Posted in Mac , Apple , MacBook Pro , notebook , laptops , Mobile
What happens from here on out is what’s really interesting. Intel has already committed to moving the TDP of its mainstream parts from 35W – 45W down to 10 – 20W. Since the Air is the new mainstream Mac notebook, Apple has already made that move. The performance in this 10 – 20W segment is going to get much better over the next two years, particularly once Haswell arrives.
The Thunderbolt Display is the first sign of what’s to come. Moving IO controllers and expansion into the display, and potentially even moving discrete GPUs out of the notebook are all in store for us. Apple is really ahead of the curve here, but it’s easy to imagine a future where laptops become a lot more like the new Air and shift to a couple high bandwidth ports instead of numerous lower bandwidth connections.
Perhaps I was being too aggressive in the prediction of a couple of high bandwidth ports. After all, the next-generation MacBook Pro with Retina Display features four such IO ports (2 x Thunderbolt and 2 x USB 3.0). But you get my point. Gigabit Ethernet and Firewire 800 are both gone. The discrete GPU is still present but I suspect even its days are numbered, at least inside the chassis. The personal computer as we knew it for so long, is changing.
The personal computer is getting thinner, lighter, more integrated and more appliance-like. The movement is no longer confined to just Apple either. The traditional PC OEMs are following suit. Even Microsoft has finally entered the PC hardware business, something it threatened to do for years but hadn’t until now. Distribution models will change, the lines between different form factors will continue to blur. What was once a mature industry is going through a significant transformation. It’s exciting but at the same time it makes me uneasy. When I first got into this industry everyone had stories of companies with great ideas that just didn’t make it. As we go through this revolution in computing I’m beginning to see, first hand, the very same.
Apple makes the bulk of its revenue from devices that don’t look like traditional personal computers. For the past couple of years I’ve been worried that it would wake up and decide the traditional Mac is a burden, and it should instead be in the business of strictly selling consumer devices. With its announcements two weeks ago in San Francisco, I can happily say that my fears haven’t come true. At least not yet.
It’s been a while since Apple did a really exciting MacBook Pro launch. Much to my surprise, even the move to Sandy Bridge, the first quad-core in a MacBook Pro, was done without even whispers of a press conference. Apple threw up the new products on its online store, shipped inventory to its retail outlets, updated the website and called it a day. Every iPhone and iPad announcement however was accompanied with much fanfare. The MacBook Pro seemed almost forgotten.
With its WWDC unveil however Apple took something that it had resigned to unexciting, dare I say uncool status, and made a huge deal about it. Two weeks ago Apple did the expected and offered relatively modest upgrades to all of its portable Macs, all while introducing something bold.
Apple calls it the MacBook Pro with Retina Display. You’ll see me refer to it as the next-gen MacBook Pro, Retina MacBook Pro, rMBP or some other permutation of these words.
After using it for the past two weeks I can honestly say it’s the best Mac Apple has ever built. And there’s a lot more to it than hardware.
If you were hoping for a 15-inch MacBook Air, that’s not what the rMBP is. Instead it is a far more portable 15-inch MacBook Pro. I have to admit I was a bit let down the first time I laid eyes on the next-gen MacBook Pro, it looks good but it doesn’t look all that different. The disappointment quickly faded as I actually picked up the machine and started carrying it around. It’s not ultra light, but man does it make the previous chassis feel dated.
While I never really liked lugging around the old MBP (and it always made me feel like the old fogey at tradeshows where everyone else had something 13-inches or smaller), carrying the rMBP is a pleasure by comparison. Pictures really don’t do it justice. The impressively thin display assembly or overall chassis thickness look neat in a photo but it’s not until you actually live with the rMBP that you can appreciate what Apple has done here. I carry around a 15-inch MacBook Pro because it’s my desktop, and as such it’s incredibly useful to have with me when I travel. For my personal usage model, the Retina MacBook Pro is perfect.
If your workload demands that you need the performance of a MacBook Pro and your lifestyle requires you to carry it around a lot, the reduction in thickness and weight alone will be worth the upgrade to the rMBP. If you spend most of your time stationary however, you’ll have to be sold on the display and internal characteristics alone. The bad news is if the design doesn’t get you, everything else will.
The problem with being on the forefront of design is every iteration is expected to significantly outdo the one before it. The unibody MacBook Pro design took build quality to a new level for Apple. By constructing all parts of the machine that you generally interact with out of the same piece of aluminum, Apple significantly reduced the amount of flex and creaks you’d encounter during normal use.
