Silicon: Dual-Core Only

The biggest disappointment to me personally with the 13-inch rMBP announcement was the lack of any quad-core CPU options. Although they carry the same Core i5/i7 branding as the chips offered in the 15-inch rMBP, these parts are strictly dual-core. With a smaller chassis, the amount of heat Apple's cooling solution can effectively dissipate goes down. While the thermal budget in the 15-inch rMBP was 45W, the move to a 13-inch chassis drops it to 35W. Thankfully, Intel does offer 35W quad-core CPUs, a first for Intel starting with the Ivy Bridge introduction. Unfortunately Apple didn't seem keen on using them. For starters, having a quad-core upgrade option would likely add complexity to the lineup, and secondly the 35W quad-core parts are cost prohibitive. At almost 70% more expensive than the dual-core Core i5 Apple used in the standard configuration 13-inch rMBP, I can see why Apple wouldn't want to throw a 35W quad-core CPU in for free. At the same time, I would've at least liked to see a build-to-order quad-core option.

13-inch MacBook Pro with Retina Display CPU Comparison
  2.5GHz dual-core 2.9GHz dual-core
Standard On 13-inch rMBP Optional Upgrade
Intel Model Core i5-3210M Core i7-3520M
Base Clock Speed 2.5GHz 2.9GHz
Max SC Turbo 3.1GHz 3.6GHz
Max DC Turbo 2.9GHz 3.4GHz
L3 Cache 3MB 4MB
AES-NI Yes Yes
TXT No Yes
VT-x Yes Yes
VT-d Yes Yes
TDP 35W 35W
Processor Graphics Intel HD 4000 Intel HD 4000
GPU Clock (Base/Max) 650/1100MHz 650/1250MHz

By default both configurations of the 13-inch rMBP come with an Intel Core i5 3210M. That puts base clock at 2.5GHz with max single core turbo at 3.1GHz. Max turbo with both cores active is 2.9GHz. Hyper Threading is enabled on the chip, which presents OS X with the ability to schedule to four logical cores despite there only being two physical cores on the CPU.

Apple offers a single BTO CPU upgrade to a Core i7 3520M. Frequencies go up with the i7 upgrade (2.9GHz base, 3.6GHz max), which can definitely come in handy in keeping the system feeling as snappy as possible. The shared L3 cache is also a bit larger on the 3520M (4MB vs. 3MB).

Both CPU options integrate Intel's HD 4000 graphics core. Base and turbo GPU clocks are nearly identical to the HD 4000 in the 15-inch model (650/1100MHz).


The 13-inch rMBP, image courtesy iFixit

The move to the smaller chassis also meant ditching the discrete GPU. Although Apple could have technically included a discrete GPU, it would've come at the cost of a smaller battery (dGPU needs more PCB area which would take real estate away from the battery). The loss of the discrete GPU isn't actually as big of a deal as you'd normally think. Intel's HD 4000, the only processor graphics option on the 13-inch rMBP, is clearly capable of driving a 5MP display since it does just that in the 15-inch rMBP. That very same GPU, running at similar clocks (1.1GHz vs. 1.25GHz max GPU turbo), only has to drive 4MP with the 13-inch rMBP.

The bigger issue with ditching the discrete GPU is gaming performance. Although Intel's processor graphics have come a long way since the days when it was unusable, we're still roughly two years out from Intel's graphics being what I'd consider desirable. Although it's possible to game on the 13-inch rMBP, most modern titles won't be able to post good frame rates on any reasonable resolution. Although the GeForce GT 650M in the 15-inch rMBP could actually drive some titles at the display's native resolution, the same really can't be said for Intel's HD 4000 in the 13-inch system.

I firmly believe that Apple designed the rMBPs with Haswell in mind, and the 13-inch model is the embodiment of that. With Haswell, the lack of a discrete GPU shouldn't matter as much although if you're not a gamer I'm not sure the lack of a dGPU is really an issue today either.

Introduction & Form Factor Perfection? Achieving Retina - Redux
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  • repoman27 - Tuesday, November 13, 2012 - link

    And just to further clarify, Thunderbolt does not really mux DP and PCIe signals, it takes the packets from both protocols and transports them via a common switching fabric, so that wording is slightly misleading. Reply
  • tipoo - Tuesday, November 13, 2012 - link

    In my time with these, I find there is just a bit of UI lag to most things compared to an Air or the regular Macbook Pros, most of the time it's hard to even notice unless they are side by side. The calender flip animation and sometimes the green button re-size are particularly painful, you can literally count out the frames on the former. On the 15" you can force it to use the dGPU on AC power which fixes that, but there is no fallback for the 13". Reply
  • tipoo - Tuesday, November 13, 2012 - link

    Speaking of which, if switching to the dGPU fixes some of the lag does that mean more of the rendering pipeline is given to the Nvidia chip unlike the HD4000, as otherwise that would put a hole in the single threaded performance theory? Reply
  • sputnik78 - Tuesday, November 13, 2012 - link

    "There's not much you can do here other than wait for faster hardware or buy the fastest CPU available on whatever system you're considering. "

    Yes there is. Use Firefox or Chrome.

