05-08-2011, 04:56 AM
I just tried upgrading my imac memory from (4) 2gb modules to (4) 4gb modules. The new ones are Samsung 4gb PC3-10600S DDR3-1333Mhz 204-pin SO-DIMM. iMac is 3.33 core duo.
The old ones were 2 different manufactures of memory in the Apple-supplied memory: 2gb PC3-8500 DDR3 1066Mhz....
According to the Apple support site (and a phone call to apple support) the 1333 memory should work, so that's what I bought.
When I install the cards and turn on the machine, within about 1 second I get a beep that occurs every 4-5 seconds. I let it go and it did it more than 9 times in a row. I had looked to see if this was a diagnostic signal, but it doesn't seem to match up.
I took the new memory out; reseated it to make sure it was tight; restarted - same beep.
I reinserted my old memory, and am back up and running.
Can anyone comment on this issue? I spent about 90 minutes looking around on the web and could not reach a conclusion.
Seems possible that:
a) One of the memory cards is bad
b) the 10600 / 1333 is not really compatible with the HW despite 3 sources that say it should be
c) I'm lucky smoke didn't come out of my computer
Thanks for any insight or help you can give~!