Really for the price of that chip you would be better off parting out your current system and doing a new build with a Conroe C2D .
The E4300 and E6300 are about the same price and at stock setting will destroy that 3.4 chip not to mention the overclocking ability.
isn't 939 new than the 478 that that chip is set to run on tho? if so, you should expect 939 to be faster. but for a quick, easy upgrade for someone useing a 478 thats one great proc.