The Best Sub-£100 CPU

AMD A6-3650

Manufacturer: AMD
UK price (as reviewed): £87.99 (inc VAT)
US price (as reviewed): $119.99 (ex tax)

AMD’s new FM1 processors hit the market with a bang; finally, it was possible to play games on a reasonable-sized monitor using integrated graphics. This was exciting both for enthusiasts and PC manufacturers, as it opened up the possibility of making tiny yet capable gaming machines. Much of the goodwill and excitement surrounding the A-series APUs was generated by the performance results of the flagship A8 processors, though, so we wanted to find out how one of the cheaper A6 processors would fare.

The key difference between the A8 and the A6 range is the potency of the on-board GPU. The Radeon HD 6530D that sits on the die of the A6-3650 sports only four SIMD engines, rather than the five found in A8 APUs, which means that the GPU has a total of 320 stream processors and 16 texture units. The HD 6530D also has a lower clock speed than the HD 6550D of A8 processors, at 443MHz rather than 600MHz.

The CPU portion of the APU is functionally identical to that of AMD’s A8 processors (four cores and 4MB L3 cache), but it runs at a reduced 2.6GHz clock speed. Intriguingly, the A6-3650 also has the same 100W TDP as the A8-3850, despite having a lesser GPU and a lower CPU clock speed.

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The APU’s four physical cores helped it to perform well in Cinebench 11.5, as it scored the third-highest stock-speed score of 3.08. The £85 processor fared less well in our Media Benchmarks, however, scoring a particularly poor 856 points in our image editing test and an overall score of 1,008. This placed it very close to the bottom of the table.

The A6-3650 also failed to provide playable frame rates in any of our test games, although it’s worth pointing out that we were running both games at high settings (albeit with no AA), and that dropping these settings would probably result in playable frame rates. Performance with a discrete GPU installed in the system proved to be good in Bad Company 2, but poorer than cheaper but higher-frequency processors such as the Phenom II X2 560 BE in Arma II.

Overclocking A-series APUs is tricky but we were able to push the A6-3650 to 3GHz using a Reference Clock of 115MHz and its default CPU multiplier of 26x. This required a vcore of 1.542V and a CPU/NB of 1.23V. We saw an appreciable performance bump at these speeds; its result in our Media Benchmarks increased by 169 points to 1,177, and we saw an improvement of 2-5fps in our game testing too, both with and without a discrete GPU. However, the more powerful A8-3850 costs only £15 more, and is a much better buy.

Specifications

• Frequency 2.6GHz
  
• Core Husky
  
• GPU HD 6530D
  
• Number of cores 4 x physical
  
• Cache L1: 4 x 128KB, L2: 4 x 1MB
  
• Packaging Socket FM1
  
• Thermal design power (TDP) 100W