By "laptop memory" you mean SO-DIMMs; the only significant difference to full-size DIMMs is, well, size. Voltage and frequency tends to be the same, leaving asi

By "laptop memory" you mean SO-DIMMs; the only significant difference to full-size DIMMs is, well, size. Voltage and frequency tends to be the same, leaving aside extreme overclocker's RAM. In c't magazine's review of the current iMac, they found that the whole machine appears to have a power limit which is shared by CPU and GPU, so yeah, Apple are definitely doing something fancy in that regard.