|As of right now AM3 processors are able to utilize both DDR3 and DDR2 ram because both DDR3 and DDR2 are integrated into the AM3 processors memory controller. So yes current AM3 processors will work with DDR2 ram.|
It terms of ram performance using DDR2 vs. DDR3 on the current AM3 processors, there isn't much diff at all. In the future when AM3 processors start to utilize higher DDR3 speeds of 1600mhz or higher, then you will start to notice a real performance increase over DDR2 1066mhz or DRR2 800mhz even, but as of now you won't considering current AM3 processors can't ultilize anything over DDR3 1333mhz speeds and the diff in performance between DDR3 1333mhz and that off DDR2 1066mhz or even DDR2 800mhz for the matter is minimal overall as you can see here for example......
The current AM3 processor (the Denab core Phenom II based architecture) was initially designed around the AM2+ platform. The only diff between the current AM3 processor and AM2+ processors, is that AM3 processors has an additional DDR3 memory controller to go along with the traditional DDR2 memory controller. Where AM2+ processors just have a DDR2 memory controller only.
AMD could have stuck with the AM2+ platform and just added DDR3 memory support for it considering there is no diff between an AM2+ platform and an AM3 platform, but to avoid marketing confusion they decided to make an AM3 platform with DDR3 memory support to keep it separate from the AM2+ platform that traditonally uses DDR2 memory. That's the only real diff between an AM2+ platform and an AM3 platform.
Now, if you're currently using an AM2 platform then you are most likely going to be out of luck putting an AM3 processor in it. AM2 platforms may theoretically be backwards compatible with AM3 processors, but the architecture that supports the AM2 platform is diff then the ones that Support the AM3 and AM2+ platforms. So even if you were lucky enough to get an AM3 processor to be able to work with a AM2 platform, it would take a big hit in performance, because the Hyper Transport technology on the AM2 platforms only supports Hyper Transport 2.0 instead of Hyper Transport 3.0 found on the AM3 and AM2+ platforms in which both AM3 and AM2+ processors are equipped with. Even using an AM2+ processor on an AM2 platform will take a big hit in performance let alone using an AM3 processor. due to the lack of Hyper Transport 3.0.
Hope this answers your question.
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