My application is using MS Charts, which shows very fast data And when I open multiple windows my CPU is always < 25%. I have 4 cores, so drawing in ms chart is performed only on 1 core. How can I make it to use all cores
You can't. Like any UI component, Chart can only perform drawing on a single thread. Your program's main UI thread to be specific. This is not normally a problem, the amount of pixels that a modern cpu core can whip to the screen greatly outpaces the human's eye ability to perceive them. You do not want to keep it so busy that one core is burning 100% load for the main thread, that's going to be perceptible by the user when the UI thread starts responding sluggishly to mouse and keyboard input. Fine-tuning this is certainly a programmer's job.