The big issue here is whether or not the CPU has at least the SSE2 instruction set. Yours does, along with SSE3 and SSE4a. So you should be fine.
Now, whether or not that CPU will be sufficient to handle your material is another matter.
Im running CS3 atm. And I have no problem editing HDV. But the lack of AVCHD support in CS3 is why I need to upgrade.
Look at the PPBM5 benchmark results http://ppbm5.com and notice the results of the AMD Phenom 9600 results. Around 15 times slower than a fast system. It will work, but slowly because of the lack of SSE 4.1+ instructions.
The other problem is the CPU you have will slow the GPU work down because the GPU will be waiting on the CPU allot to send the data down. If you look at a newer video card for that system I would stay in the 450GPU range. That system will handle a layer of AVCHD. Much more though will likely be pushing it.