The next-gen MacBook Pro chassis doesn’t revolutionize the design, but it does make some significant evolutionary improvements. The most tangible impact as I’ve already mentioned is the reduction in size and weight of the machine. At its thickest part, the 13-inch MacBook Air is actually a little thicker than the 15-inch Retina MacBook Pro. Unlike the MacBook Air however, the rMBP does not feature a tapered design. Instead you get a constant thickness which is definitely reminiscent of the previous design.
The backlit keyboard and glass covered trackpad remain, although the key travel has been reduced somewhat – likely to help thin down the chassis. It’s not worse, just different in my opinion.
The reduction in thickness also comes at the expense of a missing optical drive and no mechanical storage. Once again Apple has opted to use its own custom form factor and custom SATA connector for the NAND based storage in the rMBP. You’ll hear no complaints from me on the move away from mechanical storage as I’ve been recommending SSDs as upgrades for the past few years. The battery continues to be integrated but it’s no longer easily user removable as the custom cells are now glued to the chassis. A few years down the road your rMBP will have to take a trip to the Apple store (or a clever third party service center) to get its battery replaced.
The MacBook Pro with Retina Display, Image Courtesy iFixit
This is the first Pro appliance that Apple has ever produced. The CPU, GPU, DRAM, battery, display and, for now, the SSD are either non-removable or at least not user-upgradeable. On a $499 iPad that’s one thing, but on a $2199 professional notebook that’s a completely different matter. I can even make an exception for the MacBook Air as it is more of a consumer device, where computing needs have largely slowed down over the past several years. But for a professional machine, to have such a fixed configuration seems very worrisome.
|MacBook Pro with Retina Display Comparison|
|15-inch Mid 2012 MacBook Pro||MacBook Pro with Retina Display|
|Dimensions||0.95 H x 14.35 W x 9.82″ D||0.71 H x 14.13 W x 9.73″ D|
|Weight||5.6 lbs (2.54 kg)||4.46 lbs (2.02 kg)|
|CPU||Core i7-3615QM||Core i7-3720QM||Core i7-3615QM|
|Base CPU Clock||2.3GHz||2.6GHz||2.3GHz|
|Max CPU Turbo||3.3GHz||3.6GHz||3.3GHz|
|GPU||Intel HD 4000 + NVIDIA GeForce GT 650M|
|GPU Memory||512MB GDDR5||1GB GDDR5|
|System Memory||4GB DDR3-1600||8GB DDR3-1600||8GB DDR3L-1600|
|Primary Storage||500GB 5400RPM HDD||750GB 5400RPM HDD||256GB SSD|
|Display Resolution||1440 x 900||2880 x 1800|
|USB Ports||2 x USB 3.0|
|Other Ports||1 x Firewire 800, 1 x Audio Line in, 1 x Audio Line out, SDXC reader, Kensington Lock slot||SDXC reader, HDMI out, headphone out|
|Battery Capacity||77.5 Wh||95 Wh|
Apple has definitely made accommodations to make this unupgradeable reality more palatable. Sure the primary silicon is fixed, but all Retina MacBook Pro configurations ship with a minimum of 8GB of DDR3L-1600 memory. The only available upgrade is a move to 16GB, which will surely suit most needs for at least a few years to come (if not more).
The SSD is physically removable although there isn’t presently a source of 3rd party upgrades. I suspect we will see some in the future although there are always concerns about any legal claims to Apple’s unique form factor and physical interface. Apple’s concession here is it offers as much NAND as is physically possible today: up to 768GB if you’re willing to pay the handsome upgrade fee.
We’ve long given up on upgrading mobile CPUs or GPUs, and more recently abandoning the removable battery in favor of increasing capacity and reducing form factors is a trade off we’ve accepted as well. Apple has tried to help on the memory and SSD sides but the whole package is still very…fixed.
Despite all of this my only real complaint about Apple’s fixed configuration is the $2199 spec comes with too little storage by default. If I want to carelessly use my machine and not worry about regularly deleting unused files I find that I need 512GB of storage. At 256GB it’s too easy to run out of space, particularly if I’m on the road and dealing with lots of photos and videos. If you’re like me then you’re shoehorned into getting the $2799 configuration as there’s no way to just upgrade the size of the SSD in the $2199 model. And if you’re spending $2799 you might as well get the 16GB memory upgrade, if you can convince yourself that you’re not going to buy the Haswell version next year.
