[Langdon]

can the Clamshell iBooks use PC66 SODIMMs?
The spec sheet from Apple recommends PC100 but the BUS speed of all of the iBooks is 66Mhz. So even if I use PC100 its clocked down to the top end of the BUS speed. So no speed loss would happen when PC66 is used right?

[tooki]

All the clamshell iBooks (and one early dual-USB iBook, too) use PC66 SDRAM SO-DIMMs. I don't know what Apple spec sheet you're looking at that specifies PC100 for all iBooks, cuz it's not true!

tooki

[pat++]

Apple says PC100 for iBooks, but PC66 *should* work too on early models with 66mhz system bus. The point is that PC100 might be cheaper because it's easier to find...

[RadarBob2]

i dunno what kind my precious uses, I just went to www.4allmemory.com and that site told me what was compatable based on my model. that's what i bought.

[ghporter]

PC100 RAM should work just fine in a machine that uses PC66. The opposite is not the case, since a machine that needs faster RAM will not slow down to accomodate slower RAM.

[Langdon]

Yes, Apple recommends PC100. The PDF you get from the Apple support site says it.

The reason that I have come to believe is that the onboard memory is PC100. When you add a PC66 chip into the open slot the System profiler shows the PC66 specs but not the details of the RAM on the motherboard.

When you put in PC100 SODIMM into the open slot the Profiler reads all the RAM at PC100. I asked because I had 4 SODIMMs sitting around and someone with a Bluebery iBook asked if they could have one but I wanted to be sure that Apple's recommendation was not a requirement. I was not in themarket to buy, but thanks.
And PC66 will work in computers that are meant to have PC100, I tested it on a Sawtooth. The computer just clocks down the all the RAM to 66Mhz. It is not smart since it slows down your system but it does work.