It's taking a long time to apply some of the filters/effects/plugins in my projects. I often use a second computer and let it process there while I continue to record or edit on my main system. Sometimes I turn the monitor off and leave it in progress overnight. I've done all I can on the recording side to reduce the time it takes to run my chains, so at this point it's a hardware issue. I've searched for performance tips, but the only useful page I found was from the Windows ME era.
It's worth my while to buy or build a new Linux system specifically for audio processing, since this is still cheaper than buying real-time hardware effects (at least, as far as I know... maybe not?), and I prefer to preserve the raw audio anyway, then apply filters and such later in a copy of it.
Anyway, what are the hardware performance bottlenecks for Audacity effects? I realize that there may be two or three different answers to that, depending on the kind of effect.
I use 64-bit Linux, so RAM isn't much of a limiting factor. All modern CPUs are multi-core, but I don't know if Audacity and its effects systems and dependencies are multi-threaded. If they aren't, then I guess I would need a CPU that does single-threaded performance really well. That could be difficult to figure out, since manufacturers haven't been focusing on single-threaded performance in a long time. Is it possible to use other hardware, like a video card or good sound card to offload some of the processing? I've already got a decent SSD, but if I bought 3 more and set up a hardware RAID 0+1 configuration, would that significantly improve performance?