If you are looking to upgrade an AMD processor on a budget or build your own computer, then the AMD Athlon II 630 Propus is a very solid option that offers a good price / performance ratio. It is one of the few quad core processors under one hundred dollars. It operates at 2.8 GHz and uses an AM3 socket type.
Based on a variety of reviews from different websites selling the processor, it scores very highly on the Windows 7 performance rating simply when running at stock speed. If overclocked this score can be increased. Additionally, it is a quiet and efficient processor that runs relatively cool at stock speeds.
As an Athlon it lacks an L3 cache which may be a factor depending upon your build, but the performance difference between the quad core with an L3 cache and without has been shown to be around 7%. With the difference between the two levels of performance relatively close, the Athlon II x4 630 Propus is a very good choice for the money. If you need that extra performance then it might be important to pay the extra money.
The 2.8GHz speed is not as fast as more expensive dual or tri core processors, but with four cores it runs multi-threaded applications far better. This allows for strong video editing and encoding, which are often multi-threaded applications. If you are looking to upgrade an older single or dual core processor that has been handling your video editing then this is a great core upgrade at a very reasonable price.
In conclusion, this is a great quad core processor for just one hundred dollars that can work as a good upgrade or a starting point in a new build.