How much faster is a render farm?
As a rule of thumb, CGI images take roughly an hour per frame to render. This figure has remained roughly constant over two decades, in spite of huge improvements in computer processing power. The reason for this is that advances in computer power are absorbed by increased computation in order to meet demands to achieve state-of-the-art image quality, whilst the hour-per-frame figure arises from the demands of production timescales. The use of render farms in the entertainment industry can be viewed as one early application of grid computing.
