…writing becomes slow. Not reading… reading is always the same speed, regardless of fill state.
Reading only becomes slower under a condition called “steady state”, when the SSD has to perform a lot of background operations, but this is mitigated by good controller chips.
Usually, under sample playback conditions, write speed is almost irrelevant. Whats important is the random 4K reads @ QD1 performance (sadly software companies don’t optimize for higher QD yet, it wouldn’t be hard, but there is a special brand of software engineers who stopped learning at some point and think that the hammer they used in 1992 is still good for the nails of 2014) and, for larger samples, sequential read performance.
Write performance? Thats something I consider neglible, except for extreme multitrack recording (recording a lot of tracks at the same time - not the usual “this guitar here, this keyboard there” at once). And even those harddisks were fast enough for recording many, many tracks at the same time. Even the slowest SSD beats the fastest HDD at any time, so…
Besides large samples, for usual use in a DAW (or a gaming machine, etc…) the “sequential read performance” is mostly for benchmark kiddies, it doesn’t really reflect real life performance.
Because of the laziness of many software engineers, the most important value is still “random 4K reads @ QD1” - which could be “QD32” in many cases (ESPECIALLY sample playback - and you usally get an order of magnitude, or better, better performance with a filled queue, but software companies more often than not simply don’t care about this simple, almost trivial, optimization), but software engineers would need to do their homework, and, more often than not, they simply don’t, because “oh, it works like this and I learned it like this, back in 1992, when Win32 and dinosaurs ruled the Earth, what is a thread anyway and stuff”.
Sad, but true.
I’m not sure what Steinberg do, actually I’d say that they have really clever guys in software engineering, so I would actually think that we get nice QDs from Halion and similar software, so they are not to blame, I think, because Halion also loads samples super fast (from my 2x Samsung 840s in RAID 0, spread over 2 different controllers, almost instantaneously in many cases).
Also, the CTO of fxpansion told me that they load large chunks (which is also good for SSDs) in their software, especially BFD 3.0.
However, there are too many “Morts” (http://blog.codinghorror.com/mort-elvis-einstein-and-you/) out there in many, many software engineering teams. Usually the guys who solve problems for the very moment but their solutions are neither future proof nor maintenance friendly - and not even remotely modern.