They just will throttle you down due to 100% cpu usage. It's a hard set flag in their system that cpu/24hr/100% load crap.. Best setup imo is ignore the guide that says 4 x 2 cores @ 1.8gb ram ( thats where it was when I did it 1.5yr ago ) was to actually do 2 x 4 cores @ 3.8gb ram and set it to run 80% CPU max and you do not run into any issues and the $300ish will last you closer to 3 months than the 1 month you are headed down. Running it as 4 x 2 core vps's @ 80% will get you a full month , and I do not know any non VM projects that use more than a few Megabytes of ram so the 1.8gb's is enough.. Just saying , you goin burn threw it faster and the guides are there to help you maximize the $300 in Virtual CPU crunching , as its just a slice of what ever " cat /proc/cpu " says and not the whole things physical cores dedicated to you its spun off a large blade cluster.
PS: Don't take me wrong , good you are playing around and taking advantage of the extra cores to give you a boost! Just want to help you get the best cpu usage and not get throttled and suddenly you OCT core goes 6 core @ 80% max cpu on its own.