PureOverclock has published a review of the AMD Athlon II X4 640 CPU

With six new Athlon II chips, AMD is keeping relentless in their attack on mid to lower end Intel lineup. For review, we've got the Athlon II X4 640. By specs, it's awfully familiar. It's essentially an Athlon II X4 635, just clocked up 100MHz. As you'll soon see during our overclocking sessions, these Athlon II chips have some serious overhead potential, so let's dive right in and get this chip juiced up.

AMD Athlon II X4 640 Review