... at what amount of load do you start spreading the footage to separate disks for reading spead and timeline performance?
So many variables influence this.
When adding 8+ hours 4K camera, GoPro and phone video to my low-to-medium powered laptop (with an SSD), playback was fine with no FX applied. The main downside was longer loading time the longer the project got - but playback was still good.
When transferred to my better spec'd desktop, I chose to break the project up into 5 different projects - each based on filming locations - to do rough editing and adding FX including color grading via the CGP before combining them back into one project at around 2.5 hrs in length for fine editing and matching with the VO.
If using all SSDs rather than any spinning disk HDDs, I never thought that using different disks would make much of a difference especially since SSDs don't rely on a mechanical search method as occurs with HDDs.
just curious, at what amount of load do you start spreading the footage to separate disks for reading spead and timeline performance?
I hardly see a performance difference between 4k50 media located on my SSD or 4k50 media located on my HDD. Just importing and loading projects goes faster when media is located on SSD. While editing and rendering I see no difference, I always render to a designated HDD, so not to the drive where the media is located. IMO, the bottleneck isn't the speed of the drives, but Vegas itself.