this could make your code faster by providing more consistent control flow: the main thread is always doing Work and your gc threads are always cleaning up dead

this could make your code faster by providing more consistent control flow: the main thread is always doing Work and your gc threads are always cleaning up dead objects. this provides fewer, better-predicted branches and code that's more likely to stay in the icache. most gc based environments use dedicated threads for gc and finalizers, this is one reason to do so edit: to be more specific: your normal flow is to alloc at the top of your function, and at the bottom you dealloc. so in basically every case you are paying the cost of deallocs, but if the alloc is conditional the dealloc is now also conditional which is more branches to predict. the dealloc is probably also handled by functions so you have jumps/calls eating up branch prediction table space in the gc/offloaded dealloc scenario, your deallocs on the work thread are no longer conditional because you're just handing addresses off to the gc. if your gc is STW you've added 'if (stop_requested) stop()' branches throughout your workload, but those are effectively 0-cost because stop_requested is always false (when it's true, the cost of the mispredict has no significance because your thread is about to suspend). the gc thread is always doing the same thing or waiting, and again when it's about to wait a branch mispredict cost has no significance.