Bluetooth and battery life

[OzzieGT]

So I have a Dell Latitude D610. It has like a 4-5 hour battery life...so I am wondering, how much of an impact on this does Bluetooth have? I mean if a phone can run bluetooth with that tiny battery I would imagine that the effects on a laptop with a much higher capacity battery would be negligible. Anyone care to comment?

 

[batmanuel]

Yeah, BT was designed from the outset to be a very low-power standard so it would work on handheld devices, so it isn't going to have a huge impact on your battery life like an active WiFi connection will. The only thing that could make a difference would be if the WiFi adapter was USB 2.0 and causes your laptop to not be able to enter its low power states because of the infamous Win XP USB 2.0 bug.

As MS themselves describe it: "Windows XP SP2 installs a USB 2.0 driver that initializes any connected USB device. However, the USB 2.0 driver leaves the asynchronous scheduler component continuously running. This problem causes continuous instances of memory access that prevent the computer from entering the deeper Advanced Configuration and Power Interface (ACPI) processor idle sleep states. These processor idle sleep states are also known as C states. For example, these include the C3 and C4 states. These sleep states are designed, in part, to save battery power. If an otherwise idle portable computer cannot enter or maintain the processor idle sleep states, the computer uses its battery power more quickly than you expect."

There was supposed to be a fix coming from MS, but I'm not sure of the status of that update, since I don't currently have a lappy and haven't kept up with the discussion. I'm not sure if the BT that is integrated into most laptops is USB 2 or not, either.