Driving the Retina Display: A Performance Discussion

As I mentioned earlier, there are quality implications of choosing the higher-than-best resolution options in OS X. At 1680 x 1050 and 1920 x 1200 the screen is drawn with 4x the number of pixels, elements are scaled appropriately, and the result is downscaled to 2880 x 1800. The quality impact is negligible however, especially if you actually need the added real estate. As you’d expect, there is also a performance penalty.

At the default setting, either Intel’s HD 4000 or NVIDIA’s GeForce GT 650M already have to render and display far more pixels than either GPU was ever intended to. At the 1680 and 1920 settings however the GPUs are doing more work than even their high-end desktop counterparts are used to. In writing this article it finally dawned on me exactly what has been happening at Intel over the past few years.

Steve Jobs set a path to bringing high resolution displays to all of Apple’s products, likely beginning several years ago. There was a period of time when Apple kept hiring ex-ATI/AMD Graphics CTOs, first Bob Drebin and then Raja Koduri (although less public, Apple also hired chief CPU architects from AMD and ARM among other companies - but that’s another story for another time). You typically hire smart GPU guys if you’re building a GPU, the alternative is to hire them if you need to be able to work with existing GPU vendors to deliver the performance necessary to fulfill your dreams of GPU dominance.

In 2007 Intel promised to deliver a 10x improvement in integrated graphics performance by 2010:

In 2009 Apple hired Drebin and Koduri.

In 2010 Intel announced that the curve had shifted. Instead of 10x by 2010 the number was now 25x. Intel’s ramp was accelerated, and it stopped providing updates on just how aggressive it would be in the future. Paul Otellini’s keynote from IDF 2010 gave us all a hint of what’s to come (emphasis mine):

But there has been a fundamental shift since 2007. Great graphics performance is required, but it isn't sufficient anymore. If you look at what users are demanding, they are demanding an increasingly good experience, robust experience, across the spectrum of visual computing. Users care about everything they see on the screen, not just 3D graphics. And so delivering a great visual experience requires media performance of all types: in games, in video playback, in video transcoding, in media editing, in 3D graphics, and in display. And Intel is committed to delivering leadership platforms in visual computing, not just in PCs, but across the continuum.

Otellini’s keynote would set the tone for the next few years of Intel’s evolution as a company. Even after this keynote Intel made a lot of adjustments to its roadmap, heavily influenced by Apple. Mobile SoCs got more aggressive on the graphics front as did their desktop/notebook counterparts.

At each IDF I kept hearing about how Apple was the biggest motivator behind Intel’s move into the GPU space, but I never really understood the connection until now. The driving factor wasn’t just the demands of current applications, but rather a dramatic increase in display resolution across the lineup. It’s why Apple has been at the forefront of GPU adoption in its iDevices, and it’s why Apple has been pushing Intel so very hard on the integrated graphics revolution. If there’s any one OEM we can thank for having a significant impact on Intel’s roadmap, it’s Apple. And it’s just getting started.

Sandy Bridge and Ivy Bridge were both good steps for Intel, but Haswell and Broadwell are the designs that Apple truly wanted. As fond as Apple has been of using discrete GPUs in notebooks, it would rather get rid of them if at all possible. For many SKUs Apple has already done so. Haswell and Broadwell will allow Apple to bring integration to even some of the Pro-level notebooks.

To be quite honest, the hardware in the rMBP isn’t enough to deliver a consistently smooth experience across all applications. At 2880 x 1800 most interactions are smooth but things like zooming windows or scrolling on certain web pages is clearly sub-30fps. At the higher scaled resolutions, since the GPU has to render as much as 9.2MP, even UI performance can be sluggish. There’s simply nothing that can be done at this point - Apple is pushing the limits of the hardware we have available today, far beyond what any other OEM has done. Future iterations of the Retina Display MacBook Pro will have faster hardware with embedded DRAM that will help mitigate this problem. But there are other limitations: many elements of screen drawing are still done on the CPU, and as largely serial architectures their ability to scale performance with dramatically higher resolutions is limited.

Some elements of drawing in Safari for example aren’t handled by the GPU. Quickly scrolling up and down on the AnandTech home page will peg one of the four IVB cores in the rMBP at 100%:

The GPU has an easy time with its part of the process but the CPU’s workload is borderline too much for a single core to handle. Throw a more complex website at it and things get bad quickly. Facebook combines a lot of compressed images with text - every single image is decompressed on the CPU before being handed off to the GPU. Combine that with other elements that are processed on the CPU and you get a recipe for choppy scrolling.

