Apple plans to drop NVIDIA in favor of Intel's integrated graphics in its upcoming Sandy Bridge processors for use in Apple's 13" laptops, according to a report from CNET. Apple has so far resisted using Intel's current-generation processors in its smallest notebooks due to inferior graphics performance, lack of OpenCL support, and engineering constraints. CNET's sources claim, however, that Apple is impressed with the performance of Sandy Bridge's IGP, and that Intel plans to support OpenCL in some form, which would allow Apple to maintain OpenCL support across its entire computer line.
We decided to take a look at some of the technical aspects of Sandy Bridge and how it would fit in Apple's notebook strategy, and we identified a few aspects that might make Sandy Bridge a good fit for Apple's 13" notebooks. Low voltage variants likely won't ship until the second or third quarter next year, so don't expect a MacBook Air refresh before then—however, the same considerations apply for those models, as well.
Apple adopted Intel's Arrandale-class processors for its 15" and 17" MacBook Pro models. The Core i5 and Core i7 processors offer significant performance enhancements over the Core 2 Duo architecture, including hyperthreading and "Turbo Boost" technologies, among other architectural changes. However, Intel also integrated a GPU onto the processor, albeit on a separate die. This integrated graphics processor is (like most previous Intel IGP's) barely adequate for general use and lackluster for anything more demanding, like graphics applications or games. So Apple also added a discrete GPU and technology to switch between discrete and integrated graphics on the fly depending on the needs of running applications.
Apple has so far stuck to aging Core 2 Duos for its 13" MacBook Pro, entry-level 13" MacBook, and ultraportable MacBook Air models. Without room for a separate discrete GPU, Apple partnered with NVIDIA to produce the 320M—an updated version of the 9400M chipset with an integrated 48-core NVIDIA GPU. The combination of a Core 2 Duo processor and 320M gives Apple good overall performance in a small package, with low cost and low power requirements.
In particular, the 320M is more power efficient than the 9400M, using up to 40 percent less power while offering nearly twice the performance. Combined with battery and other power management improvements, Apple can boast of up to 10 hours of battery life for it's 13" notebooks, and between 5 and 7 hours for the latest MacBook Airs.
Sandy Bridge improves on Arrandale in two important aspects—both the IGP and the memory controller will be on-die with the CPU, offering performance improvements by dint of integrated cache access, faster communication between CPU and GPU, and more. And, by some accounts, the improved IGP should turn in performance at least twice as fast as current Intel IGPs.
CNET's sources say that this performance improvement—which should at least be on par with the performance of the 320M—is enough to satisfy Apple's basic graphical needs, if not its OpenCL requirement (more on that, below). With all of the typical northbridge chip integrated into the CPU package—and accompanied by a small I/O southbridge chip—a Sandy Bridge portable part should easily fit on the tiny logic boards of Apple's smallest portables. And with a TDP of 35W for both the CPU and GPU, it could well fit into Apple's power requirements—the current Core 2 Duos in the 13" MacBook Pros top out at 25W, and the TDP of NVIDIA's 320M is around 10-12W (based on what we know about the 9400M—neither NVIDIA nor Apple would confirm the exact figure).
In addition, Intel reportedly plans to support OpenCL on Sandy Bridge, in a roundabout way. Apple has embraced OpenCL by integrating support in to Mac OS X 10.6, and using NVIDIA controllers in its lower-end systems meant that all of Apple's shipping computers were compatible with the standard. The basic architecture of Intel's Sandy Bridge IGP can't support OpenCL functions at all—it's based on an archaic, specialized design that doesn't do GPGPU and will be replaced in Ivy Bridge later in 2011. But, Intel has been working on supporting OpenCL on its CPUs—with four simultaneous threads available on dual-core chips, it may be possible to execute OpenCL code acceptably fast on the CPU itself.
The licensing dispute between Intel and NVIDIA, which has so far prevented NVIDIA from building compatible controller chips for Intel's latest generation CPUs, could be coming to a close as the two companies are rumored to be in settlement talks. Such a settlement may allow NVIDIA to make compatible controller chips for newer Intel CPUs like Sandy Bridge, along with an integrated NVIDIA GPU. Or, if it's true that Apple plans to drop NVIDIA controllers—NVIDIA's CEO said in November the company didn't plan to build any new Intel-compatible chipsets—it may have made such compatibility a moot point anyway.
Assuming Apple is happy with the graphics performance of Sandy Bridge and OpenCL compatibility is addressed, the MacBook Air could see an update as early as the second quarter or as late as the third quarter of next year, depending on when small-outline, ULV Sandy Bridge variants are available in production quantities. We should have a better idea about this when Intel officially unveils Sandy Bridge chips at CES.
Whether Apple dumps NVIDIA for Intel's integrated graphics, or Intel and NVIDIA make nice enough that NVIDIA can build Apple something that is guaranteed OpenCL compatible, fans of Apple's most portable machines can expect a big performance upgrade coming next year.
