Web Informant #315, 5 February 2003: Dell's Gigahertz Dupe




If you have to buy a laptop these days, don't buy a Dell SmartStep. There is nothing smart about it, and indeed Dell tells me they are going to discontinue the line shortly. But getting to the bottom of this isn't easy, and bear with me while I explain.


I am finding out that buying a computer these days is a lot like buying a car. There are too many things to worry about, and the sales help is downright wrong on basic facts. As a case in point, I helped a friend of mine last night get a new PC at the local Gateway retail store. I am glad I went along, because the sales person was insistent that the 32X CD drive was faster than the 48X drive my friend was considering. The sales person was surprised when I claimed otherwise. I almost asked if they had any matching floor mats with a Gateway logo, but held my tongue.


Anyway, back to the Dell SmartStep. Dell makes pretty good products as a rule, but this one is a dog. And the reason is that if you want a 2 GHz laptop, you only get that speed when the laptop is hooked up to AC power. When it is unplugged, it is running at half that speed. Omid Rahmat of Tom's Hardware calls it Dell's Gigahertz Dupe, and I am inclined to agree with him.


Laptops have very tight power budgets, and the biggest power consumer is typically the processor (along with the screen and hard disk drive). In principle, there are two ways to cut down on a processor's energy consumption: reduce its operating voltage, or slow down its clock speed. Cutting voltage is a better method, according to Rahmat: this is because the processor's energy consumption is proportional to the square of the voltage, while linear to the clock speed. So anything that a manufacturer can do to cut down on power is usually a good thing, since people who buy laptops have this expectation that they can carry them around unplugged for a few hours and get some useful work done. But Dell blew it this time around.


The problem has to do with the choice of the processor in the SmartStep, an Intel Pentium 4 that is usually seen in many desktops. Most laptops use mobile versions of the venerable Pentium: the reason is these versions consume less power, operate longer on batteries and generate less heat than their desktop cousins. Dell decided to use the desktop version to save some money (the desktop version costs $350 less than the mobile version), money that can translate into better margins for Dell.


Windows laptops have two ways of saving juice: one is in hardware, called SpeedStep; and one is in the operating system software, called Advanced Power and Configuration Interface. Both methods trade off on voltage and clock speed. Unfortunately, the desktop P4 doesn't recognize SpeedStep, and thus has to throttle down to half-speed using APCI to save on energy. This is outside the user control, so when you unplug the laptop, you bring it to half its rated clock speed. That stinks.


When I called Dell about this, they agreed that wasn't the best of situations, and mentioned that they are planning on discontinuing the SmartStep line of laptops in the next month, and replacing it with something from their Inspiron line that won't throttle down to half speed. That's good, although you still will lose some clock speed and performance when you unplug these newer laptops. In the meantime, if you are in the market for a new laptop, perhaps you should look carefully at what processor is running inside it and stick with the more expensive mobile Pentium versions. Or buy something that you are planning on keeping near an AC power outlet.