Hi everyone,
about two weeks ago, I signed up for a VPS with a cloud provider and set up a Tor relay. I installed Debian 11 Bullseye, secured it, and then set up Tor 0.4.6.8 and started the relay.
The VPS had the following specs: 1vCore, 2GB RAM, 40TB traffic per month on a 1Gbit/s link. I throttled the traffic accordingly so that the monthly limit of 40TB would not be exceeded. Nevertheless, the CPU load was extreme, the server was running at full capacity and crashed several times.
Since I want to help the Tor network with a fast relay I now signed up for a root server  which has the following specs: Dual core CPU, 8GB ECC RAM, 2,5Gbit link, 1Gbit guaranteed, unlimited traffic.
I set this thing up with Debian 11 Bullseye again and Tor 0.4.6.8. Since my bandwith gets throttled when I use more than a certain amount of traffic/month and at the same time (!) on average more than a certain amount of bandwith for more than one hour, I set the MaxBandwith to 1000Mbit/sec (equals 125MB/sec).
This relay is up and running for a few days now, and I already have around 4000 incoming and outgoing connections. My bandwith is not fully used yet, but sometimes I see spikes of 20MB/s. What concerns me is that the CPU load again is sometimes 40-50% on both cores, even though this relay is not fully used yet. 
Can somebody tell me if it is even possible to run such a fast relay on this hardware?
Should I set a more restrictive bandwith throttle myself, or go for a quad core CPU?
I don't think I will ever run out of RAM this time, since I have 8GB.
Thank you for your advice! All the best!