The Best Sub-£100 CPU

AMD Sempron 145

Manufacturer: AMD
UK price (as reviewed): £28.95 (inc VAT)
US price (as reviewed): $39.99 (ex tax)

At just £29, the AMD Sempron 145 is by far and away the cheapest processor in this group test. It boggles our minds a little that AMD can actually sell a full-size, current-socket processor for so little, given the production costs. The Sempron 145 is a single-core CPU based on the Sargas design, which is the same Regor die that you’ll find in the Athlon II X2 250, but with one of the two CPU cores disabled. As a result, the CPU has half the cache of the X2 250, with just 128KB L1 and 1MB L2 cache.

The processor runs at 2.8GHz and is rated by AMD as having a TDP of just 45W. This statistic makes the Sempron 145 look like an attractive proposition for a low-power system, such as a car PC or a small media PC, but we’d advise holding off on planning that build until you’ve seen the performance figures.

Both WPrime and Cinebench 11.5 are heavily multithreaded, and pushing them through the single core of the Sempron 145 was like blocking off three of the four lanes of a motorway – the result was similar to a 20-mile traffic jam. The processor took ages to churn through both the benchmarks, scoring a laughable 0.8 points in Cinebench 11.5 and taking 56.504 seconds to run WPrime 32M.

These spectacularly poor results were followed by three of the slowest results we’ve ever seen in our Media Benchmark suite. The Sempron’s overall score of 601 points was lower than everything else on test and highlights the false economy of buying such a cheap processor; the £60 Pentium G840 scored twice as much and was significantly faster in everyday tasks.


The Sempron 145 didn’t even compensate for its appalling performance with its power efficiency. At full load, the system drew 178W from the wall with the CPU installed. This was more than the Pentium and Core-i3 processors, despite the fact that these CPUs are more than twice as quick as the Sempron 145. The processor’s single core couldn’t provide our discrete GPU with data quick enough either, hobbling the performance of the HD 6850 1GB graphics card we used for testing.

The minimum frame rate of 14fps we saw with the Sempron 145 in our test system in Bad Company 2 at 1,920 x 1,080 was 26fps slower than the 40fps minimum we saw with the Phenom II X4 955 BE installed in the same test system. Thankfully, we could overclock the processor, pushing it all the way up to 3.9GHz using a vcore of 1.49V and a CPU/NB of 1.25V. Even at this clock speed, though, one core was still woefully inadequate.

Our time with the Sempron 145 was infuriating and demoralising. Unless you’re some kind of CPU masochist, we’d suggest buying a CPU that can keep up with today’s multithreaded applications.

Specifications

• Frequency 2.8GHz
  
• Core Sargas
  
• GPU N/A
  
• Number of cores 1 x physical
  
• Cache L1: 128KB, L2: 1MB
  
• Packaging Socket AM3+
  
• Thermal design power (TDP) 45W