If the issue is amount of pixels generated perhaps CPU cost increase would help; If the issue is delay in generation itself (as in - processing power and database power needed to add such pixel) why not simply delay pixel generation per player, and add internal 'pixels to generate' counter, and instead of generating them one by one, generate them in bulk e.g. every 20 000 ticks? This way system needs to modify the values in database only once every few - few dozen pixels instead of at every opportunity; Pending pixels could also be added as a counter [not usable by players until generated], and generated in bulk once e.g. 100 of them is prepared for generation.