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AMD's Mac 3D Manager Discusses Graphics Cards & Drivers
September 30, 2011 | IMG Staff
Pages:123

IMG: Do you think an industry shift to developing more casual game titles, which are traditionally less demanding on graphics cards, will have an impact on card sales going forward? Will the development of high end graphics cards suffer?

CB: I can see the logic of your question, but it hasn't seemed that way to me. Since 1996 I've been tracking all of the hardware accelerated games on the Mac. My list is mostly compiled by reading www.insidemacgames.com :-). The trend I see is an almost explosive growth in Mac gaming over the past 3 years: 2009 saw 106 OpenGL accelerated titles ship on the Mac. In 2010, partly helped by the release of Steam, we saw over 175 OpenGL titles, and so far 2011 seems to be keeping the same pace. This year, with the launch of the Mac App Store and the release of Portal 2, Sims: Medieval, Dragon Age 2, Dirt 2, FIFA Soccer 12 and the upcoming release Arkham Asylum, is shaping up as one of the biggest ever for AAA titles on the Mac. Also, if anyone hasn't noticed, the machines Apple shipped in 2011 are kick-ass gaming systems. I remember when we were bringing up the 2011 MacBook Pro with 1GB VRAM, and we ran Dragon Age 2 at native res on a 27" panel (2560x1440) at high detail and 4x Multisampling, and it was perfectly playable. It was clear to us all that this was going to make a lot of people really happy. Similarly, when I ran performance comparisons between the 2010 iMacs (which had AMD Radeon HD 4xxx hardware) and the 2011 iMacs (which have AMD Radeon HD 5xxx hardware), I saw an average of 50% speedup across almost all games at max'ed settings. The 2010 models weren't slouches (I have the 27" model at home), but the 2011 units just cranked it up a notch. It felt good to deliver this kind of value year-over-year for Mac users.

IMG: Has the transition to Apple's new Lion OS been a smooth one? Do OS releases generally lead to a variety of graphical glitches that need to be tracked down?

CB: It's been really smooth, except I can't figure out how to scroll any of my windows down… Seriously, I know there have been a few graphics issues that people have run into, but overall I've been really happy with how few bugs slipped through. Every OS release involves some changes to the drivers, and the key thing to understand is that _everything_ that draws to the screen comes through the drivers: every window drag, every dock animation, every translucent drop down menu, every character added to a document, every triangle of every game. Given this fact, it's very easy for a change in the driver to break _everything_. The solution to this problem is: obsessive levels of testing. We have a test lab with just about every Mac that has shipped with AMD Radeon graphics. For every driver build, each machine runs an automated set of tests that includes 12 games at various quality settings and resolution and thousands of correctness tests. In 2010 our test farm completed 44,320 runs, including 7,179,840 timedemos. For 2011 the numbers are much higher. We browse these results looking for performance or correctness regressions and then are usually able to fix these quickly because we get such granular data on when the breakage occurred. We and Apple also do a huge amount of manual game and application testing. For Lion, we had a list of around 250 games and 50 apps that we cycled through continuously looking for any issues. I think the result of this "constant vigilance", is a pretty decent set of AMD drivers in Lion. And of course, we will keep working to improve them going forward.

IMG: Are Snow Leopard or Lion significantly different than previous versions of the OS in how they utilize the graphics card?

CB: Before SnowLeopard, Apple had already shipped Quartz Extreme, Expose, QuartzGL, Quartz Composer, Core Animation, etc, all of which heavily leverage the GPU in the system, so that part didn't change.  However, with SnowLeopard, Apple launched OpenCL and this involved a massive amount of work for AMD.  It's essentially another complete driver alongside 3D and Multimedia.  It's clear that the use of OpenCL by Apple and 3rd party developers is only going to grow over time, so this is a huge difference between SnowLeopard and Lion and the versions of MacOS X that came before.  In SnowLeopard, Apple also added full 64bit support which required some work in all the drivers.  It should come as no surprise that Apple is always working to improve the user experience and as a result every OS release has improved and optimized the interfaces between the Apple frameworks and the AMD plugin modules.  SnowLeopard was no exception and we did significant amounts of work to tune the drivers and make them work smoothly in the new OS. Now, for Lion Apple added Core Surface, Mission Control, Launchpad, fullscreen app support, and AMD support for accelerated H.264 playback.  The H.264 playback required loads of work to the AMD Multimedia drivers.  Likewise, for the 3D drivers the CoreSurface support was a big change that made possible much more streamlined sharing of rendered content between applications.  Finally, as I mentioned above, the biggest change for 3D in Lion was OpenGL 3.2 support, which included 16 new extensions supported on all the drivers from the AMD HD Radeon 2400 on up to the AMD HD Radeon 6970.



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