AMD blows Intel into the mobile weeds
PowerNow streets ahead of SpeedStep
Lawks, as my old mum used to say. The imitators are taking over the asylum. AMD's PowerNow technology is so far ahead of Chipzilla's Geezerville/Speedstep concept as to make Intel look very second rate indeed.
Much was made of Intel's SpeedStep concept when it bounded onto the mobile stage. Indeed it was pretty cool, allowing laptops to run efficiently on batteries and to go really fast when plugged into the mains. This very story was written on a SpeedStep P3 machine supplied by Evesham Micros speeding through the Cotswolds on the Hereford Express.
But Geezerville has limitations. It rather simplistically changes core speed and voltage according to whether or not you're connected to an AC supply. PowerNow has no fewer than 32 power levels depending not on where you are, but on what you're using your laptop for.
It's down to OEMs to decide how many of these levels are available, and current machines from HP, Toshiba, Compaq, Fujitsu, NEC and Sharp typically only implement four power levels, ranging from 200MHz to 550MHz.
A rather obvious but nonetheless effective demonstration of PowerNow comes in the shape of a DVD copy of the hit (but crap) movie "Lost in Space". Using a soft DVD player, a laptop running at 500MHz will deliver a smooth performance with no dropped frames, but will tragically run out of battery power well before the subtle denouement of this sensitive movie.
Switching the processor to 200MHz will keep the batteries alive for the duration, but dropped frames make the film (even more) unwatchable.
When set to automatic, PowerNow manipulates clock speed and core voltage automatically, ensuring that the CPU only gets enough power to deliver what marketing goons would discover as a rewarding user experience - which in this case means you can see that the Robinson family survives the timewarp thingy that, when the planet explodes and thingy's dad saves his younger self, and that robot dude - erm, who cares?
So back in our Lost in Space World, when we have a dull sequence (and there's lots of those) the CPU runs at 200MHz. When the action gets hot (we wish), the CPU zaps up to 550MHz.
An AMD K6 550 mobile will set you back $99. Why go anywhere else? Duron and Athlon mobiles with PowerNow are due at the end of the year, so Intel had better wake up sharpish. ®