Can someone confirm the way the cursor moves is different when i swtiched 1920 resolution to 1600 resolution in windows for a game like warcraft 3 frozen throne. it really does feel different, tho it could be in my mind. I kept the resolution in game the same
This can depend on the game/engine, I think WC3 FT (purely from memory) might suffer from this. The "space" by which your mouse is traveling over is mathematically bigger as you turn up the resolution, where as the real space on your monitor it occupies is typically stretched/fitted, this means you'll essentially have a sensitivity change in your mouse as you change the size of the screen resolution. it'll take more movement to get from one side of the screen to the other with a higher res.
That doesn't necessarily have to be the case with RTS games but certainly with older ones I think it pretty much always was. This doesn't effect sample speed or anything like that, it's not less accurate, just less sensitive you can change the sensitivity on your mouse to combat this.
I would add that typically new cards aren't going to effect the mouse in a negative way, better FPS and better game frame rate will only make mouse samples be accepted by the engine more readily (when frame rate and tick rate are tied together). If you're used to relatively slow frame rates the effect of seeing higher ones for the first time can at first seem unnatural or offputting, I've seen this with console gamers who play on typically 30fps or lower suddenly seeing 120fps for the first time and saying it looks/feels strange. Same thing happened when some movies were displayed in 50 or 60fps instead of the traditional 24. If that happens to be the cause then you'll get over it really fast and the reverse will seem much worse, slow frame rates will feel unbearable.