Way smaller in scale and I think the mechanical, factory like killing of Jews (and other groups) is a lot darker. Although all of them horrible the other usually were made up of mob killings carried out by civilians and soldiers - rather than them all being taken to camps and gassed then incinerated. Also helps it was during the biggest global conflict.

Believe it or not to this day many historians, political scientists, and legal scholars are still arguing over what should be the definition for Genocide? The United Nations definition for Genocide found in Article 2 of the Convention on the Prevention and Punishment of the Crime of Genocide was carefully crafted so that actions committed by or being committed by members of the security council were omitted. While historians such as John Cox stress that all this arguing is taking away from the time that could be spent on researching, and documenting human rights violations.

In regards to the Armenian Genocide it happened in 1915-1917. Although the idea for a concept of The Hague came about in 1913 it never came to fruition until 1945 when the United Nations was conceived. Sadly when it comes to international law you can't truly have a trial unless everyone agrees to it. So, as long as Turkey keeps playing the 'Don't look at me, I didn't do it' act. Nothing is going to happen, any time soon.

I'm actually concentrating on middle eastern history so I apologize, that my knowledge on the Rwandan Genocide is rather lacking. If memory serves me correctly perpetrators on both sides were actually tried both in the United States, and France.