Official comment
@Mike > Personally, I have a mid-2012 with an 8-core i7 2.3GHz, 16GB RAM and a 256GB SSD and it runs like stink. When I have rekordbox 4.3.0 running idle in performance mode (no video, no dvs, no FX, no sampler), it sits around 26% CPU activity. When I have 4 tracks running with FX, CFX, and sampler open, it still only squeaks up to 56%. Add video and DVS modes (only playing audio) it's only up to 61%. Make those videos and it bounces between 80 and 105%. Keep in mind, I can crank up to 800% CPU as the max thanks to 8 cores, so really, it's not that high in terms of usage... and I'd never have that much stuff open all at the same time (or 4 videos playing all at once).
But! Launch into the rekordbox 5 beta, and the exact same "maximum use scenario" as above on the same computer is running 60-85% CPU. They've done some fantastic work on the back-end to improve the performance and decrease the workload. By the time v5 is at official release, I'm sure they will have tightened the bolts a bit further.
Bottom line ... can you run rekordbox on that 8 year old computer? Yep, but I'd recommend disabling everything you don't need, not just in rekordbox, but all the other background tasks on the computer that may be sipping resources. Not to de-rail your hopes and dreams of using that computer well into the next decade, but it's already 8 years old, how much longer are you planning on using it as your primary machine? In general, if you get 5 years out of a computer, it's done well (and 8 years is on the outside of what you should expect to still have decent performance - a MacBook Pro will certainly still be doing better here at 8 years than the majority of PCs!) And if you're working as a DJ making money using that computer, it's a business expense and you should really have replaced it already.
