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Comment by oavdeev | Hacker News Reader

Stock Ubuntu needs SR-IOV driver to get to the actual bandwidth limit on ec2, it makes a lot of difference. We routinely get to ~2 Gbps down from S3 with that setup (using largest instance types).

edit: Gbps not GBps

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That's true, although the latest stock ubuntu HVM AMIs (14+, I believe) have the SR-IOV driver already and use it by default. Older AMIs need to have it installed and enabled on the AMI. I believe enhanced networking is only available on HVM amis.

This problem definitely existed with official 14.04 (HVM) AMI, though I haven't re-tested this recently, they may have fixed it. It did have some kind of SR-IOV driver but it was too old.

Good point for "enchanced networking" instances. I didn't see OS specified in the article. AMZN linux would have SR-IOV driver by default. PV vs HVM might also have an impact.

Per the comment here [1] and the linked twitter convo, I'll retest S3 with Amazon Linux soon. These tests used Ubuntu 14.04 on all providers, and did use HVM. My understanding is that this will possibly increase the network throughput of the VM, but the benchmarks stayed below the VM's capacity (which was the reason I included the charts of VM throughput).

[1] https://news.ycombinator.com/item?id=10846497

Couple of other points:

1. Enhanced Networking (SRIOV) only works in a VPC and not in EC2-Classic.

2. I think the 4x instances don't support 10Gb ethernet. If that is the case, it would also be instructive to test the 8x instances on S3.

For some very application (Hadoop) specific tests of Enhanced Networking, please take a look at https://www.qubole.com/blog/product/hadoop-enhanced-networki...

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