Results analyzed and comparedHere is a quick recap from the results nicely put in graphs plus the results we obtained in our
preceding article. We start of comparing the efficiency of the 7 competitors, all rated 80 plus they should give us quite some decent scores, and off course that is what we got.
Optimal efficiency is obtained at 50% load, here we see all power supply's score very good with over 85% efficiency. At 300W load this translates into 45~52W power consumption inside the power supply. Overall we noticed the CoolerMaster, Zalman and Sharkoon power supply to be the most efficient, slightly trailing behind are the OCZ, Enermax and Nexus psu's with Scythe's Kamariki 4 closing the pack. Though in each load test the efficiency percentage difference is so small you can hardly speak of a winner here, at best the Scythe is being topped out by
only 4%, don't forget there's also something called sample quality and 'stepping', even with power supply's.
Inrush current
Inrush current measured with Tektronix DPO3000 Digital ScopeInrush current, or, the current which is drawn when the unit boots up with full load, hasn't really been tested in the past, it was when manufacturers noticed that the power-on/off button at the back of the PSU got damaged because of high current flow that people now are starting to focus on what inrush current in fact is. From our result below we see CoolerMaster doing a pretty good job scoring nearly 10Amps less then the OCZ and Scythe psu's, but it's the larger Zalman/Sharkoon/Nexus psu's which scored really high here probable due to the extra components. High inrush current might damage low current rated components like the on/off switch; in some high-end power supply we no longer see these power button. Furthermore with high inrush current you have a chance of decreased component life as they're being stressed more. One of our sources told us Intel has put the maximum at 100A inrush current.
Standby power consumptionIn standby power consumption they're scoring very low, none of our samples using more then 2 Watts in standby we have again 7 winners here:
For most global brand PSUs used capacitors can be found from numerous other reviews but for European PSU brands thorough reviews aren't so common.
While looking all good now PSU with crap capacitors can easily go bad after only couple years (or faster) so use of known high quality capacitors isn't just PR stunt. Instead of el Cheapo products even PSU with more average performance, say in voltage regulation, but high quality capacitors, is lot better investment and can keep going lot longer.