Rendering is very slow!!!

Agree with Rick. That seems to be yet another case of wrong expectations and a wrong understanding about how AE works and what it is meant for. Of course there may be potential to optimize your render process in some way, but without even a shred of real info about your project and its contents, actual render settings and your system nobody can gauge that. The long and short of it is that you will need to get used to it. Simple math can tell us that for two hours of rendering and an eight minute clip at presumed 60 FPS only takes a fraction of a second per frame, which is actually quite good already. So even if you optimize this further, chances are it's never going to be under 1.5 hours.

Mylenium

Rendering time depends on the composition frame size, frame rate, source files, effects, and your system resources. Many of my compositions render at the rate of several frames per second, but I do a lot of visual effects compositions that can take several minutes a frame to render. 

You are trying to render an 8 minute video and that tells me that you are using After Effects as a video editing app. It is not desgned to edit video, it's a terrible video editing tool, and, for the most part your comps should not be longer than a single shot. On rare occasions where you need to make a transition between two shots that you cannot create in an NLE like Premiere Pro, you have to put more than one shot in a comp. If you are doing lyric videos (dynamic text animations) or explainer videos, it is a good idea to limit the comp length to one sentence or phrase. NLE's like Premiere Pro, treat video completely differently. After Effects looks at every pixel on every frame on every layer when it renders so the renders always take longer than they do in Premiere Pro. 

Taking all that into consideration, and not having any real idea about your workflow or system resources, two hours to render an eight-minute video may be very reasonable. I rendered a comp yesterday that was 80 frames and it took nearly 20 minutes using a background rendering system that cuts the standard render time by about 70% and I was happy because the comp had more than 100 layers and about 20 particle effects.