Thought that article would give you a good idea what the chips are capable without having an unlocked multiplier and being able to put high-end voltage to the CPU. Looks to me like @3400 is quite attainable, compared to an unlocked multiplier and being able to put high voltage to the CPU that will get you above the @3.6 mark.
well they got the 2.6 x3 to 3.7, which is pretty good. and I know 720's go to around 3.8. So I'm assuming the 945 will go to around 3.8ghz also, this is talking into account a high end mobo, and good cooling.
and I think you can push a lgood amount of voltage into the locked CPU's, via the MOBO's CPU voltage contoller
I asked them about the 720, when that chart wasn't working for some reason, and they said, there is a bios update for the 750a and phenom II's and as long as it is 95w or lower it will work, I might check again or look for another BIOS update.
As for their customer service I think it's good, great warranty on graphics cards, (haven't turned me down yet, and one out of the two times it was my fault), and they always answer my questions within a reasonable amount of time.
Others claim they are very slow on the RMA process, have slow customer service and don't help.
So I've heard both sides and luckily I'm on the good one.
The problem with you going the 720 route is you may only see marginal gains over your 5000. You'll be gaining an extra core, some L3 cache, and maybe a little better OC.
If you can get a confirmation on MoBo being able to use the 945, that would be the way I personally would go. 2 more cores and AM3 means you will be able to up-date the MoBo a little farther down the road.
I recently upgraded from my Athlon X2 5600 2.9 Ghz to a Phenom II X4 945 95W. My giga-byte motherboard is good for 140W, however the price for my 945 was right. The maximum temperature for this chip is 71'C (most phenoms AMD's are rated for just a few degrees over 60). The stock heatsink which came with my processor is very small and all aluminum (much smaller yet a little heavier with different fin design than my old heatsink). So I figured, what the heck! It doesn't take much to cool this thing. So I bought a new heatsink from a Athlon 6000+. These are fairly heavy and come stock with four heat pipes, copper base, and larger footprint. I am now running a cool and rock stable 3.35 ghz at 3.325 volts (max core temps I've seen runnning prime95 are 50'C). Bottom line, I'm loving it!