Large data donation (50M) causes server to become unresponsive temporary

[TjerkNan]

Describe the bug
High CPU usage for a prolonged period of time (half a minute) when donating 50MB of data.

To Reproduce
Steps to reproduce the behavior:

1. Use special feldspar application to generate 50MB of data
2. Observe high prolonged load on server when donating said data
3. Observe application being sluggish / unresponsive

Expected behavior

• Application stays responsive for users
• High CPU isn't a problem if user experience is not affected

Screenshots
N/A

Desktop (please complete the following information):
Safari

feldspar_load_test.zip