Was the genocide in the Holocaust the worst genocide?

All genocide is horrific but the sheer scale and size of the holocaust as well as the industrial efficiency of killings of the Nazis makes it stand out. The Germans were very organised and had archives and infrastructure for the action, which has simplified proving the crime, although they tried to keep it secret for the general population and others outside the SS leadership. In the reports natural death causes were stated, or S.B. for "Sonderbehandlung".

There have been other large scale genocides, but less documented.
Also mass killings of people of the same ethnic group, which isn't a direct genocide, have occurred. Estimates suggest that Stalin was responsible for more killings than Hitler.
The genocide in Rwanda resulted in 300000 killed/month which is a much higher killing speed than the Nazis', and a much larger part of the population was involved in killing with their bare hands.
Genocide of Syriacs, Armenians, Greek, Kurds, and others are modern examples.
Historically there have been many genocides, and the stronger parties haven't had much interest to describe the details about their crimes.
The amount of native Americans that died as a result of European colonisation is many times more than the kills in the Holocaust, but there is no record of any "murder factory for Indians".