Hi, looking for advice on selecting components for my dream Linux Puredata machine.
-Ubuntu Studio, maybe an RME PCI card
-Really only doing audio (oscillators, arrays, filtering, delays) No graphics.
-Lots of MIDI and OSC.
-Keeping the the machine quiet (low fan noise) is VERY important.

What CPU specs matter most for common audio and MIDI tasks in PD? Number of cores? Thread count? Clock speed?
If I run other apps (VCV rack, Carla, various Jack plugins) will those processes distribute to the other Cores?

Does Pd benefit from a more powerful GPU card? Or will there be no difference if I use the GPU embedded in the CPU? Is it different if I launch Pd without the gui? (-nogui)

Thanks for any advice. I want to build the most powerful machine I can, but I don't want to waste money on extra specs that won't result in better performance.

Ed

@cheesemaster I don't think much matters with a modern computer.
This is interesting for Linux...... http://puredata.info/docs/faq/how-can-i-run-pd-with-realtime-priority-in-gnu-linux/?searchterm=linux audio but as it says...... probably out of date now with Jack.
You can set realtime priority for audio in Linux..... which helps a great deal..... but unless to are running [pd~] as well to spread load across cores Pd will only use one.

I have 6 Toshiba I5 Notebooks..... this.zip
that do everything for me on shows including running video and Pd at the same time with wireless osc control.
But I also have an I3 HD3000 machine (same model) that I run a show monitoring system on...... Pd based with massive amounts of OSC and monitor mixing and backing track playback........ in windows..... with no problems.
I paid $100-$200 each for them on Ebay.
However....... the fan noise is not great...... so don't buy any of those for your use.

Large RAM can be useful, and an SSD obviously, but processor speed is irrelevant for audio nowadays.
Ports...... USB...... more than one on-board hub..... because if you connect a USB1 device to the same hub running USB2 audio it will knock the whole hub down to USB1.
USB2 is enough for at least a 30in 30out soundcard...... avoid firewire as it will break expensively at some point.

Beware of Wi-Fi cards that could behave badly causing interrupts and so clicks.... that might not be true in Linux though..... but do some research.
Again..... USB...... Macs connect their keyboards and cd drives through an onboard hub so it is essential that they have a second one free for any soundcard. If they have a USB3 then that can be used for a USB2 soundcard though.

Native instruments only had advice for windows before, but have this for OSX...... which could be relevant being UNIX....... https://support.native-instruments.com/hc/en-us/articles/210296445-Mac-Tuning-Tips-for-Audio-Processing
David.
P.S. @Eeight has just come on line and is an expert so.........

Yes and a topic that I like very much.
We're in 2020! Like I always say, we sent a spacecraft to the moon with a 2.048 MHz computer

@cheesemaster said:

-Ubuntu Studio, maybe an RME PCI card

Why RME PCI, you can find good external soundcard, I guess it depends on the computer that you will choose (more on that later). Yes I like Ubuntu Studio, good choice.

-Really only doing audio (oscillators, arrays, filtering, delays) No graphics.

Perfect, start pd with -rt -nogui
Use [pd~] only if topping 100% CPU (pd is single thread).

-Keeping the the machine quiet (low fan noise) is VERY important.

Fanless is possible, again depending on the computer you choose.

What CPU specs matter most for common audio and MIDI tasks in PD? Number of cores? Thread count? Clock speed?

Clock speed = lowest latency (you can push jack to buffer 64) without xruns. If you are not playing live (for example using ADC) you don't need low latency configuration (I am lucky and not very good at detecting latency, my setup is around 38ms (round-trip). You can detect latency using jack_iodelay.

RAM is important if you want to load samples in PD in advance (avoiding glitches).

NVMe SSD if you can.

If I run other apps (VCV rack, Carla, various Jack plugins) will those processes distribute to the other Cores?

Yes, again Pd is single thread. Others are usually better (GUI on a separated thead for example).

Does Pd benefit from a more powerful GPU card? Or will there be no difference if I use the GPU embedded in the CPU? Is it different if I launch Pd without the gui? (-nogui)

If you don't use Gem you don't need a dedicated GPU card.

Here's some ideas for you, I've been building some setup over the years:

Theremin à crayon:

Using a Surface Pro 3 running Ubuntu Studio with a "old" USB 1.1 sound card. Heavy patch using lots of software : Bitwig, SooperLooper, Guitarix and of course PD. Midi (PD), OSC (Bitwig, SooperLooper). Very quiet but the Surface gets hot (fans are kind of quiet like a good laptop).

Heavybox:
https://www.workinprogress.ca/projects/heavy-box/

Similar setup, a quiet PC using a big heat sink and a overrated power supply so the fan never start. Noctura fan on the side (expensive but quiet). Old soundcard (firewire) but I can do low latency. 8 ins/8 outs.

Biscuit box computer:
https://www.workinprogress.ca/biscuit-box-computer/

Mini-pc not quiet, not very fast in this case a cheap usb soundcard (you know +- 8$ barely better than the embedded one).

Phimatics:

A raspberry pi 2 with wolfson audio card. Using only PD with Alsa, I am getting very good result (low latency) quiest setup. But of course I need to be careful with the CPU.

JAS:

Working on a new project, I found this midi keyboard in the trash / snow. I will put Khadas VIM version 1 (ARM) with a BEHRINGER UCG102 (usb soundcard for guitar). Quiet, no fan can be run on a battery (5V). Will post the project when over.

Lattepanda:
Never worked with it, but looks very powerful. There's a price tag. Maybe for the next project.

Cheers

@whale-av Thanks, that's good info regarding the USB busses.

@EEight- Lots of good info and I love that biscuit box PC!!

I have a nice laptop with a touchscreen, but the fan gets loud under load so I'd like to move the audio stuff to an external machine and "remote control" it with OSC, VNC, and or SSH. Keep the graphic/Gui side on the laptop.

I like the RME PCI cards because I've used them a lot with great success on Mac/Win. I'm hoping this box can also be semi-portable, so minimizing the external components is a design goal.

@cheesemaster As has been said, pd has little use for a GPU unless you run gem, pd seems to be its own limit on graphics and bogs down long before the computer even notices. Dumping the modern big DE's, like Gnome and KDE, will greatly reduce your need for a GPU, use one of the lightweight DEs like LXQT or XFCE, or just a window manager and you will be able to get by with most anything. VCV rack may be an exception, my i4 with nothing special intel graphics had some issues with it, but I suspect that was actually a bug and not a graphics issue, VCV was brand new and bug ridden when I tried it.