[Solved] Will a AM3 CPU in a AM2+ socket and DDR2 Memory slow my computer down?

I currently have a Athlon 64 x2 5200+(2.7Ghz) CPU in a AM2+ socket with 4GB or DDR2 667 RAM. If I upgraded my CPU to a Phenom II X4 2.8Ghz CPU, would my computer slow down, speed up, or stay the same?

Other Info:
I am asking this because I hear that using a AM3 CPU in a AM2+ socket with DDR2 RAM will bottleneck the RAM, but what I cant find is that the bottle-necking of the RAM lower the computers performance lower than it originally was. I plan on buying the Phenom II X4 soon, unless its a bad idea.
My motherboard Supports AM3 socket CPU's
I cannot upgrade anything else but the CPU.(Limited Money)
I have a aftermarket Heat-sink that will keep almost any CPU I get cool.

If you need the exact names or specs for any of my components, please ask.

you'd get a huge performance boost.

I got two opposite answers... not sure what to do yet...

clarification: the processor you have now is junk. Upgrading will give a huge boost in performance. make sure the BIOS supports it before you install new processor. ( update BIOS while old processor is in the board if needed ).

you will never see the true performance of that cpu because the ht link speed is less than half what it would be on an am3+ board. also the ram is slllloooooow... upgrading to a new cheap am3+ board and ram with 1066 or even 1333 will show a huge boost in performance. well at least 50% over just banging it into your current board.

oh i almost forgot not all am2 boards will support am3 cpu's as the manufacturers of the boards tend not to upgrade there bios's when new arcitecture comes out even if its on a similar socket that would generally work. i had this issue with both asus and gigabyte when i had my old amd 6000x2 and wanted to upgrade to phenom. so make sure it is fully supported b4 you buy or you will have to upgrade the mobo, which i suggest you do as soon as you can.

cool, hope you find work soon m8...