuesday, October 8, 2013 - link
I think anything but GT3e in the 13'' Macbook Pro is going to be a disappointment at this point. How their 13'' "pro" machine has gone this long with sub-par integrated graphics is mind boggling. The move to a retina display really emphasized the weakness.I'd also venture a guess that cost is the real barrier, as opposed to TDP.
tipoo - Thursday, October 10, 2013 - link
Perhaps. Yeah, the 13" has been disappointing to me, I love the form factor, but hate the standard screen resolution, and the HD4000 is really stretched on the Retina. If it stays a dual core, I don't see a whole lot of appeal over the Macbook Air 13" either. To earn that pro name, it really should be a quad with higher end integrated graphics.Hrel - Monday, October 7, 2013 - link
"This is really no fault of Apple’s, but rather a frustrating side effect of Intel’s SKU segmentation strategy."So I take it I'm not the only one infuriated by the fact that Intel hasn't made Hyperthreading standard on all of it's CPU's.
I remember reading, on this site, that HT adds some insignificant amount of die area, like 5% or something, but is capable of adding up to 50% performance. (in theory). If that's the case the ONLY reason to not include it on EVERY CPU is to nickel and dime your customers. Except it should really be "$100" your customers since only the i7's have HT.
Isn't the physical capability of HT already on ALL cpu's? It just needs to be turned on in firmware right?
DanNeely - Monday, October 7, 2013 - link
With the exception of IIRC dual vs quad core dies and GT2 vs GT3 graphics almost everything that differs between CPUs in a generation is either binning or disabling components if too few dies with a segment non-functional are available for the lower bin.Intel could differentiate its product line without doing any segment disabling on the dies; but it would require several times as many different die designs which would require higher prices due to having to do several times as much validation. Instead we get features en/disabled with fuses or microcode because the cost of the 'wasted' die area is cheaper than the costs associated with validating additional die configurations.
Flunk - Monday, October 7, 2013 - link
Actually the GT2 is just a die-harvested GT3. Intel only have 2 and 4 core versions and crystalwell is an add-on die so there are essentially only 2 base dies, at least for consumers.I do agree about the hyper-threading, there is really no need to disable it. It's not like it really matters in consumer applications anyway.