When your CPU is not crunching data, it goes into an idle cycle. This cycle cools the processor down to some degree but it still generates heat and draws power. A CPU cooler executes an "HLT" command that puts the processor in a suspend mode. The result is a cooler CPU which can extend the life of the processor, lessen power usage (albeit by a tiny amount), and on laptops, extend battery life (reportedly by as much as a half hour).

The latest CPU cooler in geekdom is Leading WinTech's Waterfall Pro 1.2 (WFP). WFP gives your processor the ol' HLT (and can allegedly decrease your idle processor's temp by up to 30c), but it adds a number of other interesting features.

The first new addition is called "CPU Throttling" and might be useful to overclockers, computer hobbyists who enjoy pushing the limits of their computer's CPU by cranking up the clock speed of the processor (e.g. tweaking a K6-2 300 MHz processor so that it runs at 350 MHz). The risk in overclocking is frying your processor, so overclockers take great pains to add more ventilation to their cases, add bigger heat sinks, extra cooling fans, thermometers, etc. The cooling that a CPU cooler delivers is not of much help when overclocking (it only kicks in when your system is idle, after all), but Waterfall Pro's CPU Throttling might be.

Simply explained, CPU Throttling allows you to set a maximum value for your CPU's performance. By setting your overclocked processor at, say 80% instead of its 100% potential, you can prevent it from overheating when faced with a particularly processor-intensive task. By running a benchmark program and tweaking the throttle value in Waterfall Pro, you're able to come up with a maximum CPU load that gives you the best performance for your overclocked processor. [Editor's Note: No one at Street Tech has tried this feature of WFP (none of us are overclockers), so we don't know if, or how well, CPU Throttling works. If you've tried it, let us know how it went.]

Waterfall Pro also includes software that can monitor thermometers and sensors that are built into some motherboards. If your motherboard has this feature but isn't supported by Waterfall Pro yet, the makers plan on releasing new downloadable sensor plug-ins for more boards as they're authored. A set of alarms are available that can be activated to alert you to a voltage increase or drop in a cooling fan, a CPU overheat, chipset temp., etc. Each alarm can be assigned to a WAV file on your system ("Burn, baby, burn, disco inferno...").

This latest release of Waterfall includes some file system and virtual memory optimization features as well. The file system optimization treats your PC like a server rather than a desktop machine. In desktop mode, your Virtual File Allocation Table (VFAT) allocates only 10K of memory for tracking down recently-accessed files and folders. In server mode, 40K is assigned. This is no great innovation (you can do this yourself by going to the Performance tab of your System Control Panel), but WFP does it automatically. The virtual memory (VM) optimization can also be done manually but is built into WFP. It sets the min. and max. VM settings based on the amount of RAM in your system and places the VM swap file on the fastest drive available on your machine.

Unless you're the kind of chip head who likes to obsessively tweak your PC for optimal performance, or an overclocker looking for a safety net on your hotwired CPU, most of Waterfall Pro's features won't be of much use. But this little app (and by little we mean *really* little, 90Kb little) is worth it just for its power-saving and CPU cooling features. I'm definitely planning on installing it on my laptop and seeing how it improves battery performance.

There are two versions of Waterfall Pro. The freeware version has an ad for Leading WinTech (and its sponsors) that displays for ten seconds whenever you launch WFP. The $15 shareware version is ad-free.

- Gareth Branwyn [10/8/98]