NVIDIA's own documentation provides a glimpse into the inner workings of the new GeForce 9300 mGPU chipset. As the diagram below shows, it is a single chip solution. There's no North and Southbridge chips specifically as is the case with Intel's current chipsets. There's a 1333MHz FSB that communicates between the chipset and the processor, while the chipset has all the necessary functions required housed in one place. This aspect plus the more powerful built-in GPU are key reasons, why Apple went with NVIDIA's solution to create a more balanced platform - one that's much needed these days. Read on as we detail more key features of this recently introduced NVIDIA chipset:-
The feature list is quite similar to the existing GeForce 8 mGPU that NVIDIA has already introduced for the AMD platform. The Intel specific changes include an integrated dual channel memory controller that supports either DDR2-800 or DDR3-1333, which should give it some legs even as the market shifts from DDR2 to DDR3 memory. There are 20 lanes of PCI Express version 2.0, with 16 lanes dedicated naturally for a discrete graphics card should you choose that route. The remainder is divided as motherboard manufacturers see fit for other PCIe slots or onboard components.
Moving on to the next feature, there's the rather standard support for up to six SATA 3.0Gbps devices, with NVIDIA's MediaShield RAID (0, 1, 0+1, 5) technology. IDE devices will likely be supported by motherboard vendors with third-party solutions, as seems to be the norm nowadays. Other key features here are the impressive list of display output options, from the usual VGA analog to dual-link DVI to HDMI and even DisplayPort. Then there's the standard HD audio CODEC and native Gigabit LAN, which comes with NVIDIA's FirstPacket technology.
Most important for users is the integrated GPU onboard. NVIDIA says there are 16 stream processors, each running at 450MHz for the core and 1.2GHz for the shader processors. The GeForce 9400 mGPU meanwhile will be clocked at 580MHz/1.4GHz. Obviously, NVIDIA's proprietary technologies like Hybrid SLI is supported, with the GeForce 9300 mGPU capable of combining its graphical prowess with another similarly 'low-end' NVIDIA discrete GPU. In this case, only the GeForce 8400 GS and 8500 GT models are supported, which is a big red flag to what's the 'real' GPU integrated inside the 9300 (if you haven't guessed from the 16 stream processor count).
Also since there are stream processors within, CUDA is supported on the 9300 mGPU so if you're inclined to do your part, you can engage in Folding@home or even try the Badaboom media converter that's much touted by NVIDIA for speedy video transcoding. Also, Adobe's latest CS4 suite now supports GPU acceleration using NVIDIA GPUs and you should get slightly better performance out of the limited stream processing power on the 9300.
If you're more concerned about the HD video playback aspect, then you should be assured that the whole and latest PureVideo HD package is found onboard, including dual-stream decode acceleration (for picture-in-picture), image enhancements and post-processing. The GeForce 9300 mGPU also goes one step further than NVIDIA's own discrete GPUs by having full support for 24-bit 8-channel LPCM uncompressed audio through HDMI. This is something that surpasses AMD's much touted 780G chipset, though it is present in the ATI Radeon HD 4800 graphics card series.
A new addition that reflects NVIDIA's emphasis on GPU computing has to do with turning the integrated GPU on the 9300 into a dedicated PhysX processor, potentially improving the frame rates in games that support PhysX, like Unreal Tournament 3 and Ghost Recon: Advanced Warfighter 2. This only works when you pair the 9300 mGPU with a discrete lower mid-range graphics card like the GeForce 9400 and 9500 GT. This requirement is important as NVIDIA states that anything more powerful would adversely affect the overall performance instead. Currently, this is available for Windows Vista 32-bit.
Overall, it's quite a long list of interesting features, though not all will be useful for the typical mainstream user. They will no doubt enjoy the improved GPU performance. HTPC enthusiasts in particular have received quite a few goodies in the 9300 mGPU and it may well be a popular choice now. To see whether that's true, let us now turn to a suitably HTPC oriented board, the microATX ASUS P5N7A-VM that's featured on the following page.