Today I got the Phenom 2 940 and said I should try it first on my M2A-VM mobo instead of buying a 790GX mobo just for a new upgrade "am2" cpu.
Phenom2 works fine on this board although it is not officially supported and it showed as "unknown processor" in the bios.
In the beginning I saw some awful benchmarks compared to various reviews I found online. Thankfully I fixed those. There were 2 reasons the performance was pretty bad compared to the reviews:
First the mighty Cool n' Quiet. With that enabled, single threaded benchmarks were around 40% slower than the reviews. I know that Phenom1 had that bug and Phenom2 has fixed it, but it apparently needs official support with BIOS or something. Anyway CnQ = Disabled.
The second reason was more sneaky. In Wprime and various Sandra tests I had around 20% lower scores. I though that was my slow memory (I have 4x2GB 800mhz kingston value with 5-5-5-18) but it wasn't. A new option appeared in the bios with this CPU (X2 6000+ didn't had it) named "Unganged Mode". It was in unganged mode by default and once I switched to Ganged all the scores were almost the same with the reviews. For a strange reason I had better results than the reviews on memory bandwidth benchs even though I have pretty low end ram modules.
Anyway in some benchmarks slightly lower and in some slightly higher than the high end hardware reviews. Pretty good results if you ask me.
Now with overclocking, I wasn't expecting much from this board. I managed to boot into Vista x64 with 3.6Ghz and 1.5v, but once I started a benchmark I BSODed after a while. Apparently my motherboard couldn't keep the voltage stable at 1.5v. Before BSODing I could see the voltage drop to 1.4. Finally I settled with 3.2ghz and 0.05 CPU Volt increase just for safety. I tested the power consumption and it seems the same with the X2 6000+ @ 3.3ghz that I had before upgrading. I was running that for a year so I feel pretty safe with the 3.2Ghz on the P2 for everyday use.
So for anyone that has some old AM2 motherboard that at least supports X2 6000+ 125w, and hopefully has that "ganged mode" option, phenom 2 is a great upgrade. I wouldn't recommend the black 940 for use on those motherboards though as you can't get so great overclocks. I think a p2 920 will easily reach 3.2ghz without multiplier and from my experience this was the max stable oc on my budget board.
Phenom2 works fine on this board although it is not officially supported and it showed as "unknown processor" in the bios.
In the beginning I saw some awful benchmarks compared to various reviews I found online. Thankfully I fixed those. There were 2 reasons the performance was pretty bad compared to the reviews:
First the mighty Cool n' Quiet. With that enabled, single threaded benchmarks were around 40% slower than the reviews. I know that Phenom1 had that bug and Phenom2 has fixed it, but it apparently needs official support with BIOS or something. Anyway CnQ = Disabled.
The second reason was more sneaky. In Wprime and various Sandra tests I had around 20% lower scores. I though that was my slow memory (I have 4x2GB 800mhz kingston value with 5-5-5-18) but it wasn't. A new option appeared in the bios with this CPU (X2 6000+ didn't had it) named "Unganged Mode". It was in unganged mode by default and once I switched to Ganged all the scores were almost the same with the reviews. For a strange reason I had better results than the reviews on memory bandwidth benchs even though I have pretty low end ram modules.
Anyway in some benchmarks slightly lower and in some slightly higher than the high end hardware reviews. Pretty good results if you ask me.
Now with overclocking, I wasn't expecting much from this board. I managed to boot into Vista x64 with 3.6Ghz and 1.5v, but once I started a benchmark I BSODed after a while. Apparently my motherboard couldn't keep the voltage stable at 1.5v. Before BSODing I could see the voltage drop to 1.4. Finally I settled with 3.2ghz and 0.05 CPU Volt increase just for safety. I tested the power consumption and it seems the same with the X2 6000+ @ 3.3ghz that I had before upgrading. I was running that for a year so I feel pretty safe with the 3.2Ghz on the P2 for everyday use.
So for anyone that has some old AM2 motherboard that at least supports X2 6000+ 125w, and hopefully has that "ganged mode" option, phenom 2 is a great upgrade. I wouldn't recommend the black 940 for use on those motherboards though as you can't get so great overclocks. I think a p2 920 will easily reach 3.2ghz without multiplier and from my experience this was the max stable oc on my budget board.