Power Consumption

Arguably one of the most important parts of a Home Theatre PC is power consumption because the beauty of an HTPC over any CE device is that it's entirely customisable to act as a multi-function platform. So, while it's not playing back your video and music, it can serve content to other PCs or alternatively sit there and downloading or recording something in the background.

In this respect many users will want to leave their Home Theatre PC on for most or all of the day, so very low idle power consumption is essential to keep your electricity bill in check.

The Intel CPUs still pip the AMD ones, even when we're using this new ultra low power chipset and 65nm Energy Efficient AMD CPUs. We included the 2.1GHz AMD Athlon X2 BE-2350 because it has a lower TDP of just 45W, just like the new AMD Athlon X2 4850e, but it's still cheaper and just as capable at playing back even very high bitrate, HDCP-encrypted 1080p Blu-ray content at under 40 percent CPU load!


The graph above doesn’t really tell the whole story for AMD’s 780G chipset, and this is something that we’re looking to change in the near future with some more advanced power consumption testing in future reviews. The reason we say this is because, while the other boards may sit at full load, barely able (or completely unable) to deliver smooth Blu-ray disc playback, the AMD Athlon X2 BE-2350/780G system sits at an average power consumption of just 78W when it’s playing back protected high-definition content.

Comparatively, in order to achieve smooth high-definition movie playback on the other boards, you would have to use a far more powerful Intel or AMD CPU, and that only results in one thing: increased power consumption. In effect, the AMD is by far the most power efficient solution, even though the graph above would suggest otherwise.

Value and Rounding Up

Without doubt the AMD 780G chipset is a revolution in performance for Home Theatre PCs – we finally have a platform that can playback everything we throw at it without compromises, regardless of the CPU used. It's strange to think that AMD is not only releasing a very inexpensive chipset but it also (inadvertently) encourages you to buy the cheapest, lowest power CPU possible because it'll still be more than capable thanks to the 780G's Unified Video Decoder (UVD) engine.

For those not wanting to bother with Blu-ray (or HD DVD), it'll still save you money because it affords lower power across the board on all common compression types: MPEG-2, H.264 and MPEG-4 (Divx/Xvid). But then again, a PC Blu-ray drive isn't that expensive any more – the only thing that's missing is full bitrate High-Definition 7.1 channel audio pass through. Currently PC users are still limited to DVD quality 5.1 channel Dolby Digital and DTS audio.

There are other features like Hybrid CrossFire, and the new 2.5GHz 45W AMD Athlon X2 4850e CPU which we will be reviewing separately at a later date, but as far as the chipset goes for use in an HTPC, this is the only option on the market to currently consider. Mind you, Nvidia will soon deliver its GeForce 8200 solution to market, and if Intel's G45 is anything like its G35 in terms of video playback quality, it could give the AMD 780G a run for its money. That said, if Intel’s G45-based boards share the same price difference as G35 versus 780G, the AMD solution should remain leagues ahead.

It's also important to remember the mobile aspect – even though the M780G isn't going to be available for a little while yet, the dedicated low power processor and very power efficient chipset will increase battery life massively. It’ll also allow OEMs to create inexpensive notebooks that can still to handle Blu-ray Disc playback at full HD resolutions.

This could give AMD considerable leverage, providing that is, it sorts out its mobile CPUs and makes the platform as good as Centrino (an unlikely event, it has to be said), or alternatively release a mobile north bridge supporting Core 2 CPUs – that’s something I can’t see happening though, because it goes against the AMD’s recent “platform advantage” marketing campaigns.

Blu-ray capable Home Theatre PC versus PS3?

So what's the cost against the next best thing: Sony’s PlayStation 3. Before we all harp on about the PS3 as a games console first and foremost, remember that the PS3 can't utilise DirectX 10 because it uses a GPU based on the G70 architecture. But then again, the PS3’s GPU is much more powerful than the AMD 780G IGP – and which would you prefer to game on?

Regardless of that though, the PS3 is regarded as the best (and certainly) the most popular Blu-ray player on the market if you believe Sony’s market research figures. The latest 40GB version will cost you just £279 but it will also gobble up around 280W of power at peak performance – that is significantly more than the AMD 780G system running at full load. And since Gigabyte’s AMD 780G motherboard is completely passively cooled, the noise level is limited to the heatsink, power supply and hard drive you use. As a testament to its genuine silence, I've used this motherboard in my own HTPC for the past few weeks and on more than one occasion I've had to look to see if the fans are moving, just to know if it's actually turned on/been left on.

Looking around at the prices for various components required to build a full-HD 1080p capable Blu-ray HTPC with a 780G motherboard, we came up with the following list:

• Motherboard: Gigabyte GA-MA78GM-S2H for £58.75
  
• CPU: AMD Athlon X2 4400+ 2.2GHz Energy Efficient at £42.50
  
• Blu-ray Drive: Pioneer’s BDC-202BK Black Dual Layer BD-ROM/DVD-RW Writer for just £100.07
  
• Memory: 2GB of DDR2 800MHz for just £31, although 1GB for £15 should suffice for a basic system.
  
• Hard Drive: 80GB Seagate 7200.11 Hard Drive for £26.59 – that’s twice the capacity of the 40GB PS3 at least, and the motherboard has more than enough SATA ports for future upgrades.
  
• Power Supply: Corsair VX450W for £39.95 – this is more than enough power and it’s from a manufacturer with an ever-growing reputation in the industry.

That's £298.86, not including a separate CPU cooler (should you want one) and case, although real men have their PCs splayed out over the floor, ad havok.

Lest not forget an Operating System and a copy of Cyberlink PowerDVD Ultra too, because you’ll need those to play back movies with the video acceleration features enabled. These will set you back £54 and £50 respectively. So yes, still more cash to part with, but it's significantly lower power and it's a more expansive and customisable system that can play back anything you want it to. Try getting a PS3 to recognise mkv files, for example. Cyberlink also gives its customers free updates to its software to include new features and compatibility, just like the PS3 does. And I guess Microsoft does the same too, but most would argue that’s to fix the many broken things in its latest OS.

The only two downsides are the lack of High-Definition sound pass-through, and a perfect score in HQV and HD HQV. But if the latter is an issue for you, a Radeon HD 3450 is just a £26 upgrade, and with that you’ll also get Hybrid CrossFire as a bonus too – we will be testing both the video quality and gaming performance of this combination at a later date.

With regards to the Gigabyte GA-MA78GM-S2H motherboard we used, while it's certainly inexpensive, the features are numerous and performance is really very good, the layout is unfortunately less than optimal. We'd expect a similar performance and core features from other boards, but different layouts and prices from the competition – our best advice is to just wait for a few weeks to see what arrives.

For the price we can't fault what AMD has done with its 780G chipset – it has a winning platform when you combine one of its Energy Efficient processors with an AMD 780G-based motherboard (and even a Radeon HD 3000-series graphics card if you need it). It's an absolute must buy for any home theatre enthusiast.

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