I currently have a Gigabyte GA-M57SLI-S4 motherboard with an Athlon 64 X2 4200+ (don't remember if it's Windsor or Brisbane core, but it's 2.2Ghz). From Gigabyte's website:
(Note) If you install an AMD AM3/AM2+ CPU on AM2 motherboard, the system bus speed will downgrade from HT3.0(5200 MT/s) to HT1.0 (2000 MT/s); however, the frequency of AM2+ CPU will not be impacted.
From what I've read around in different forums, the HT speed doesn't impact performance as much as raw CPU power. So my question is...
1) Will an AM3 cpu be impacted by being placed in this motherboard?
2) If 'No' to question 1, would I be well of just upgrading cpu to Phenom II x2 555 (3.2Ghz). I realize I couldn't take advantage of DDR3 memory, but upgrading memory would also require upgrading motherboard.
3) If 'Yes' to question 1, would one of the Phenom CPUs (not Phenom II) still be a worthwhile upgrade? Or should I really consider upgrading motherboard and memory to get an AM3 CPU at this point?
1. not much, but ddr3 is faster. I would sell your old ddr2, motherboard, and 4200 as a package deal on craigslist or anandtech's for sale forum, and make the switch to ddr3 and a newer chipset, such as the 870 or 890. If you don't get any offers as a package, you may have to part them out.
2. The 870 boards are only about $25 more for biostar or some msi models. They start at around $90, but some may be on sale black friday weekend if you live in the usa.
I would go for a target price of around $80 for the cpu even if you have to buy used. I found a 920 used for $150 recently, and talked the seller down to $100. Lots of folks out of work or need cash now.
3. Some phenom II's are less than $100 on sale as oem at places like newegg. Open box cpus are a bad deal; priced about the same due to shipping charges. Buy used on one of the forums, but do your homework first, and offer less. You might get lucky. Start by selling the ddr2 first, then find an affordable cpu, and save the board and ddr3 for last. Stick to one of the following brands of ram: corsair, crucial, kingston, or samsung (hynix). Other brands may give you more problems.