To quantify exactly what I was seeing I measured frame rate while scrolling as quickly as possible through my Facebook news feed in Safari on the rMBP as well as my 2011 15-inch High Res MacBook Pro. While last year’s MBP delivered anywhere from 46 - 60 fps during this test, the rMBP hovered around 20 fps (18 - 24 fps was the typical range).


Scrolling in Safari on a 2011, High Res MBP - 51 fps


Scrolling in Safari on the rMBP - 21 fps

Remember at 2880 x 1800 there are simply more pixels to push and more work to be done by both the CPU and the GPU. It’s even worse in those applications that have higher quality assets: the CPU now has to decode images at 4x the resolution of what it’s used to. Future CPUs will take this added workload into account, but it’ll take time to get there.

The good news is Mountain Lion provides some relief. At WWDC Apple mentioned the next version of Safari is ridiculously fast, but it wasn’t specific about why. It turns out that Safari leverages Core Animation in Mountain Lion and more GPU accelerated as a result. Facebook is still a challenge because of the mixture of CPU decoded images and a standard web page, but the experience is a bit better. Repeating the same test as above I measured anywhere from 20 - 30 fps while scrolling through Facebook on ML’s Safari.

Whereas I would consider the rMBP experience under Lion to be borderline unacceptable, everything is significantly better under Mountain Lion. Don’t expect buttery smoothness across the board, you’re still asking a lot of the CPU and GPU, but it’s a lot better.

Achieving Retina Boot Camp Behavior & Software Funniness
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  • darkcrayon - Tuesday, June 26, 2012 - link

    I hear you can work around that by not using that feature ;) Reply
  • Spunjji - Tuesday, June 26, 2012 - link

    this is lost deep in the comments, so I doubt it will get any form of response. Nonetheless, while I feel this review has covered the ground incredibly well, there were some sever omissions that limit its usefulness.

    Where, for instance, are the comparisons to laptops that are not made by Apple? It's all well and good telling me that this laptop is cooler than its predecessor, but the trouble is that I didn't buy the 15" MBP because it turns into an unpleasantly hot and noisy beast as soon as you start gaming on it. Based on the surface temperatures you give, it sounds like this is no better with the new model *relative to non-Mac laptops* and yet I have no real way of knowing this for sure. I'd really appreciate that comparison - the same goes for battery life. In my case I currently use an Alienware M17x and would absolutely love to trade to something lighter with similar capabilities, but I need to know what the usability caveats will be.

    I also feel that this site is asking us to take a lot on faith with regards to Thunderbolt. It's been a year and we can still only really attach storage to it outside of proprietary configurations, and even that doesn't work very well. We are also faced with the possibility that the first-gen tech will *never* work properly, yet it is still primarily mentioned as a good thing, with the rather horrible flaws pointed out deep within the bowls of a lengthy analysis.
    Reply
  • flatform - Tuesday, June 26, 2012 - link

    I am surprised not to see Anand commenting on the SEVERE problem that MOST users have with the Retina Displays -at least those mac users who are able to actually see a problem on their mac-. Advertising reasons maybe???

    Macbook Pro Retina -Plasma-TV-like(!!!!!)- Ghosting/Burn-in Issues
    https://discussions.apple.com/thread/4034848?start...

    IPad Retina issues: http://www.cultofmac.com/161495/new-ipads-retina-d...

    Plus, the only reason for apple not to put gigabit is that the port did not fit in the new slimmer UPPER profile, not the case itself, it would had ruined their design lines, that is all!!!!! The 2012 Vaio Z is much slimmer but has a gigabit port, strangely implemented yet still there. Having worked for years with macs, we ALWAYS had the same problem, when you needed that adpter you had bought, it just wasn't -for any reason- there.... humiliating experience in front of clients...

    having not normal SSD and especially no double slot configurable memory is probably just crap, 80% of laptops and desktops receive a hard drive and memory upgrade. just to shed off 100 Grams and 2mm of height?? 2009 Dell's Latitude Z600 was slimmer, 16inch displa, 2.0Kgs, yet had a normal hard drive and memory popped in.

    Anand, with a 4 core/8 Thread Machine 16GB is BARELY enough TODAY, to work with Photoshop, Premiere, After FX and a RAW developer open, and still have free memory so that after fx can use all Threads. And That did not include one or 2 3D applications that a compositor would usually run. 16GB is the minimum, 32GB is the choice for the Video Professional. With so many programs switching to GPU processing, you should really be careful when commenting on the power of any machine with a dedicated graphic card.

