We recently added support for RavenDB on Linux ARM 64. You can get the new build here:
The nice thing about ARM64 is that when you run on AWS, you can use A1 instances that cost 48% less.
Oh, and what about the performance? This is RavenDB running on a1.large instance (2 cores, 4 GB RAM) with a standard gb2 hard disk with 100 IOPS.