I tend some workloads that transform data grids of varying sizes. The grids are anon mmaps so that when mem runs out, they get paged out. This means processing stays mostly in-mem yet won't abort when mem runs tight. The processes that get hit by paging slow to a crawl though. Getting faster SSD means they're still crawling but crawling faster. Doubling SSD throughput would pretty much half the tail latency.