For sometime now my MacBook has been running noisy and hot. It is annoying and I think it is probably also the reason I’ve had some unplanned shutdowns recently. Unfortunately OS X doesn’t provide much in the way of built in tools to put numbers on the temperature and so I did some research last night and tracked down Tunabelly software’s TG Pro (Temperature Graph?), which I installed this morning.
Seeing the CPU core temperatures not far shy of 100°C and the fan speed near the top of its range, over 5,000 RPM, was what I’d feared. However, it also popped up a prompt to look for what was consuming CPU time and I spotted nessusd somehow grabbing over 300%. No, I didn’t understand that either but I did recognise the name as almost certainly being related to Nessus, a piece of software from Tenable Network Security. I had installed it as part of the Open University M811 Information Security course that I recently completed. I hadn’t been overly impressed with the results, which seemed quite a scattergun approach, coloured in nicely but potentially hiding important issues under too much information, but I hadn’t uninstalled it even though I hadn’t run another scan. I have colleagues who are using it for network wide scans and very happy with the results but actively using it from a server is a different scenario from having it needlessly grinding away in the background on a client machine.
Nothing was to be lost by removing Nessus although it took some digging around to figure out just how to do that as it installs a System Preferences icon rather than acting as a regular program. However, a little browsing round the Tenable site did lead me to the relevant documentation. As soon as I stopped the service, the fan noise started dropping along with the temperature. Removing the software entirely was easy although I say that as an experienced geek. You are poking around in the beating heart of the Operating System so proceed with care and make sure you only remove the files and directories suggested – their neighbours keep your computer alive.
I think I’m going to buy TG Pro. I’ve got all this from the free trial but, not only am I a sucker for information about what is happening inside the machine, I think the blissful silence I am enjoying (and the expected benefit for the life and health of my primary computer) are worth it.