It depends on your workload, does it not? Generally you'll want swap to be mostly unused, so you don't need a lot, but if you want to eg. hibernate a laptop, yo

It depends on your workload, does it not? Generally you'll want swap to be mostly unused, so you don't need a lot, but if you want to eg. hibernate a laptop, you'll need at least as much as you have RAM to do it. Also If you use tmpfs you should have enough swap to cover the size of your tmpfs partitions in their entirety so that a bad application won't eat all your memory.