I’m : a programmer, writer, podcaster, geek, and coffee enthusiast.

iStat Menus was recently updated for Snow Leopard. I always have this app running — I’m a very impatient computer user, and when something’s slow, I want to know exactly why. This helps me figure out what component or condition is to blame so I can make better decisions for future component upgrades and computer purchases.

This is my 2008 Mac Pro encoding a DVD with Handbrake, maxing out all eight cores while occasionally touching the disks. This task is obviously CPU-bound, but I don’t do it frequently enough to need a CPU upgrade — in fact, CPU power is the last limit I’m likely to hit with this computer. But if I’m doing something frequently that’s really slamming the disks, that’s worth knowing so I can plan a disk upgrade.

The new version of iStat Menus has a power-consumption monitor (far left) as reported by the power supply. (I didn’t even know that the Mac Pro’s power supply could report on its own consumption.) While I don’t intend to keep the power-consumption display enabled for very long, I’m running it for a few days to get a general idea of how much power I’m using. (Why, you ask? Well, why not?)

The “idle” consumption (web browsing, other easy tasks) with four disks is about 140 W, while it pushes 270 W at full CPU load. iStat breaks it down further in that item’s pulldown menu: at full load, my CPUs are using 47 and 43 W, respectively, with the northbridge using 23 W (which sounds high — do dual-Harpertown northbridges really use that much power?) and the RAM banks using 14 and 16 W, respectively.

At sustained full load, the Mac Pro’s four 120mm fans kept the CPUs at a healthy 50ºC, only 28º above ambient, spinning at 600-800 RPM. For whatever it’s worth, I’ve never had my Mac Pro spin its fans up to an audible level, even at full load. This, alone, is an impressive feat of engineering.

My computer is really a fantastic machine, and like a high-performance car’s engine noise and tachometer, iStat Menus keeps me updated about what’s going on under the hood.