    I could not believe the depth of detail in the investigation of the scrolling in Safari issue without the simple test to swap out with Firefox or Chrome and see how much of the problem is Safari rather than the OS/Hardware.

    With Firefox, you can enable and disable GPU accelerated UI as well, to see if that helps or hurts.

    My experience with all three browsers is that each can have various performance issues with some websites and situations, but that when one does, one of the others tends to be OK.
    Reply
  • MrCromulent - Tuesday, November 13, 2012 - link

    Firefox doesn't even have Retina support yet, does it? Last time I heard it was planned for version 18.

    Disabling hardware acceleration in Firefox would probably just result in even worse performance since it is enabled by default and the CPU single-thread performance is going to get even more maxed out otherwise.
    Reply
  • paravorheim - Tuesday, November 13, 2012 - link

    Dear Anand,

    you mentioned in both the Intel S3700 and 13" rMBP reviews that OS X did not respond well to high IO latency. Could you expand on what you meant by that? Or is the explanation too complicated to put into layman's terms?
    Reply
  • AmdInside - Tuesday, November 13, 2012 - link

    I don't see how this is a much better option for someone who travels a lot and uses it mainly for typing. I love my MBA and only wish would be that it had more RAM and IPS display. If i had to do it all over again, I think I would still buy the MBA over the rMBP. If I had more money than I knew what to do with, I guess I'd go with the rMBP though. Reply
  • thefizzle656 - Tuesday, November 13, 2012 - link

    IMO what is wrong with the 13" rMBP is not just that the word "Pro" doesn't at all describe the hardware specs and capabilities of the machine, but that it is so so overpriced for what you get. Even Apple Fanbois are have been criticizing Apple for the complete ripoff that the 13" rMBP is. Reply
  • spronkey - Tuesday, November 13, 2012 - link

    You know, I have to agree with those who say there's a bit of Apple bias going on here. So many important criteria here have been glossed over - remember the pricing of this machine puts it far out of reach for most 'consumers', who go and buy $500-700 dell machines. It's a high-end part for a high-end prosumer/professional.

    The bottom line is - 8GB of RAM as a maximum ceiling (note - my *2008* MacBook Pro had the same limit) is far too low, and Anand you of all people should know that in the usable life of this machine (lets say 3 years), that limit is going to be hit - especially when it's not uncommon for web browsers with media-heavy content to eat 2+GB. And the move to 64-bit for stuff like the Adobe creative suite, which is a common use case for this particular machine, will eat even more RAM. I'm running 8GB on my MBP at the moment and I max it out very frequently.

    I'm also not sure how you can recommend this over the 13" Air. It's much more expensive, the hardware is largley similar, performance isn't *that* much better, it doesn't offer anything in terms of upgradability other than Thunderbolt connectivity, and it's bigger and heavier. Not to mention in the real world, in 2012, it's a laggier experience.

    Now, lets imagine an alternate universe where Apple decided not to shave quite so much off the size of the previous 13" pro, and instead gave us a quad core i5/i7 and a couple of RAM slots. Perhaps even a dedicated GPU and a 2.5" bay. Now that would be an improvement. What we have here is an expensive Macbook Air with a pretty display for text, that makes almost everything else look awful.
    Reply
  • seapeople - Saturday, November 17, 2012 - link

    When will we stop the insanity with this complaint about memory. Times are different, memory requirements are not going to quadruple again in the next four years. The world is not gearing up for Microsoft Gargantuan 9 which will require 8GB of RAM to load the desktop. If anything the world is going more mobile, and memory requirements will likely stagnate. Consider than an Ipad has just one GB of RAM, and they are selling about as many of those as casual consumer PC's nowadays, and you can see where we're heading.

    Furthermore, any browser worth its salt that's pushing 2GB of RAM based on some standard media heavy tasks will drop that RAM in an instant without a huge user experience impact if you start nearing a system limit. It's just caching everything in sight because it sees that you have 16 GB of RAM; it doesn't mean your system would grind to a halt with only 8!
    Reply

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