    For god's shake just wait and do not buy this crappy notebook. It is even more faulty than the first generation of 13inch Macbooks... wait at least 6 months for a proper revision, up to then Retina PC's will be available as well, with proper RETINA IPS displays with no burn-in issues and upgradeable parts.
    Reply
  • darkcrayon - Tuesday, June 26, 2012 - link

    I like how you mentioned the Vaio Z to bash the rMBP design, and then you went on to bash the rMBP for "limitations" that the Vaio Z also has (soldered RAM, though limited to 8GB, and more. Though off topic, your almost 3 month old iPad retina display problem is a nice touch, considering anyone with the problem could've gotten theres replaced for free. Please let us know which company is making millions of 260 ppi 10" screens with 100% perfect yields... Reply
  • flatform - Tuesday, June 26, 2012 - link

    Comment on Vaio Z was just to point out stupid decisions who take into consideration only the looks of the machine, not direct comparison of the two machines, which are not comparable. Apple could have kept the same upper profile and diminish the lower bevel part. But it would not LOOK as thin. Let's see how professional Photographers -which i work with- will welcome the lack of FW800 and the need to echange 2-3 adapters to do one job, or the presence of only 2 USB's is a total failure when working in production environment. I am a professional industrial designer and compositor, believe me i would really like rMBP to serve me properly (i have been complaining about low-res screens since 2006) but it simply cannot. Replacing for free is the most logical thing to do and does not replace the evident problem. The iPAD is not of topic, it is a High PPI, same technology display which suffers from similar problems, just as the Macbook Display.

    My comment was that if Anandtech was serious about this review -respecting the readers that is- it SHOULD have mentioned -in a separate page with the fullest possible technical description- the problem in a clean and straightforward way, even if their sample did not have it (have they checked for it?)

    When me moved from CRT's to TFT's (degrading our color reproduction, resolution and image quality) we did it because TFT;s had a hell less eyestrain, radiation, consumed less current and desk space. I cannot accepted that shedding off 150 grams (max) and 2mm of thickness from a WORKSTATION laptop is revolutionary and should force professionals to use adapters for the bluddy most used ports of their laptops, while depriving them from the most common upgrade in a notebook: memory and hard disk.

    As for the last question, please let us know which company has developed the screen for apple and how many months later the same screen would be available in pc's as well.

    Good thing Apple made the move, cause it has been FAR BEHIND in displays, (remember they where selling 1440x900 on 17" and 1280x800 on 15", then making it 1680x1050 and 1440x900 respectively, whereas a 1920x1200 15" screen was a common thing in mobile workstations) since they first brought a somewhat proper for graphic use display on their 2003 15" G4 Titanium. Workstation notebooks have IPS monitors for many years now.
    Reply
  • robco - Tuesday, June 26, 2012 - link

    Looking at the Googles, the news stories about the ghosting issues were posted today. Not something that likely would have been found before posting the review. This is a new display manufacturing process and there are going to be some mistakes. Never buy the first version, or at least the first production run, of any Apple product. This is one of the downsides to being an early adopter of almost any new technology. Apple tends to wait and collect data rather than acting rashly (see iPhone 4 fiasco). There isn't any data showing if this is a widespread problem, or only affecting a small percentage of units. But Apple will replace defective units.

    It took a little while, but third-party SSD upgrades are available for the MacBook Air. But on another note, would you expect *every* piece of equipment in your shop to be 100% user-upgradeable?

    Everyone whined when Apple ditched floppies, serial, ADB and SCSI. There were adapters and people, well they adapted as well. I'm sure some will just buy a Thunderbolt dock (a couple are coming in a few months) and hook up all their peripherals and then connect them (as well as gigabit Ethernet) to the laptop with a single cable. Some folks may even be OK with trying desperately to live with only 16GB of non-upgradeable memory and have a bit more room in their bags and a bit less weight to schlep around.

    But the beauty of the free market is that you get to vote with your pocketbook. If you're so terribly unhappy with the new rMBP, the old model, with new CPU and GPU upgrades) is still available. Show Apple your displeasure by sticking with the old design. Or by a fragile Sony laptop. Or a Dell Precision. Nobody is twisting your arm to make you buy this thing. Lots of other people will gladly accept the trade-offs and be happy with their lighter, thinner, quite powerful rMBPs...
    Reply
  • flatform - Tuesday, June 26, 2012 - link

    haha, good one "adapters that people adapted to" hahhaha. A good comment in general, covering most of the topics and dare i say most of the people in this page. Reply
  • wfolta - Tuesday, June 26, 2012 - link

    I stopped reading when you said "most users have", which is obviously not true. Reply
  • flatform - Thursday, June 28, 2012 - link

    Good thing to do, i am sure that made you wiser. Truth is a floating mean point of falsifications. (will not continue because you must have stopped reading already ;) Reply
  • pirloui - Thursday, June 28, 2012 - link

    "SEVERE problem that MOST"

    That would rather be "some" and "some".
    Reply

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