Retina MacBook Pro Silicon: One Big Happy Family
Powering the Retina Display MacBook Pro is Intel’s latest and greatest quad-core Core i7. A part of the new 22nm Ivy Bridge family the Intel silicon in the system is well done as always. The default configuration ships with a 2.3GHz quad-core offering, while the upgraded option is clocked at 2.6GHz. Apple offers one more upgrade at 2.7GHz while upping the L3 cache to 8MB. Since these are i7s all of them have Hyper Threading enabled, making the major difference between parts frequency and cache size in the case of the most upgraded part.
|Apple MacBook Pro with Retina Display CPU Comparison|
|2.3GHz quad-core||2.6GHz quad-core||2.7GHz quad-core|
|Intel Model||Core i7-3615QM||Intel Core i7-3720QM||Intel Core i7-3820QM|
|Base Clock Speed||2.3GHz||2.6GHz||2.7GHz|
|Max SC Turbo||3.3GHz||3.6GHz||3.7GHz|
|Max DC Turbo||3.2GHz||3.5GHz||3.6GHz|
|Max QC Turbo||3.1GHz||3.4GHz||3.5GHz|
|Processor Graphics||Intel HD 4000||Intel HD 4000||Intel HD 4000|
|GPU Clock (Base/Max)||650/1250MHz||650/1250MHz||650/1250MHz|
Turbo Boost is supported and active on all options. As always I verified its support in OS X as well as its functional operation:
889A refers to the max number of speed bins supported by Turbo Boost for 4, 3, 2 and 1 active core, respectively, in hex. For example, the 2.6GHz base clock of the Core i7 in my test system can turbo up a maximum of 8 bins with three/four cores active (2.6GHz + 800MHz = 3.4GHz), or 9 bins with 2 cores active (3.5GHz) or 10 bins (A in hex) with 1 core active (3.6GHz). Just as with previous mobile Macs, CPU clocks remain unchanged regardless of whether the system is running on AC or battery power.
All of the CPU options feature Intel’s HD 4000 graphics, which handles the majority of graphics duties unless you fire up an application that triggers the discrete GPU. All of the rMBPs feature NVIDIA’s GeForce GT 650M equipped with 1GB of GDDR5. Apple went aggressive on the Kepler implementation and ships a full 384 core GK107 in the rMBP. The GPU clock is set at a very aggressive 900MHz with a 1254MHz memory clock. I do appreciate that there’s no variance in GPU/memory configuration across all of the Retina MacBook Pro options, it greatly simplifies the purchasing experience.
Ports & Expansion
Port layout has been greatly simplified on the next-gen MacBook Pro. Along the left side there’s now a MagSafe 2 connector, two Thunderbolt ports, one USB 3.0 and one 1/8” jack for mic/headphones. The right side has the other USB 3.0 port, a full sized HDMI port and an SD card reader.
MagSafe 2 is a thinner version of Apple’s MagSafe connector, and it’s used on both the Retina MacBook Pro and the 2012 MacBook Airs. The rMBP still ships with the same 85W power adapter as before, but now with an integrated MagSafe 2 connector. In order to deal with the change in connector, Apple offers a $10 converter that allows you to plug MagSafe 1 power supplies into MagSafe 2 systems. All new Thunderbolt Displays shipping from here on out will include the MagSafe 2 converter.
The absence of an integrated Gigabit Ethernet port will surely bother some, but Apple offers a Thunderbolt to GigE adapter for $30 to accommodate. Since Thunderbolt effectively offers an external PCIe interface, there’s no performance loss if you go this route vs. the old integrated GigE connector. I was able to sustain nearly 930Mbps between the rMBP with the Thunderbolt GigE adapter and last year’s MBP:
At a price of $30 Apple is most certainly using Intel’s Port Ridge Thunderbolt controller, a cost effective single-channel TB controller without any support for DisplayPort passthrough.
USB 3.0 is provided courtesy of Intel’s 7-series chipset. Apple supports the USB Attached SCSI protocol which should allow for even better performance than what I’m showing below (with all of my focus on Thunderbolt I actually don’t have a 6Gbps UASP enabled USB 3.0 dock in house):
The King of All Notebook Displays
For years Apple has been shipping some of the best displays in consumer notebooks, but the MacBook Pro’s Retina Display is in a league of its own. While I never liked the phrase “painted on” in reference to the iPad and iPhone Retina Displays, that’s the best way I can describe the effect the MacBook Pro’s Retina Display has on me. Text really does look painted on. The effect is really the result of two things.
