RTOS comparison info needed


I’m looking for an article or URL that compares several RTOS products. I’ve
found some by searching industry rags, but the articles have all been
industry specific (i.e. RTOSes in the Automotive Industry). What I’d like
is a more general comparison of RTOSes using several benchmarks (ROM and RAM
use, CPU usage, interrupt latency, etc.) Does anyone have a good reference?