Tor relays in the Amazon cloud: usage charges

I recently found out about Tor Cloud and think it’s a great idea.

In a nutshell, you can strengthen the Tor network with a few clicks and a small amount of money paid to Amazon.

But how much does it actually cost to run a Tor relay on Amazon’s EC2 service?

Here is what I’m paying after one month of running some Tor relays in the Amazon cloud:

Data Centre (location)	EC2 instance running time		Bandwidth used			Total running cost per instance for one month (USD)
	Hours	Cost (USD)	GB in	GB out	Cost (USD)
California	744	18.60	2.774	2.457	0.29	18.89
Oregon	742	14.84	0.517	0.194	0.02	14.86
Sao Paulo	741	19.85	37.644	21.603	5.40	25.25
Singapore	744	18.60	0.853	0.596	0.11	18.71
Tokyo	744	0	11.873	11.267	2.26	2.26
Virginia	744	14.88	0.828	0.543	0.07	14.95

Remember that there is a “free usage” tier – this probably explains the $0 running cost charged for my Tokyo instance.

Conclusions from the above:

1. Maximum bang for the buck if you can’t spend money on this: Run only one instance, preferably in a high-traffic area like South America. Expect to spend less than $10 per month.
2. Expect to spend approximately $20/month/instance if you’re running more than one instances.
3. I’ll kill all instances but Sao Paulo and Tokyo – at the moment all other instances seem to be receiving so little traffic they’re not worth the hassle.