If you've got a spare minute or two try taking an EBS optimised ec2 instance and attempt to achieve those performance figures...
...and if you succeed please let me know how. Especially if you can do it two months in a row.
Cloud king Amazon has added two disk-drive-based storage options to its EBS (Elastic Block Store). There is a Throughput-Optimised HDD (st1) volume and a Cost HDD (sc1) volume. The sc1 volume is for low access workloads, coldish data, with a price of $0.025/GB/month while the st1 volume is for frequent data access to Big Data …
What instance type are you using? Not all of them can drive the throughput and since you're topping out at about 1Gbps that seems a likely candidate.
Glacier is unsuitable for backup as its not designed to allow data to come back, it's targeted at archival. S3 is orders of magnitude more expensive than the new cold option, which has been designed with use cases such as backup in mind.