The RM650 has at its core a very well designed board, its ripple suppression, amperage outputs, voltage regulation, voltage and amperage over protections are all on a level with the class 2a Seasonic made units, so ranking the RM650 as 2a is easy, basically it's an excellent unit. It's problems stem from case design and poor choice in capacitors and thermocouple. It is designed with a passive use in mind for low output during idle, simply, the fan doesn't spin and the corrugated case acts as a heatsink. Most psus have reliable rated output upto @40°C, some as good as 50°C. But thats overall inside case heat, not heat as registered at the capacitors. Most caps in high tier psus are the 105°C Japanese solid caps, extremely well made and durable. the RM series uses cheaper 95°C caps on its secondaries, still good caps overall, but not to we'll thought out considering there is no airflow for low load usage. All of this relies on a thermal switch to turn on the fan and cool the unit once loads reach a certain output and the temps in case rise. This is supposed to be @30°C, I believe, but with slight dust accumulation and a poor switch implementation, this could get to as much as 40°C in case temp, with the secondaries providing most of the heat, basically coming close to their rated temp max long before the fan kicks on.
Turn that switch off and run the psu in normal, non-silent, fan always runs mode, and the RM650 is a tier2a psu just based on its outputs alone, which should easily run your cpu, OC, gpu with some headroom to spare. Leave that switch engaged, running in silent mode, with a 200w+ cpu and possible above average case temps etc etc etc, and you end up with a tier 2a psu with a possible very short lifespan simply due to bad thermal regulation at the psu level.
So, yes you shouldn't have any worries about power needs, you won't be running the psu close to max rated, but please be careful with the temps (orient the psu to draw fresh air, not case air etc)