The IGP Chronicles Part 1: Intel's G45 & Motherboard Roundup

Blu-ray Playback: Integrated Graphics Matters Again

We've already established that integrated graphics don't really matter for gaming. Those who are serious about games have a discrete card, those who aren't serious about games are either playing something that doesn't require 3D acceleration or plays well on everything. There is a small group that this doesn't apply to but I'd bet that you can fit the vast majority of users into one of the two aforementioned categories.

Over a decade ago, integrated graphics performance mattered for another very important reason - 2D performance. These days most all IGPs handle basic Windows performance just fine, so if you're not using integrated graphics for gaming, is there any reason to care about one over another?

Video playback emerged as a killer application for integrated graphics over the years, and with Blu-ray's emergence as the de facto high definition media standard the need for some minimum level of IGP performance was established.

CPU utilization during high bitrate Blu-ray playback is prohibitively high, thankfully we now have the transistor budget to include the entire H.264, VC1 and MPEG-2 decode pipeline on GPUs. As chipsets also shrunk in manufacturing process, the hardware Blu-ray acceleration functions also found their way into integrated graphics cores. It started with AMD and NVIDIA but now Intel is on-board.

G45 is Intel's first chipset to include support for full hardware H.264/MPEG-2/VC-1 decode acceleration, including the entire H.264 decode pipeline (CABAC/CAVLAC entropy decoding included). This support puts Intel's integrated graphics on-par with the feature set of ATI/NVIDIA IGPs as well.

It gets even better for home theater PC enthusiasts: G45 continues Intel's recent tradition of including support for 8-channel LPCM audio output over HDMI, a feature that has been around since the G965 days. NVIDIA supports 8-channel LPCM audio output over HDMI with its chipsets while AMD only offers 2-channel LPCM. I recently went through and explained exactly what this feature means but if you're looking to build a Blu-ray compatible HTPC with many speakers, it's a useful feature.

G45 Blu-ray Playback

The first incarnation of G45 had horrible Blu-ray playback issues, it just didn't work. Since then Intel has gone through numerous driver revisions and we're finally at the point where, with the latest drivers (15.11.2.1554) that Blu-ray acceleration just works. It's supremely disappointing that it took Intel this long to fix these issues but they are at least finally taken care of.

CPU utilization, as you would expect, goes down with hardware acceleration enabled.

With a Celeron Dual Core E1200 processor, CPU utilization while playing a Blu-ray movie goes down tremendously, especially during H.264 playback. On faster CPUs the end result is even more manageable:

The gap between the hardware accelerated G45 and its predecessor actually shrinks in the lighter load scenarios with a faster processor, but the difference when decoding H.264 is still impressive.

8-channel LPCM but no 24Hz Playback

Intel was extremely forward looking in its support of 8-channel LPCM audio over HDMI back on the G965 chipset; only within the past year have its competitors caught up. As I mentioned before, there's a thorough explanation of what 8-channel LPCM over HDMI means in our recent article here, but if you've got a 6 or 8 channel speaker setup and want to play Blu-ray movies, this feature is quite useful.

I tested 8-channel LPCM on G45 and, as expected, it just worked. Unfortunately there's still no 24bit playback support, which Intel is blaming on the ISVs for not supporting at this time - but technically there's no reason that it wouldn't work on G45 if there was proper driver/software support.