I am trying to assemble a plant genome using AWS resources using velvet. Plant genome is huge (> 10 times human genome) and coverage is around 30 x. We are planning for de novo assembly with Velvet (threads enabled). I would like to know if there is a calculator that can provide approximate time taken for assembly, given the necessary details. For eg. if I furnish RAM, CPU (type of instance), genome size, approximate coverage, type of sequencing (PE or SE) and number of client nodes, it should give me the number of hours or days that would take for assembly (reference and/or de novo).