Comment Re:Reliability (Score 2) 438
Depends on the application. For a workstation or build box, we configure swap on the SSD.
The point is not that the build box needs to swap, not with 32G or more ram, but that having swap in the mix allows you to make full use of your cpu resources because you can scale the build up to the point where the 'peaks' of the build tend to eat just a tad more ram resources than you have ram for (and thus page), which is fine because the rest of the build winds up being able to better-utilize the ram and cpu that is there. So putting swap on a SSD actually works out quite nicely on a build box.
Similarly, for a workstation, the machine simply does not page enough that one has to worry about paging wearing out the SSD. You put swap on your SSD for another reason entirely... to allow the machine to hold onto huge amounts of data in virtual memory from open applications, and to allow the machine to get rid of idle memory (page it out) to make more memory available for active operations, without you as the user of the workstation noticing when it actually pages something in or out.
A good example of this is when doing mass photo-editing on hundreds of gigabytes of data. If the bulk storage is not a SSD, or perhaps if it is accessed over a network that can cause problems. But if the program caches pictures ahead and behind and 'sees' a large amount of memory is available, having swap on the SSD can improve performance and latency massively.
And, of course, being able to cache HDD or networked data on your SSD is just as important, so it depends how the cache mechanism works in the OS.
So generally speaking, there are actually not very many situations where you WOULDN'T want to put your swap on the SSD. On machines with large ram configurations, the name of the game is to make the most of the resources you have and not so much to overload the machine to the point where it is paging heavily 24x7. On machines with less ram, the name of the game is to reduce latency for the workload, which means allowing the OS to page so available ram can self-tune to the workload.
-Matt