RAM in late 09 and 2010 backwards compatible?

[pt0016]

Can I use 1066MHz ram in the new 2010 iMacs, specified for 1333MHz? Are they backwards compatible?

Cheers.

 

[Hellhammer]

You can but then the 1333MHz modules will underclock themselves to 1066MHz. I doubt you would notice any difference though

 

[pt0016]

You can but then the 1333MHz modules will underclock themselves to 1066MHz. I doubt you would notice any difference though

Hmm, well in that case, I have 2x 1gb of 1066MHz DDR3 ram, from my other iMac I had.

Would it be smart to upgrade to 6gb (4gb standard + 2gb) and underclock it to 1066MHz, or would it be better to have only 4gb of 1333MHz?

Cheers

 

[Hellhammer]

Hmm, well in that case, I have 2x 1gb of 1066MHz DDR3 ram, from my other iMac I had.

Would it be smart to upgrade to 6gb (4gb standard + 2gb) and underclock it to 1066MHz, or would it be better to have only 4gb of 1333MHz?

Cheers

If you need more RAM, yes. The clock speed just increases the maximum bandwidth but 1066MHz is already pretty fast, most apps cannot take advantage of the extra speed. I would put it there