I was having a chat with a old friend of mine over it and apparently a HDD will need to be going at around 120,000 RPM, the whole thing covered in magnets, Made of "indestructible" metal and will require VERY advanced mathematics to proven't errors just to keep up with modern day SS Drives...
That's if it doesn't
A. Burst into flames.
B. Take off
C. shatter into millions and millions of tiny pieces of metal going 20 times faster then the speed of sound lol
You can't match the performance of an SSD with a magnetic hard drive. You may be able to match the transfer rate, but you'll never be able to match the access time, and that's by far the more important metric for tasks like booting the system and loading programs. A 20KRPM drive could, at best, have an access time that's twice as fast as a 10KRPM Velociraptor - but SSDs already have access times that are 50 to 100 times faster.
My guess is that WD is seeing a declining market share for their high-performance 10K and 15KRPM drives as people turn to SSDs for performance-critical storage. They've probably realized that a 20KRPM drive would be a white elephant.
^yeah, price is what's keeping HDD alive right now.
It's going to keep HDDs alive for the foreseeable future. HDD capacities are improving just like SSD capacities are, and they have huge head start capacity-wise. It's going to be decades before SSDs catch up, if they ever do.
We'll be using SSDs for fast, limited storage and HDDs for cheap bulk storage for many, many years. The big change is that within a few years SSDs will get cheap enough to be used as the OS drive in virtually every system.
You also need to consider the commercial value of mechanical storage. Using an SSD for audio recording or graphic design, etc. would result in a very high failure rate and most likely loss of data, as these tasks require hundreds of thousands of writes, and overwrites. They also require a high consistent write speed for large files, which currently is only available in high RPM mechanical drives. SSDs have fast access times for reads and 4k read\write, but their standard write speeds are not better, and their failure rate is 100% when using them for certain tasks.