So, summer’s back and with it are the case fans on my home PC. It’s by and large a quiet machine, mostly puttering softly to itself unless being made to run a game or, peculiarly, YouTube videos (because Adobe still doesn’t know how to make a video player that doesn’t consume 100% CPU time).
But I’ve been noticing lately that just running idle, the TrediaSix has been very loud, fans busily churning air through its aluminum corridors. And this happens all the time. Some quick inspection with Process Explorer determined that it was a process called MsMpEng.exe just jammin’ on both CPU time and I/O. It was running every time the screensaver flicked on, sometimes preventing the machine from sleeping. MsMpEng.exe is a process integral to the free antivirus software Microsoft Security Essentials. It’s a decent enough bit of security software, with good detection rates and fairly light on the resources. So what was the deal with it seemingly scanning everything, all the time?
It’s hard to say, but I have a pretty good guess. Take a look at this dialog:
The box at the top is ticked by default, and for a decent enough reason. It’s a good idea to scan your system every so often for bugs, especially if you download a lot of stuff. It’s also a good idea to let the app manage itself so you don’t have to worry about it.
But it turns out that MSSE is a little insecure. It wasn’t enough that it was running a quick scan every stinkin’ day, it had to peek under every carpet and poke through every hedge. I have around a half a terabyte of space on this PC, which is just not a lot by modern standards, but there are still many thousands of files littering these drives, and an external drive that I use for backups. I figure that MSSE isn’t able to scan those dusty places in its “Quick Scans” and so it uses the “Run a scheduled scan on my PC” option as an excuse to also vacuum up any spare CPU time on a deeper scan… a scan that never has time to complete, because of course when my dang PC is on, I’m usually using it which halts the scan. So then the stupid thing either starts over from scratch each time, or picks up where it left off, but either way it’s just burning CPU cycles to little avail.
If it’s true that MSSE is trying deeper scans in the background, the intentions are surely good, but it’s just not useful to me, makes a racket, wears out my PC components (which are vintage 2008 and already a little creaky) and above all does me very little good when I’m already on a clean machine.
At any rate, I tried fiddling with other options on this rather limited dialog in an effort to get MsMpEng.exe to use less CPU power or maybe only engaging in this behavior once per week, but nothing seemed to work. Unticking that box up there? The one labeled “Run a scheduled scan…?” That worked immediately. I’ve been watching with SpeedFan and Process Explorer, and things have settled considerably.
My PC is quieter, and happier, and roughly about as safe. Really? Yeah, probably. You see, even if you have the scheduled scan disabled, the live scanner will still be performing in real time, scrutinizing every executable you run anyway. And, it’ll also shout out if it’s been a while since the last quick scan, whether its scheduled or not. So as long as I’m not terribly foolish or very unlucky, I’ll be fine.
It’s going to be a nice and quiet summer.