UltimateHardware.net reviewed the AMD Sempron 3400 processor. The AMD Sempron 3400 runs at 2 GHz, just like Sempron 3300+ and Athlon 64 3200+. The difference between these three CPUs is the amount of L2 memory cache. While Sempron 3400+ has 256 KB of L2 cache, Sempron 3300+ has 128 KB and Athlon 64 3200+ has 1 MB. This Sempron processor has the 64-bit instructions activated, which makes it a true Athlon 64 CPU but with less memory cache. So you can think of Sempron 3400+ as a "light version" of Athlon 64 3200+.

The Sempron 3400 was outclassed by the 2.4 Ghz Athlon64 3400 although it did offer performance close to the Athlon64 3000. When using benchmarks which require a high clock speed the Sempron 3400 performed well and actually beat the Athlon64 3000. However when using games software the 256K L2 Cache found on the Sempron 3400 gave the Athlon64 3000 the edge.