[talawahtech]

There are number of issues with this report. The AWS networking section is particularly problematic and in need of extensive disclaimers or changes to the test methodology.

On the throughput side, all this test does is demonstrate the documented[1] throughput limit for a single TCP connection. 10 Gbps if the two instances are in the same placement group and 5 Gbps otherwise. The reason some of the network-optimized instances were "slower" than the non-optimized ones was because it was simply a random draw of whether both instances in the test were physically close to each other.

If they wanted to do a proper throughput test they would have used placement groups and multiple connections/flows. If they felt like the single flow test case was important they should have mentioned that AWS has a specific limitation around this. Personally I don't think a single flow test case is particularly realistic.

The fact that the obvious discrepancy between their results and the documented (multi-flow) limits didn't cause them to dig deeper is enough to make me very skeptical of the purpose of this paper.

The latency results are also basically a random spread. It is essentially distribution of all the different latencies you might randomly get between two instances if you don't use placement groups. It says absolutely nothing about the networking capabilities of different instances used in each test.

1. "Single TCP flow is limited to 10 Gbps for instances in the same placement group and 5 Gbps between instances anywhere else." https://docs.aws.amazon.com/whitepapers/latest/ec2-networkin...