The first is Apple’s removal of its cover glass. LCD panels aren’t particularly attractive, they are ugly squares composed of two pieces of glass and a number of filters/polarizers. To hide the ugly edges, display makers wrap bezels around the display. Most people aren’t fond of bezels so next came a ton of effort to minimize bezel size. An alternative is to simply place a third piece of glass over the entire LCD assembly and make it look as if the bezel and LCD panel are integrated. This outermost layer is known as a cover glass and is what Apple uses on all of its glossy displays. If you’ve ever taken apart a Cinema/Thunderbolt Display or a newer iMac you’ll know that the cover glass is literally just a piece of glass that you have to remove with some suction cups.
The MacBook Pro’s Retina Display does away with the cover glass and instead uses a fairly unique LCD assembly. There are still two pieces of glass but the outermost glass is actually a different size and shape – it integrates a bezel. By integrating the bezel into the outermost glass in the LCD stack you get the same effect as a cover glass but without the added reflections it introduces.
You also limit the possibility of dust getting trapped between the cover glass and the LCD. The danger is that you no longer have a protective piece of glass in front of your expensive new LCD. If you scratch the display you’re scratching the LCD itself. While this has been true for conventional matte displays for a while, it’s worth mentioning if you’re used to Apple’s glossy displays where you did have that added security layer.
The Retina Display is also obviously an extremely high resolution panel at 2880 x 1800. Note that this is 44.6% more pixels than Apple’s 27-inch Thunderbolt Display, and 26.6% more pixels than the 30-inch panels that we’ve loved for so long – all in a 15.4-inch notebook display.
At 220 pixels per inch it’s easily the highest density consumer notebook panel shipping today. At normal viewing distances and even with my face closer than I’m comfortable putting it I simply cannot discern individual pixels.
It’s the combination of these two elements, the removal of the cover glass and the insanely high pixel density that makes everything from text to UI elements just look painted on the new Retina Display. And the effect is gorgeous. I’ve never seen a prettier panel and it’s actually ruined me for pretty much all other displays, notebook and desktop.
While I can appreciate the iPad’s Retina Display, the impact from the MacBook Pro’s display is even more significant. Perhaps it’s because I still spend so much time working on a standard, non-tablet display, but I’m far more excited about this display than anything else Apple has delivered under the Retina moniker.
It’s not just pixel density that Apple has to offer here. Similar to its Retina Displays in the iPhone and iPad, the MacBook Pro’s Retina panel ditches TN in favor of IPS technology. The result is an incredible improvement in viewing angles. On a notebook I don’t spend a lot of time viewing it from far left/right angles, although I see the benefit when I’ve got others huddled around my display. Here the panel performs admirably – you lose brightness at far left/right angles but there’s no perceivable color shift. In fact, the painted on effect is even more impressive at these far left/right viewing angles.
For a single user however the more impressive characteristic is just how good the display looks at vertically off-center angles. I wrote much of the initial parts of this review while on an airplane in coach, which with a 15-inch notebook on my lap means I’m going to be looking at the display at a weird angle to begin with. The thinner rMBP doesn’t do enough to make the airplane usage model any better if the person in front of you decides to recline, but the IPS panel does make the display perfectly usable at the off-center angle you’ll inevitably have to deal with.
The Retina Display in Numbers
I already published preliminary analysis of the Retina MacBook Pro’s display. In short brightness is down a bit, black levels are considerably improved and contrast as a result takes a huge step forward compared to previous models. My personal MacBook Pro used the anti-glare matte screen and the improvement in contrast ratio compared to that reference is over 50%.
Apple made no mention of impact to color accuracy or color gamut. It turns out that the omission was for good reason, the Retina Display offers no improvement along either vector. The numbers show a slight regression compared to last year’s panel but the difference is imperceivable.
Technically Apple’s use of the word Retina in reference to a display only refers to the inability for the human eye to resolve individual pixels at a specified distance (18-inches for the MacBook Pro). In practice however Apple has delivered tightly integrated IPS panels with wonderful performance characteristics as a part of the Retina brand. I do hope that for the years to come Apple does not compromise on these fronts.
