Im running a pihole on rpi1vb for a year now. Wanted to have an backup, just because why not.
im having it run on a RPI 4 2GB. As u can see the loadavarage is real different.
Yes i run a LCD on a FPCB driver, but i can’t imagine that will get these loads.
Both run DietPi 32bit latest editions. I maybe installed the RPi1 with the curl script and the RPi4 with the dietpi-software. The RPi is running on a SSD.
Does anyone know what i can do to reduce the loads on the RPI4 (left)
I don’t see anything consuming too much cpu on the RPi4. Since the uptime is 4 minutes only, most likely there were a lot of things running together to boot it up. Wait a while and it will gradually drop.
yes, during startup an apt update is executed causing some load. If you are quick enough you can see it running by using htop right after boot/login
One notable difference is that on the one machine, Pi-hole was installed via dietpi-software, including the dedicated PHP-FPM server, while on the other machine it seems to have been installed via the Pi-hole installer, using PHP-CGI. Would be actually nice to see long-term comparisons of both in terms of RAM usage and CPU time after some longer runtime 
.
And yes, a few minutes after boot there is no chance to do a reasonable comparison. Give it 24h at least 
.