Too Long; Didn't Read
Dashbird has released a Lambda benchmarking benchmarking tool for Lambda. The code is open sourced, in case you’d like to test your own Lambda functions. The results presented below will certainly vary according to the function you test, so I encourage you to download the Benchmarker Lambda and run it for yourself. The sweetest spots in terms of cost were 768 MB: that’s the cheapest memory we can get for this task on Lambda. 768 MB can actually lower our AWS bill by increasing memory size in some cases.