To make the MacBook Pro’s Retina Display a reality Apple had to work with panel vendors to build the panels it wanted at a reasonable cost, as well as deliver the software necessary to support insanely high resolutions. There was another problem Apple faced in making the rMBP a reality: the display pipeline of the GPUs Apple wanted to use didn’t officially support scaling to the resolution Apple demanded of them. Let me explain.
All modern GPUs have fixed function scaling hardware that is used to efficiently scale between resolutions. A scaler either in your GPU or in your display panel is what lets you run non-native resolutions at full screen on your LCD (e.g. running 1680 x 1050 on a 1920 x 1080 panel). None of the GPUs used in the Retina Display MacBook Pro officially support fixed-function scaling of 3840 x 2400 or 3360 x 2100 to 2880 x 1800 however. Modern day GPUs are tested against 2560 x 1440 and 2560 x 1600, but not this particular 5MP resolution. Even 4K resolution support isn’t widespread among what’s available today. Rather than wait for updated hardware and/or validation, Apple took matters into its own hands and built its own GPU accelerated scaling routines for these higher resolutions. Fixed function hardware is almost always more efficient from a performance and power standpoint, which is why there’s some additional performance loss in these scaled resolution modes.
What’s even crazier is Apple wasn’t pleased with the difference in baseline filtering quality between the Intel HD 4000 and NVIDIA GeForce GT 650M GPUs. As the Retina Display MacBook Pro would have to regularly switch between GPUs, Apple wanted to ensure a consistently good experience regardless of which GPU was active. There are a lot of filtering operations at work when doing all of this resolution scaling, so rather than compromise user experience Apple simply wrote its own default filtering routines. Since you want your upscale and downscale quality to be identical, Apple had to roll its own implementation on both. Apple’s obsessive attention to detail really made it possible to pull all of this off. It’s just insane to think about.
All Flash Storage
As expected, the next-gen MacBook Pro ditches mechanical storage in favor of a MacBook Air style NAND + SSD controller on a custom PCB. Apple refers to this solution as all-flash storage.
Apple’s distinction between Solid State Drives (SSDs) and all-flash storage boils down to what form the storage comes in. If it’s a standard form factor device in a chassis, it’s a solid state drive. If it’s just NAND + controller on a PCB? Then it’s all-flash storage. I suspect it’s a nicer way of saying proprietary SSD but either way they are technically the same thing, just in different forms.
The Samsung PM830 based rMBP NAND flash storage card, image courtesy iFixit
My Retina MacBook Pro was the upgraded model with a 512GB SSD, featuring Samsung’s PM830 controller. This is the same controller as in the Samsung SSD 830, which I’ve long felt was the best pair for Mac users who wanted an SSD upgrade. I’m not sure if other Retina MBPs may come with Toshiba’s SandForce based drive instead. I have one of these drives in house for a review but that’ll have to wait until next week.
Although both the Samsung and Toshiba/SandForce controllers support full disk encryption, neither hardware based encryption is supported by OS X’s FileVault 2. When OS X encrypts your boot volume not all areas are encrypted (such as the recovery partition). While I know SandForce allegedly offers multiple encryption levels across a volume I’ve never seen either controller claim support for partially unencrypted volumes. In this case it looks like for Apple to take advantage of SSD controller based encryption it would need more flexible encryption support on the controller level. If I were an SSD controller vendor I’d be paying close attention to this requirement.
Both the Samsung and Toshiba controllers support 6Gbps SATA – as a result performance is significantly better compared to previous Apple branded SSDs. I borrowed a friend’s 2010 MacBook Pro which happened to have a Toshiba based SSD installed and ran it through our standard Iometer four-corners test suite. This was a well used drive and thus the performance is even worse than last year’s MacBook Airs. The improvement in performance is astounding:
The move to 6Gbps SATA is often associated with a huge bump in sequential transfer rates, but in this case Apple enjoys a significant increase in random speeds as well. Note that some of this improvement is going to be due to the fully populated configuration of the PM830 in the Retina MacBook Pro’s SSD, but that shouldn’t downplay the significance of the move to Samsung’s latest controller. The previous generation controller used last year just wasn’t very good, and the Toshiba alternative was even worse. This year, Apple finally has a good solid state story to tell.
