Graphics: A substantial bump

There are three new GPUs in the new iMacs: the AMD Radeon 6750M, 6770M, and 6970M. Unlike their desktop counterparts, the 6750M and 6770M are true 6000-series GPUs, and not just rebadges of the 5750 and 5770 (though, as always, making direct comparisons between desktop and mobile parts remains difficult).

On the entry-level iMac, the 256MB Mobility Radeon HD 4670 has been replaced by a 512MB Radeon HD 6750M – you get double the graphics memory, a switch from GDDR3 to GDDR5, DirectX 11, OpenGL 4.1, and OpenCL 1.1, as well as Eyefinity+ and UVD3 and the other Radeon 6000-series niceties. For gamers, this should substantially improve performance, especially if you’re interested in trying to game at the 21.5” iMac’s native 1920x1080 resolution.

Moving up the chain to higher-end models, the 512MB 6770M isn’t as big a step up from the previous generation’s 512MB Mobility Radeon 5670 – like the desktop cards, the 6770M is essentially a higher-clocked and gently tweaked revision of its previous-generation counterpart, and higher clocks are likewise all that separate it from the 6750M. You pick up UVD3, but a lot of the on-paper specs are the same. It’s still an improvement over the previous generation, but compared to the low end and (as we’ll see) the high end, it’s not as substantial.

And, finally, we’ve arrived at the high end 27” iMac, which gets a 1GB 6970M to replace last year’s 1GB Mobility Radeon 5750. The 5750 is more or less a midrange graphics part – the mobility 5600 and 5700 series GPUs all share the same core, codenamed Madison – but the 6970M is a true high-end part, complete with a 256-bit memory bus (compared to a 128-bit bus for the 5750) and more than double the shaders (960 in the 6970 versus 400 in the 5750). This, again, will drastically improve the new iMac’s utility as a gaming machine – the 6970M is much more capable of driving the 27” iMac’s 2560x1440 pixel display. Update: Further research has revealed that the 5750 that shipped in last year's iMac was in fact a rebadged member of the mobility 5800 series using the "Broadway" core instead of the "Madison" core used in Mobility 5600 and 5700 parts. The 5800 series has 800 shaders and not 400, so while the bump in the new 2011 iMac is still a decent one, it's not as monumental as previously reported.

For the 27” models with two Thunderbolt ports, the 6000-series GPUs will also enable the use of three displays simultaneously, which will be handy for the Final Cut and Photoshop junkies who often invest in the higher-end iMacs.


The last thing I want to talk about is the subtle factor looming over these refreshed computers: Lion.

OS X 10.7 is supposed to bring a lot of iOS features “back to the Mac” when it releases this summer, and since these Sandy Bridge Macs are going to be the first computers the new OS ships on, we’re seeing some preparation for it on the hardware end.

To drive the iOS inspired touch enabled features, each new iMac can come bundled with either the touch-enabled Magic Mouse or the Magic Trackpad at no extra cost (it’s your choice – the Magic Mouse is the default option). The vanilla Apple Mouse is still a selectable option, but will save you no money compared to its touch-enabled counterparts, which are more expensive at retail.

Apple is also beginning to push SSDs in its laptops to replicate the quick boot and shutdown times of iOS, and we’re beginning to see that in the new iMacs – while none of the computers include an SSD by default, you can configure all but the entry level to include a 256GB SSD as either the primary hard drive or a secondary drive. Characteristically, Apple hasn’t posted anything about the manufacturer of this drive or its controller – Apple uses Toshiba SSDs in the Sandy Bridge MacBook Pros, and recently switched to Samsung SSDs for the MacBook Airs, but there’s really no telling exactly what these iMacs are packing until it’s in your hands.

To replace the mechanical hard drive with a 256GB SSD costs a whopping $500 ($600 to get the SSD and keep the mechanical hard drive as well), though that’s not too far above the market price for an SSD at this capacity. Also note that, at this point, TRIM only seems to be enabled in OS X for SSDs direct from Apple – even if you can put in an SSD as an aftermarket upgrade, you may not be as satisfied with its performance. This may change in Lion, but we have no solid evidence to that effect.


With this refresh, Apple has done what Apple typically does: offer faster hardware in a similar physical package while maintaining price points across the board. Quad core processors and beefier dedicated GPUs make these better buys, relatively speaking, than last year’s models, but the iMac is still the iMac: a midrange-to-high-performance all-in-one with a high-quality display. Today’s upgrades do nothing to change the iMac lineup on a fundamental level.

That is to say, if you were in the market for an iMac already, congratulations! Today’s iMac is faster and more capable than yesterday’s iMac on all fronts. If an iMac isn’t what would best suit your purposes, though, today’s update won’t do much to change your mind unless you were looking for better gaming performance on the low and high ends.

For more about the nitty-gritty on the new iMac's performance and internals, keep an eye out for our in-depth review in the coming weeks.

