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PSU Wattage Question

Posted: Wed Aug 08, 2018 8:45 pm
by ark_angel
My current PSU Corsair CX600M has started making a clicking noise while gaming leading me to think it is probably time to replace it. I saw a deal for a EVGA 650 BQ which I tried but had to send back because the fan sounded like a Dustbuster. For my own sanity I want as quiet of a PSU as possible which has lead me to the CORSAIR RMx series. What i'm wondering is spending the extra money for a 650 or 750 keep the fan from kicking on at full speed worth it? My current max draw is around 450 but I plan on running i7-9700k or zen2, 1070, 4x8gb 3200, 3 ssd, 3 hdd when the next gen processors come out and probably upgrade my 1070 in a generation or 2.

Re: PSU Wattage Question

Posted: Wed Aug 08, 2018 8:50 pm
by Waco
A larger unit might be slightly less efficient at lower loads (though newer designs are much better in that aspect). I just go straight to Seasonic these days, it's the only easy way to guarantee the quality of the unit. I'd get a 650 over a 450 just to not have to think about it going forward.

Re: PSU Wattage Question

Posted: Wed Aug 08, 2018 9:05 pm
by DancinJack
Seasonic Platinum or higher for me. Platinum is usually 90%+ at 50% utilization, and their hybrid fan system is usually fanless until about 40%-50% utilization (depends on the model). I never hear my PSU fan turn on because by the time it does, my CPU or GPU fans are drowning it out. BTW, those Seasonic Platinums that I was looking at are 90%+ at 20% util, so that's pretty damn good for low utilization.

IMO you should shoot for a 650W or 750W Platinum. Again, this is just my preference so you might differ.

https://www.amazon.com/dp/B074N8RG74?th=1 - 650W Plat is a pretty good one to look at.

Re: PSU Wattage Question

Posted: Wed Aug 08, 2018 9:19 pm
by strangerguy
At the minimum get at least a PSU with a 10 year warranty like the Seasonic Focus Gold Plus 750W and don't bother with the cheaper units. PSU fan noise isn't really a problem since most gold and better offerings won't spin before 20% load and considering just how much whiny the much smaller GPU ones are at load.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 9:44 am
by DPete27
You've measured 450W at the wall using a Watt-Meter? That's nice, so you know exactly where you stand.
PSUs are pretty efficient these days, and their efficiency curves are much flatter across the duty cycle than days of yore. We're talking >87% at 20% load, >90% at 50% load, and >87% at 100% load.
For that reason, I don't think 750W (while more than you need) is bad in any way necessarily.

Sounds like you should be looking for a PSU with semi-passive fan operation. My favorite two are:
EVGA G3 - Their 650W unit is on sale for $77 after MIR. Advertised as fanless <20% load and reviews seem to support that.
Seasonic Focus PLUS (make sure it's the plus model) - 650W for $70 after MIR Advertised as fanless <30% load, but according to reviews that might go closer to 50% load...YMMV.

Looks like the 750W units from both manufacturers are sitting around $100. Also the Seasonic Prime Ultra 750W (with 12 year warranty) is discounted to $100 right now (until Monday). And the Seasonic Focus+ Platinum 750W is $105 after MIR.

From the reviews I've read, there's rarely much of a difference between 80+ Gold and 80+ Platinum PSUs in the same family, especially when they have similar cost and warranty. Most of the time, the gold units pass gold ratings with flying colors and the platinum units barely squeak by (keep in mind, we're talking 2% efficiency difference between gold & platinum). For that reason, I wouldn't put much weight into a Platinum-over-Gold choice. You really have to step up to the Titanium models to get a noticeable difference in platform quality/efficiency, but those PSUs get pretty spendy.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 1:49 pm
by synthtel2
^ Everything DPete27 said. ^

EVGA's lineup is weird because they sell a bunch of PSU platforms from different manufacturers under different names. The G2/G3 are great, but last I knew all of the others were fairly meh.

A 650W should be comfortable unless you're overclocking everything to the moon (even if you upgrade to a 250W GPU at some point), but there also isn't much reason to not go with a 750.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 2:36 pm
by wizardz
i'm in the seasonic crowd as well.
nothing but good things to say about them. maybe a tad more expensive than a Corsair/EVGA.

http://www.realhardtechx.com/index_arch ... abase.html <= here you can see a list of PSU, as well as the OEM behind it.
sometimes Seasonic is the OEM behind some model of Corsair/EVGA/??

hope it helps,

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 4:58 pm
by e1jones
I clearly don't have as much going on inside my computer. The computer itself is only 50-60 watts during my normal work day, and is probably closer to 180 watts when I'm gaming (According to my UPS anyway).

I have a 550w EVGA G2 that pretty much never even turns on the fan... same with the Gigabyte 1060 video card. I've never checked during a gaming session... the video card at least probably spins up.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 5:05 pm
by DancinJack
Yup, the 550W G2's fan turns on at about 20% load, but doesn't even hit 50% fan speed until 40% load. That's pretty close to how most decent PSUs work these days. I still maintain that Seasonic is the best choice, with the Seasonic made Corsairs/EVGAs being a close second.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 6:43 pm
by ark_angel
Thank you all for the advice. I ended up going with the Seasonic FOCUS Plus 650 Gold SSR-650FX 650W which was $90 from amazon.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 7:33 pm
by DPete27
Does the $20 MIR apply to Amazon? I don't see it even mentioned on Amazon.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 7:40 pm
by DancinJack
Doesn't look like the MIR is on there for Amazon. Though I don't necessarily blame the OP, MIR are almost always a huge PITA imo.

Re: PSU Wattage Question

Posted: Thu Aug 09, 2018 7:50 pm
by ark_angel
I had a $60 gift card at amazon and I've had bad experiences with MIR. One company claimed I didn't send in the proof of purchase (which I had no way to prove I did since they had it) another took over 4 months to process, etc.