Fusion Power: AMD A8-3850 APU Tested
AMD has been touting its Accelerated Processing Units as the next big thing. Combining a quad-core CPU and a Radeon HD GPU into a single chip, these purportedly offer a superior blend of CPU and graphics performance to Intel's offerings. Join VR-Zone as we put AMD's very first A-series APU to the test.
AMD's acquisition of ATI back in 2006 was its first step towards integrating CPUs and GPUs. Since then AMD has been sounding the Fusion horn at regular intervals. At the start of this year we finally got the first APU, the low-power E-350 which was aimed at nettops and netbooks. The next logical step was to bring the APU to mainstream desktops and notebooks, the outcome of which is none other than Llano.
The CPU portion of Llano consists of four tweaked Stars cores. There is no L3 cache, but AMD increased the L2 cache size to 1MB per core instead. Add some other minor improvements and you squeeze 6% more performance out of what is, frankly, an ageing microarchitecture that dates all the way back to 2003. Performance should be very similar to a Athlon II x4 of similar clockspeed.
A-Series APU Comparison
|L2 Cache||4MB (1MB/core)|
|GPU||HD 6550D||HD 6530D|
AMD has four A-series APUs lined up, but only the A8-3850 and A6-3650 are currently priced and available. Both models are rated for 100W TDP and do not support Turbo Core. The A8-3850's CPU is clocked at a rather modest 2.9GHz, which is not surprising since there is also an onboard GPU to take into account. Turbo Core will only be used on the A8-3800 and A6-3600 to maximize single-threaded performance while still keeping within a 65W TDP.
Desktop Llano supports dual-channel memory at up to DDR3-1866 speed. This is significantly faster than Sandy Bridge's (official) DDR3-1333 support, and for good reason, as you'll see shortly. The A8 and A6 series will also be differentiated via integrated GPU performance. We'll take a look at that on the next page, but, first, some pictures of the real deal:
Llano uses a brand new CPU socket – the 905-pin Socket FM1. The gap in the center is faintly reminiscient of Socket 754 from days of yore. The good news is, heatsinks compatible with Socket AM2/AM3 will also work with FM1.