#FF00AA

Karagounis [the group program manager of Microsoft’s Performance team] points out that “minimizing memory usage on low-power platforms can prolong battery life,” noting that “In any PC, RAM is constantly consuming power. If an OS uses a lot of memory, it can force device manufacturers to include more physical RAM. The more RAM you have on board, the more power it uses, the less battery life you get.

“Having additional RAM on a tablet device can, in some instances, shave days off the amount of time the tablet can sit on your coffee table looking off but staying fresh and up to date,” Karagounis wrote.

I always assumed it had to be negligible.

Actually, in operation, it probably be is — but the writeup specifically mentions battery usage when the tablet is sleeping, and that makes sense: RAM is just about the one and only thing that can’t be turned off at all while the device is idle.

When you see that the iPhone 4S loses one third of its standby battery life and the only reason I can imagine is Siri’s requirement for the gyroscope and accelerometer to stay on at all times (so that it activates when you put the phone to your ear), it makes sense that doubling the number of RAM transistors to power would have a noticeable effect after all.