Movsb can move the data in one instruction so I don't see why it's 'unrealistic' I don't really get your objection. 512bytes is rather arbitrary, yes. But I do

Movsb can move the data in one instruction so I don't see why it's 'unrealistic' I don't really get your objection. 512bytes is rather arbitrary, yes. But I don't see why it becomes less relevant when it's ram.