I've been facing a very annoying problem with my Lenovo Thinkpad T430. Occasionally, when I'm performing some tasks that can use a good amount of CPU time, my mouse becomes highly unresponsive. It would take several seconds for it to react whenever I'm compiling a bunch of files for example.
I realize that computers normally become less responsive when they're busy, but this is the mouse. It should be responsive 99.99% of the time even when the computer is busy, at least from past experience with computers. This occurs with the touchpad, wired mouse, and bluetooth mouse, so I'm very sure it's not the mouse's fault.
It's almost as if the operating system does not prioritize the mouse driver higher than the other processes. It also feels like there are just way too many interrupts going on or something. Perhaps the mouse is only a symptom of a much larger problem?
I've recently created a Linux virtual machine (with virtualbox) and had it use all my cores. Whenever I compile any source files (which use up all my cores at 100%) the computer becomes completely unusable and the mouse barely moves. This simply isn't the case on other machines.
This problem only happens with my T430 and I've never faced this problem on other computers. I haven't tried other thinkpads before this so I'm not sure if this is a problem with the Thinkpad (I'm guessing it is however).
EDIT: I cannot confirm for sure, but my brother, who has a Thinkpad X1 Carbon (relatively new) also says he faces the same issue, so I'm really guessing it's a thinkpad thing
EDIT2: I noticed something interesting. I run a Linux virtual machine with virtualbox on this laptop (Windows 7 host), and I was compiling some source code. When compiling the source, the CPU usage goes up to 100%. When this happens, if I was using Windows, the mouse slows down and becomes barely usable. However, if I was using the Linux virtual machine, the mouse is completely unaffected. This would mean that the mouse signals are reaching fine, but Windows (or something) is taking a while to change the cursor's position. Maybe this means that the mouse cursor is being handled by a user process, and not a driver or the kernel? And now that I remember, I used to play games on this laptop. Games take up a good amount of system resources, but I never had mouse issues while playing games. This issue seems to only affect the windows cursor and nothing more.
EDIT3: Please ignore EDIT2 :) It happened in my virtual machine as well