[M. Bison]

Thanks for the Answer Bison.
Im refering to the 2nd graph actually of the popular maps 2 server notice how the blue line is at its highest point (48/48 the server max) right before the Oct 28th 12:00 Am mark(in bold)
and how the yellow fps line drops well below the blue line at exact moment, and as the server decreases to roughly 40 people by 12:00 Am how the fps line goes back up.
Actually yes most of the people have noticed the server lag really hard on Port, which is the only even occasionally played of the two maps.

If you check the other graph, you'll notice that the fps drop occurred on cs_assault. People don't like that map, so quite a few typically rage quit during and after it. GameMe doesn't update the population count right away, so it may show the population drop as occurring on the map directly after it.

The 2nd image shows that fps and population count aren't particularly related on Popular Maps. The fps may drop slightly (which doesn't matter), but the overall big drops occur on select maps (assault, port, cpl_strike). This observation doesn't apply to the 24/7 servers which do have a CPU bottleneck.