Looking for a project to keep you busy over the holiday period? Here’s how to build a great low end desktop system that could act as a media PC.

We have previously looked at the mobile version of AMD’s new Fusion APU, the A8-3500M. But this isn’t just a mobile processor, the first of the desktop variants have started hitting some retailers. While they can be a little hard to find, they make for a great low end desktop system and are especially good for media PCs.

Here we are going to take a look at the hardware you need to build one of these systems. While there isn’t anything drastically unfamiliar to those who are used to building their own PCs, both the APU and supporting chipset have some differences to that currently on offer from Intel. Keeping these in mind can ensure that the build process goes smoothly, and that you get the most from your hardware.

We have chosen some higher end products in our build, but simple substitution can drop the overall cost a lot. The A8-3850 APU is currently around $150 for a retail box, which comes with a heatsink. So it isn’t a dirt cheap solution like a Pentium or Athlon II based one; the overall price will be more in the realm of a low end Core i3 system.

One thing to keep in mind is that currently one needs to use Windows 7 to get the most out of Fusion. This is due in part to the inbuilt GPU’s heavy reliance on DirectX 11 but also a nod to the fact that Windows XP is so long in the tooth now that one can’t expect brand new technologies to continue to be supported on it.





At the time of writing there wasn’t much choice of APU. Being such a new product line AMD are starting off slow, with only two models being launched so far. Of these only one has landed in Australia, the A8-3850. This features a quad core CPU running at 2.9GHz and 400 Radeon Cores at 600MHz. The other model released is the lower end A6-3650, which has its four CPU cores running at 2.6GHz and 320 Radeon Cores running at 443MHz. The A6 hadn’t appeared in Australia at the time of writing but it was sitting at US$20 less than the A8 at US-based online retailers.

These boxed processors ship with their own heatsink. These APUs have a TDP of 100W but generally draw less power than that, and the stock heatsink will be just fine. We have gone with a larger third party heatsink for this build, largely because we do not have a retail APU but also to minimise fan noise in this media player focused build.




AMD has launched the A75 and A55 chipsets for its desktop APUs. Because the new CPU design necessitates a new socket (Socket FM1) the APUs aren’t compatible with existing AMD-based motherboards. At launch Gigabyte, ASUS, MSI and ASRock all had several models of motherboard using these chipsets, but don’t expect the kind of variety and high end offerings that are out there for Intel CPUs. At the moment AMD’s APUs are still a small part of the computing landscape. Variety will come down the track.

For this build we have gone for a MSI A75MA-G55 motherboard. This is a Micro-ATX offering, but there are full-sized ATX boards out there as well.  Most of the features are driven by the A75 chipset, so the features are largely the same between brands. This includes four native USB 3 ports, six SATA 6Gbps and a choice of D-Sub, DVI or HDMI outputs (other boards also include DisplayPort). In the case of the MSI A75MA-GD55 there are two USB 3 ports on the backplane and a motherboard header for two front panel ones.

This board has two x16 and one X4 PCI-E slots. This gives a modicum of expandability, allowing for a discrete graphics card and maybe a TV tuner or dedicated soundcard. Like all A75 boards it comes  with four DIMM slots.   




AMD’s APUs support up to DDR 1866, which requires a bit of tinkering to get working smoothly. It will also work with both DDR 1333 and DDR 1600, although it is best to check with your motherboard manufacturer to see which brands and models work with your system setup.

Because graphics processing is quite dependent on memory bandwidth, faster RAM will make a difference to gaming performance. If you do want to game then its worth searching out one of the faster memory speeds, but others will get by just fine on what fits into their budget. AMD recommends 4GB of memory for Fusion, which is what we consider the bare minimum for an enjoyable Windows 7 experience. Just remember that the APU uses a dual channel memory controller, so you’ll be wanting to buy dual channel kits rather than single sticks of RAM.




The 400 Radeon Cores inside the A8 APU are surprisingly powerful on their own, helping out with both video quality and providing enough grunt for some low-end 3D gaming. The APU also includes AMD’s UVD3 video decoding technology, which will ensure that everything from Xvid to 3D Blu-ray is decoded quickly and with minimal power draw.

With the A series APUs AMD has implemented a feature called Dual Graphics, which is the APU version of its Crossfire technology. Dual Graphics allows the APU to share graphics processing with a low end Radeon card, which makes for smoother, better looking games. The best card for this job is the $100 Radeon HD 6670 (higher end cards deliver enough performance on their own, and won’t work with dual graphics, thus negating the money you spent on an APU in the first place). Dual graphics also works with the Radeon HD 6570 and 6450 GPUs.




Unlike Intel’s current chipsets, all of the A75’s SATA ports support the latest SATA 6Gbps standard. If you are looking at getting an SSD then this comes into play, as you’ll want to get one that supports this higher speed connection. If you are just getting a standard HDD though don’t get too worried about finding a SATA 6Gbps one – the speed boost isn’t as noticeable for these as it is with SSDs.

MSI’s board uses UEFI instead of a BIOS so it will support booting from 3TB HDDs, but you’ll just want to check with the motherboard manufacturer if you want to go down this path. At the moment though 2TB is still the pricing sweet spot for drives so 3TB is something of a luxury.


Case and Power Supply


Choice of case will largely come down to personal choice. Keep in mind what type of motherboard you are using and get one that suits. For our media PC build we have gone with the somewhat luxurious Thermaltake DH 202 Touch, which comes with a remote and integrated touchscreen, but you can quite easily settle on a $50 budget case, depending on your needs. One thing to keep in mind is that because the Fusion APU is a relatively low-end product you don’t need a case designed around high airflow or extreme cooling.

One other side effect of the lower end nature of the A8 is that ridiculous wattage power supplies are actually not recommended for use with it. It tends not to provide the loading that 1000 Watt beasts need to keep running smoothly, and AMD recommends that you go with a high efficiency sub-750 Watt model. We have gone with a 500W Thermaltake TR2 PSU, which has an 80 plus bronze efficiency rating and will be ample for the hardware going into this system. As a rule of thumb try and get a reputable brand of PSU with at least an 80 Plus bronze rating – cheap and nasty no-name power supplies aren’t worth the hassle in our opinion.


The build

Here we have covered the choices that you need to make when configuring a Fusion based desktop PC. Next we’ll look at building and installing Windows 7 on the system. We’ll also get into the BIOS/UEFI settings needed to get things like Dual Graphics running smoothly as well as take a look at the new Vision Control Centre software.

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