How to reduce CPU usage of a program?

Question

I wrote a multi-threaded program which does some CPU heavy computation with a lot of floating point operations. More specifically, it's a program which compares animation sequences frame by frame. I.e. it compares frame data from animation A with all the frames in animation B, for all frames in animation A. I carry out this intensive operation for different animations in parallel, so the program can be working on A-B pair, B-C pair and C-A pair in parallel. The program is using QtConcurrent and a "map" function which maps a container with motions onto a function. QtConcurrent manages thread pool for me, I am working on Intel Quad Core processor so it spawns 4 threads.

Now, the problem is that my process destroys my CPU. The usage is 100% constant and I actually get a Blue Screen of Death if I run my program on a big enough set of motions (Page fault in non-paged area). I suspect that this is because my computer is overclocked. However, could this be because of the way I coded my program? Some very intensive benchamrking tools I used to test my machine's stability never crashed my PC. Is there any way to control how my program uses my CPU to reduce the load? Or perhaps I am misunderstanding my problem?

Answer 1

Overclocking PCs can lead to all sorts of strange problems. If you suspect that to be the root cause of your problem, try to clock it in reasonable ranges and retry your tests.

It could also be some sort of quite strange memory-bug where you corrupt your RAM in a way where Windows (I guess that OS, because of BSOD) cannot recover anymore (very unlikely, but who knows).

Another possibility I can think of is, that you've got some error in your threading-implementation which kills windows.

But at first, I'd look at the overclocking-issue...