I'm just curious, does the 10.5.7 release solved the issue that uMBP 470 can't support 8G RAM?
sorry for the confusing, but MB470 and MB471 and even 17 inch MBPs are using the same chipset, so I guess it was just SW/Firmware limitation
Software limitation imposed by Apple. The hardware can support 8 GB, Apple just doesn't want to add that support, only for the 17" model.
but the 2.66 and the 2.93 GHz can hold up to 8 gigs. Something smells fishy.
Apple screwed up, it happens.
what i think happened is instead of creating different boards for the high end 15" and 17" they just the same one for both. but the 2.4Ghz is still the old chipset hence half the 3MB instead of 6MB. this is probably why it doesnt support the 8GB of RAM.
It has nothing to do with the amount of L2 Cache in the processor. All Intel C2D P8X00 series processors can use up to 8GB of RAM provided the chipset allows it. Not sure what Apple has done to block that, but if you were to pair the P8600 with a PM45 chipset, it would support 8GB (maybe even 16GB) of DDR2/DDR3.