Building an AMD A8-3870K Llano APU System For Under $300

The Processor, Motherboard and Memory

One of the best bangs for your buck these days is an AMD Llano APU. AMD has been slashing prices on these processors and just last week slashed the price of the AMD A8-3870K down to just $101. These Accelerated Processing Units (APUs) are aimed at entry level to mainstream systems and is perfect to power our mainstream build.

The AMD A8-3870K Black Edition is a quad-core processor that runs at 3.0GHz and has a 100W power rating. The AMD A8-3870K has 4MB L2 cache and has a Radeon HD 6550D GPU for great 3D graphics performance. This GPU has 400 Radeon (shader) cores with that run 600MHz. This processor is also multiplier unlocked, hence the Black Edition name, for easier overclocking.

The AMD A8-3870K Black Edition retail boxed processor comes with a CPU cooler. As you can see from the screen shot above the CPU cooler is rather small and comes with thermal compound already applied to the base of the cooler. All you need to do is seat the processor in the socket and pop on the CPU cooler and secure it with the one lever! Before you do that you need to have a motherboard!

To power this system we went with the Gigabyte A55M-DS2 motherboard. When this board came out in 2011 it used to be $64.99 plus $8 shipping, but can now be found for just $49.99 shipped after rebate. We don’t need cutting edge features like USB 3.0 ports or SATA III 6Gbps hard drive connections, so the AMD A55 chipset and the Gigabyte A55M-DS2 was perfect for our build.

Just because this is a $50 motherboard don’t think you don’t get a ton of nice features. For example this is an Ultra Durable 4 board and features glass fabric PCB that protects the board from humidity damage. It also features all solid-state capacitors and comes with a pair of SATA cables.

The Gigabyte GA-A55M-DS2 rev 2.1 motherboard is a very small board that measures in at 225mm x 174mm. A standard mATX board is 244mm x 244mm, so Gigabyte went smaller than the standard here! As you can see from the photo above you have two DDR3 memory slots, four SATA II ports, one PCIe x16 slot, a PCIe x1 slot and a old school PCI slot. Along the left side of the board you have front audio header, another 4pin PWM fan header, COM header, a pair of USB 2.0 headers, the front panel headers and 4x SATA 3Gbps.

The rear I/O has two PS2 ports (1x mouse 1x keyboard), D-SUB (VGA), DVI-D, four USB 2.0 ports, Realtek Gigabit LAN and 3x audio jacks (Line In/Line Out/Microphone).

When it comes to memory we wanted to spend around $20 and found that you can get the Corsair XMS3 4GB (2x2GB) TW3X4G1333C9A G kit of memory for just $21.99 shipped after a $10 rebate. This dual channel memory kit runs at 1333MHz and features CL9 timings (9-9-9-24) at 1.50V. With a lifetime warranty and a $22 price tag it is hard to go wrong with a memory kit like this.

To install the memory and processor you just need to make sure they are lined up so the pins match and secure them in place.

The last step is to align the CPU cooler and to latch that down to the motherboards CPU socket tabs. Now we are ready to install everything into the case!