Specs and CPUs
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  • psychobriggsy - Wednesday, May 4, 2011 - link

    Thunderbolt is a dual-channel (each channel is 10Gbps) bus. One of the channels can be DisplayPort. All implementations so far have a video signal on the cable, however it surely is possible to have two channels of PCIe instead, but it would probably need a special peripheral to make use of it. With graphics the 'special peripheral' for the second channel is one or two monitors.
  • nitro912gr - Tuesday, May 3, 2011 - link

    Are you guys serious?

    I read the comments and I see everyone compare the iMacs with a regular custom build desktop PC with windows...

    You miss the point here, that iMacs are All in ones and as of that is pointless to compare them with regular desktop systems.

    The real competitors to iMacs are the all in ones and the nettops and the only one who stand close in price but is somewhat weaker are the Sony Vaio Aio all in one desktops.

    Those All in one systems are more expensive to build than a part by part custom pc, you know that, they are more complicated. They have to take a serious amount of hardware, fit it on a monitor and plus it must function properly without overheating. The engineers are not just stuffing hardware, they design specific motherboards and specific parts who are not going to sale on large numbers.
    The parts we get for a custom pc can be cheaper, they are massive production hardware and not specialized.

    There is no way someone who wants the latest superGPU for games to get an iMac, it is obvious that he will also not get an all in one desktop at all.
    But some people need every inch of their space and need an all in one, or they have other reasons to believe that an all in one cover their needs.

    If apple ever make a regular desktop in mac pro case then OK, you do the direct compares and you say about overprice and whatever you want. Since that it is pointless to do that.
  • riverir - Wednesday, May 4, 2011 - link

  • edsib1 - Wednesday, May 4, 2011 - link

    Its a desktop so u compare it to other desktops.
  • nitro912gr - Wednesday, May 4, 2011 - link

    It is an all in one desktop so you compare it to the other all in one desktops, how much more this have to be explained to get the difference?
    The oven and the fridge are both kitchen devices but you don't compare each other...
  • edsib1 - Wednesday, May 4, 2011 - link

    On the one hand u want to say - "Oh look at the fabulous slim design" and use that a plus point when comparing to other desktops - and yet not take into account that slimness means you have to have average performance - by limiting what sort of desktop u want to compare it to.

    As to ur point - although trying to be clever - it doesnt work - a fridge and an oven dont perform the same tasks.
  • nitro912gr - Wednesday, May 4, 2011 - link

    Where the hell you jumped to that conclusion? I used a plus point comparing to other desktops?
    Are you dumb? It is not a performance comparison is a space save comparison and some people DO CARE about space because they don't have space.

    I don't believe that stupidity like the one you show here exist, so you must be trolling.

    I have nothing more to say, there are facts clearly stated above, the ones who have minds of their own can read and think what is right and what is trolling.
  • Focher - Tuesday, May 3, 2011 - link

    The technology will live on, but not in a discrete graphics product from Intel. It never came close to the performance of discrete GPUs from AMD or NVIDIA.

    So let's hope Apple doesn't use it, as a black screen doesn't make for a very good UI.
  • fluxtatic - Wednesday, May 4, 2011 - link

    One one hand, I'd love for Apple to finally bail on the PC market (we'll see how long this 'back to the Mac BS lasts) and embrace being the commodity-gadget company they have obviously become. If for no other reason than to have the Mactards finally stfu about how much better the holy hand of Jobs is with computers.

    On the other, I'd kind of like to see their market share grow to the point where it is worth the time of virus/spyware writers to write for Mac, to get the Mactards to stfu about how they're virus-proof. No, you aren't. It just isn't worth anyone's time to exploit systems with 10% worldwide marketshare.

    And to all the whiners complaining about how Windows is too much hassle - you're doing it wrong. I keep a real-time scanner on, clean junk out with CCleaner every once in a while, maybe scan with Spybot here and there, but I haven't had any sort of infection in over 15 years. You enjoy 'just using' your Mac. I'm going to do...whatever the hell I want, because there is software available that lets me do that. If I don't like this program, there's a competitor. I don't want to have to pay - that's fine, here's an open-source alternative. You enjoy your Garageband and iMovie. Aside from a small handful of pro applications, is there any software for Mac not written by Apple that doesn't suck hard? Not that all of Apple's software is much better in some cases...
  • nitro912gr - Wednesday, May 4, 2011 - link

    Skipping the delirium which make you look way more tard than all the mactards together, I inform you that there is no lack of software on mac platform and no, apple does not provide the only software available for macs and guess what, most of the open source software is available too!

    GImp, inkScape, Scribus, Blender and a lot of other open source apps are all available and ported to macOSX.
    Plus most of the windows software is ported to macs as well, but there is a lack of games. However steam made the big step forward for that allowing developers to move and sell their games easier to mac platform.

    So far I haven't found a software (expect some of the games I play) I have in my windows desktop, that is not available or have a good alternative for my macbook.
    So you are not just rude, you are misinformed too.

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