Eh...kind of a weak topic, and i don't really understand how you're writing a graduate-level "graduation paper" (?) that only requires a couple of paragrahs...
FYI, i have a masters in elec. & Comp. Eng. never had to write a paper that was only a couple of paragraphs.
that said, if you're a little more specific, your focus can be more closely defined, instad of "how does CPU overclocknig affect games", maybe somethign like "the effect of CPU overclocking versus graphics engine speed on increasing performance of popular video games"
take two specific data points, and compare and contrast how the speed of the CPU affects the performance versus the speed of the graphics engine (video card). contrast high resolution, detail levels, shading, fog, etc... (stuff that is done by a high end video card, making it the bottleneck in the system - the CPu has no trouble keeping up the level of vertices and AI as fast as the video card can take them in) versus ultra low res, low detail, eveythign off, where the CPU is the bottleneck (i.e., the video card is an open well that the CPU can just throw verticies at as quickly as posisble.) also turn up the AI in the game as much as possible - make the CPU work, not the graphics engine.
then you get data points, and see how each component affects overall performance as you speed them up or slow them down (get at least three speed data points and graph them).
take the data and come up with some extrapolation, find a poitn where the crossover occurs (is it resolution or detail level?) you should find a point where increasing the CPU speed no longer gets you linear performance gain. or, on the converse, whee increasing graphics performance no longer buys you anythign since the lower-perf setting can keep up no problem anyway.
then look at possibly adjusting the link between the two engines, PCIe 1x vs 16x - you'll probably see that there is very little difference above 4x or so - the CPU still can't max out the bandwidth with enough verticies...the only thing that affects it is the surface loading at the start of the game - as the card pulls out the textures and initail code from memory - but since that takes an insignificnt amount of time relative to the whole game, it doesn't do much. (i.e., sorry folks, but PCIe doesn't actually buy you anythiign over AGP4x)
if you want to go further, look at memory size and speeds, memory latencies/timings, FSB speeds, cache on/off, or gfx memory sizes. but for a few paragraphs, that's a little much i think.
good luck.