How much of this are you going to be able to actually tell in day to day use of the system? The sequential transfer rates are most tangible when you are writing to or reading large files like movies to your drive. Obviously you need a source that’s fast enough to hit these speeds. Although USB 3.0 can come close you’re unlikely to have a USB 3.0 SSD that’s as fast as the internal drive. Moving large files between your internal SSD and Promise’s Pegasus R4/R6 is where you’ll really appreciate this performance.
The random access improvements are likely overkill for most normal uses. Things like program launches, compiling, web browsing, and any other normal application IO will depend on a mixture of random and sequential IO. The key is to have good enough random IO performance to avoid becoming a bottleneck. I can safely say that the numbers we see here are more than enough.
While previous Apple SSDs were nice only from a convenience standpoint, at least the Samsung option in the Retina MacBook Pro is what I’d recommend even if Apple didn’t bundle it with the machine.
We’ve already established that NVIDIA’s Kepler architecture is fast, but the GeForce GT 650M used in the rMBP is hardly the best NVIDIA has to offer. The result however is a significant improvement in performance over the Radeon HD 6750M used in the previous generation model.
|15-inch MacBook Pro Model||Mid 2010||Upgraded Early 2011||Upgraded Late 2011||Retina|
|GPU||GeForce GT 330M||Radeon HD 6750M||Radeon HD 6770M||GeForce GT 650M|
|Memory Bus||128-bit GDDR3||128-bit GDDR5||128-bit GDDR5||128-bit GDDR5|
|Memory Data Rate||1580MHz||3200MHz||3200MHz||5016MHz|
The GT 650M offers fewer “cores” compared to the 6750M and 6770M used in previous MacBook Pros, but likely better utilization of the available hardware. NVIDIA also clocks the cores much higher in the 650M, the result is a ~20% increase in theoretical raw compute power.
The memory bandwidth story is also better on Kepler. While both the GT 650M and the 67xxM feature a 128-bit GDDR5 interface, Apple clocked AMD’s memory interface at 800MHz compared to 1254MHz on Kepler. The resulting difference is 80.3GB/s of memory bandwidth vs. 51.2GB/s.
The real world impact is most noticeable at higher resolutions, thanks to the tremendous amount of memory bandwidth now available. The other benefit from the new GPU is obviously things run a lot cooler, which as I’ve already shown to considerably reduce thermal throttling under load.
At 1440 x 900 we actually see a regression compared to the 2011 models, but differences in the AMD and NVIDIA GPU drivers alone can account for the difference at this hardly GPU bound setting. Look at what happens once we crank up the resolution:
At 1680 x 1050 with 4X AA enabled we see a modest 11% increase in performance over last year’s MacBook Pro. As I established earlier however, the rMBP will be able to more consistently deliver this performance over an extended period of time.
What’s even more impressive is the 42.4 fps the GT 650M is able to deliver at the rMBP’s native 2880 x 1800 resolution. Even though I ran the test with AA enabled I’m pretty sure AA was automatically disabled. At 2880 x 1800 the rMBP is able to outperform the two year old MacBook Pro running at 1680 x 1050. How’s that for progress?
While the gains we’ve shown thus far have been modest at best, Starcraft 2 is a completely different story. Here for whatever reason the IVB + Kepler combination can be up to 2x the speed of last year’s models. I reran the tests both on the older and rMBP hardware to confirm, but the results were repeatable. The best explanation I have is Starcraft 2 is very stressful on both the CPU and GPU, so we could be seeing some thermal throttling on the older SNB + Turks hardware here.
Once again we see playable, although not entirely smooth frame rates at 2880 x 1800. I’ve also included a screenshot of SC2 at 2880 x 1800 below:
Although gaming options continue to be limited under OS X, Diablo 3 is available and finally performs well on the platform thanks to the latest patches. Diablo 3 performance is appreciably better on the GT 650M compared to last year’s 6750M. There’s no FRAPS equivalent under OS X (free advertising to the first eager dev to correct that) so I have to rely on general discussion of performance here. The GT 650M is fast enough to drive the rMBP’s 2880 x 1800 panel at native resolution at playable frame rates, around 18 fps on average. Connected to an external 2560 x 1440 display however the GT 650M is fast enough to deliver around 30 fps in Diablo 3. For what it’s worth, performance under Diablo 3 is far more consistent with the rMBP than with last year’s MacBook Pro. I suspect once again we’re seeing the effects of thermal throttling under heavy CPU/GPU load that has been well mitigated by the move to more power efficient silicon.