No problem. Done. No problems found.
I used:
- RPi4/4GB running from a fast sandisk 64GB USB3 stick, booted from a sandisk cat 10 16GB micro sd card.
- Raspbian Buster with all patches. No swap (well, not a serious one: 128 MB)
- FPC version 3.3.1-r43569
- Lazarus version 2.1.0
- Offical USB-C Powersupply
Both FPC and Lazarus built from source on the Raspberry Pi itself.
Speed problems are often caused by:
- a 1 GB without enough swap
- a proper swap (equal to the hardware memory) but on a slow medium
- FPC and/or Lazarus built with debug information (never do that, unless you develop for the compiler or the IDE).
- Not updating Rasbian enough!!! There are almost weekly speed related updates. Plz run sudo apt update && sudo apt dist-upgrade -y if you did not do so already.
- An under-powered powersupply (RPi4 will throttle down!!! if starved, do you see the lightning image in the top right corner? That indicates not enough amps)
[edit]
Just repeated the test on a RPi 3b + 1 GB swap and there there is a noticable slowdown, but not unworkable.
That Pi is also running Pihole and a webserver, so there are less resources available.
This Pi has also the same storage configuration, except not running on USB3 speed of course. (stick and sd are the same, though)