A Preview of Intel's Centrino 2 Platformby Anand Lal Shimpi on July 15, 2008 12:00 AM EST
- Posted in
The Chipset: G45
The major component of Centrino 2, and a large part of the reason for its delay, is Intel's new GM45 chipset - the mobile variant of the desktop G45 chipset.
|Intel GMA X4500HD (GM45)||Intel GMA X3100 (GM965)|
|H.264 Decode Acceleration||Yes||No|
With 25% more shader processors and a 6.6% increase in clock speed, the GM45's integrated graphics is definitely a step up from the GM965 chipset, which was a part of the Santa Rosa Refresh.
As we mentioned earlier in this article, we couldn't get the hardware video decode acceleration working properly on the GM45's integrated graphics. We used a beta version of Cyberlink's PowerDVD 8 Ultra (v8.0.1903.50) with support for GM45, but when playing back Gone Baby Gone we ran into some issues. CPU utilization did go down, but so did our frame rate. It was almost as if the video decode engine was only decoding half of the frames, the stuttering was that bad. Granted this is pre-release hardware, with pre-release drivers and a pre-release Blu-ray player, but going back to what we originally said - we expected a little more polish less than 30 days away from availability.
Blu-ray playback, hardware acceleration disabled
Blu-ray playback, hardware acceleration enabled - the CPU usage drops, but so does our frame rate
One interesting feature of the GM45 chipset is the ability to dynamically switch between integrated and discrete graphics, similar in nature to features announced by AMD and NVIDIA (e.g. NVIDIA's Hybrid Power). Unfortunately, our test system didn't have a discrete GPU so we couldn't test the feature ourselves. To make matters worse, Intel couldn't go into great detail about how the technology worked.
We're still waiting to find out how Intel's switchable graphics will work in practice
We were told that OEMs will either implement a hardware or a software switch to allow you to enable/disable discrete graphics, but we have no idea how it'll work. NVIDIA's implementation of a similar technology copies the frame buffer to main memory, using the integrated graphics core to output it to your display - Intel told us that its version doesn't work this way. Unfortunately we aren't sure if that means switching between integrated and discrete graphics will require a hardware reboot, or if it'll be possible to do so on the fly. We have more questions than answers here so it's better that we leave speculation alone and wait until it's something we can test ourselves.
Both the GM45 and its discrete graphics counterpart (PM45) support DDR2 and DDR3 memory, the latter being a newcomer to the mobile space. DDR2-667/800 and DDR3-800/1066 are both supported, although at the same data rate DDR3 should offer better battery life thanks to a lower operating voltage (1.5V vs. 1.8V). DDR3-667 support will eventually come with the release of SFF Centrino 2 platforms.