I need an advice in choosing new PSU

Hello,

My backup computer's PSU (Enermax Triathlor 550W) was malfunctioning and after warranty service check it was beyond repairs. Since this model was not available for sale anymore they offered me to choose a new one from my retailer shop and pay the price difference.
I have two choices: 1) pick less expensive for backup PC; 2) pick good one for main PC and move it's PSU to backup PC.
My main PC has Enermax Platimax EPM600 AWT model and using Enermax PSU calculator recommended minimum PSU wattage is 377W. I plan, however, upgrading it's video card in the future, but the model GeForce 960Ti is not released yet (if ever will be) and when I use GeForce 970 in calculator it says recommended power 450W (542W in SLI mode).

Retailer shop, where I can pick PSU from, has poor choice of Enermax PSU, they are either bronze or gold certified and only platinum they have is 1350 watt. I don't want to pay extra for watts I won't use, but I prefer extra 30% for unforeseen circumstances and wearout, which would be 700 watt or around.

There are other known brands like Corsair, Cooler Master, etc., but I am unfamiliar with their PSU.
I've made calculations and difference between bronze and platinum would pay off in a year.
From experience, all kind of circuitry protection is important, like over-voltage, under-voltage, over-current, short circuit, etc.
Lastly, from what I have heard, active Power Factor Correction is better than passive, but I don't really know why except better power efficiency.

Basically, I need power efficiency and safety for main PC and safety with small power efficiency for backup PC.
You can visit my retailer shop web page to check available models, but it is in Latvian. You can try Google translate the web page, but unfortunately, filter doesn't work in Google translate. Here is the link Barošanas bloki (PSU) :: Datoru komponentes :: 1a.lv

I appreciate any advice, since PSU is most important part for healthy computer.

Hi,
Personally I would get a EVGA model either a P2 if you can stand the price or G2 version of what ever wattage you want too,
I just sent back a RM850 because it just looked cheap and so did the wiring I wouldn't expect any improvements in lower wattage units from Corsair.

Most if not all psu's will have safety features.

Hi,
In comparisons in price evga's are more reasonable than Corsairs in any flavor.
Cables alone evga is better and more versatile.

The Platinum, Gold, Silver, and Bronze ratings have little to do with quality. It's just an efficiency rating.

The online calculators are notoriously inaccurate and typically tell you to buy more than you need because they need to allow for the fact that you might pick a poor quality PSU that can't reliably deliver its stated capacity.

The Corsair AX and HX series are good, made by Seasonic the last I checked.

I'd get the cheapest one of those models I could find between 500 and 600 watts. That's plenty of power for any single video card.

If you might go to 2 video cards, then maybe go above 600 watts.

I did the calculation on how much improved efficiency saves.

If my PC is on 13 hours a day, 365 days a year, each percent improvement in efficiency will save about a dollar a year, given an electricity rate of 15 cents per KWH. That's for a PC that normally uses 80 to 100 watts measured by a Killawatt meter and occasionally uses up to 140 watts.

If you pay more for power, or actually use more power than that, or leave your PC on more than 13 hours a day, you'd save more than I do. Convert for your usage, your power rate, and your currency.

Hi,
Just for the record the RM850 is a gold certified psu and what the retailer was supposed to have so that is why I mentioned it
It is supposed to be on a set ECO mode but also as other models have a corsair link software utility to fine tune I suppose.
Whether other gold certified models are available or RM850 or lower you have not said which exact models the retailer has.
Also a Limited 5 year Warranty

EVGA P2 and G2 models have a ECO switch.