Looking back at the performance graphs, Athlon II X4 645 performed as expected in every way, both good and bad, and even throwing a few pleasant surprises along the way. Strong points for this processor are by far its reasonable price, and fast four physical CPU cores that in some cases perform almost unenviable good. For example in rendering benchmarks, where Athlon II X4 645 manages to match and even exceed the performance of Phenom II X4 945, without breaking a sweat. In its new C3 revision, Athlon II is seeing a nice drop in power consumption, in this case up to 20 W under load compared to the C2 revision of Athlon II X4 630, and that's not something you can ignore. With new optimizations Athlon II X4 645 reaches the same level as Intel's older Core 2 Quad models regarding power efficiency, but is still miles away from new Core i3 models. Luckily it has no problems matching their performance levels, except in single-threaded applications, so higher power consumption can be overlooked a bit. A Weak point for this processor, as well as the whole Athlon II X4 familiy is its unstable performance. Depending on the application, performance can vary from stellar to downright poor. This is without doubt caused by the lack of large L3 cache memory and inability to queue instructions, making the cores communicate with the much much slower system DRAM memory to get information on what to process next. Luckily, in the general computing world, where general purpose users dominate the population, and professional applications are very rare, this may not be such a handicap after all.

With a price of $ 122, fast clocked cores, strictly okay power consumption and backward compatibility to AM2+ sockets using DDR2 or DDR3 memory, it's really hard to find flaws in Athlon II X4 645. Even in its weakest segment, gaming performance, Athlon II X4 645 performed more than acceptable making up the lack of L3 cache with higher clocked cores. But I can't shake the feeling that AMD almost forced this fastest Athlon II X4 model to where it landed, and with just a little bit of luck, or should we say help from Intel. Although Intel can come up with an answer to Athlon II X4 645 quite easily, it chooses not to play AMD's aggressive pricing game and in doing so, it's making more than enough room on the market that AMD can exploit with processors such is Athlon II X4 645.