125+% on 2GHz Core i7, and CPU temp is at or near 100 celcius.
The point here is simply that people with computers of all different power levels are using your forum. Implementing an annoying background effect that is processor intensive is illogical. This forum's maintainers should be thinking of their audience, not themselves. People with computers far below that of mine or OP's will be visting this forum, and that must be taken into account when designing the site. If I want to see snowflakes, I'll look outside, not at my computer.
Also, what about people visting here from anywhere that doesn't get snow? Again, not thinking about their audience!