EFP;227505 Wrote: > False. There are no powersave or overdrive modes for the CPU - it's not > a portable device. Unused cycles are not going to make the Squeezebox > consume less juice, they just don't do any useful work. I think the > term is idle. The box is working no less hard when playing WAV instead > of FLAC.
I hate to add fuel to this ridiculous fire, but you're actually incorrect on this point. In many microcontroller systems, the CPU does spin in a loop when there is nothing to do, possibly polling pins or just "actively doing nothing" while it waits for an interrupt. You're correct that the power usage during this kind of spinning is no different from doing useful work. However, this is not what Squeezebox does. Although the Squeezebox CPU has no true power management features like a laptop or PDA might have, it does in fact use slightly less power when idle, because it is event driven at the hardware level. It is running eight hardware threads, each of which only executes instructions when there is work to be done. When a thread has no more work to do, it issues a suspend instruction which halts it until it is sent an interrupt from another thread telling it to resume. Since CMOS logic uses very little power when static, there is some reduction in amperage. Also the PHY and SDRAM are going to use more power simply due to more data going between them. However, the notion that CPU usage materially impacts the audio circuits one way or another is not supported by any controlled listening test or measurements - both of which have been done. I give zero credit to someone who latches on to some abstruse phenomenon like this, but refuses to actually put their theory to the test. -- seanadams ------------------------------------------------------------------------ seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=38258 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
