Digital Audio Workstations
Digital audio workstations (DAW) require an emphasis on stability, raw CPU horsepower, and hard disk performance. Computers these days do not have any trouble handling real time audio tasks, anything build since 2010 can easily track audio and add real time effects using commercial software. The limitation becomes support for modern OS and peripheral hardware to use the software you need for creating your music.
Depending on your principle type of project, you can emphasize different parts of your system.
In all cases, use a solid state drive (SSD) for your operating system. I no longer have patience for computers without them. Accompany your OS drive with large and separate secondary drive for your projects and samples. An SSD or a spinning platter HDD work find for that.
Real time live tracking and effects
CPU: More cores will be quite effective to distribute the load.
RAM: Not critical, as long as it’s stable and plenty for the OS
Disk: Any current disk will work fine. Only when running multiple 96k tracks or adding video workloads will disk performance become a concern. Use a separate physical disk from the OS installation.
Soft Synth Work
CPU: High clock speed and cache pay off more than many cores in many situations
RAM: The more the better, the samples will be stored in RAM for fast access so a 64 bit machine loaded with RAM will be the way to go
Disk: Again, any disk will do but an SSD will speed the initial load of your samples or help those that run straight from disk. You should add a third physical disk, one for OS, another for live audio tracks, and a third for sample banks.
My systems are no longer remotely new or notable in any way. Details removed to avoid embarrassment.
When this site was born back in early 2000, each successive generation of PC’s enabled so much more capability that I wanted to do. I had time for games, and gobbled up new processors and supporting parts to get a higher frame rate and more audio effects.
Somewhere around 2010, the capabilities of your average PC became sufficient to run all the audio I needed, and keep up with the old games I wanted to play and still hadn’t finished.
The fact is, for myself and most people, the PC’s in the last 5 years are good enough and I find myself using my trusty Surface Pro 3 for pretty much everything. That’s getting a bit old in 2020, but still functional and I’ll likely go for a new generation one when it kicks the bucket.