For each of the basic traffic tests in the system test suite, specify different payload size. Use small range 0-10K for the samplecc traffic patterns, and use different test steps to send a few messages with larger (maybe 4MB and 49MB) proposal payloads with fixed payload size. Remember the payload size is injected into the proposal; the proposal response and the transaction submitted to orderer will essentially be double that size (up to 98MB). Run these testcases on all three networks (kafka_couch, kafka_leveldb, raft_mutual)
As part of this we should make all the traffic tests run approximately the same duration, so they can later be run simultaneously and can be expected to finish about the same time. For now, recommended time length around 20 mins. That should require more than 10,000 TX per thread, except when using large payloads exceeding 10K, (especially when using kafka) because it takes much longer to handle huge transactions.
Note the SBE and marbles chaincodes ignore the payload size parameters. Use samplecc, samplejs, mapkeys, or other chaincodes that honor the parameter.