Power Supply Choices

[Bucic]

Because no pc components run at full load all the time, all together.

That, plus if it's a purely gaming rig, games don't put anywhere near 80% of what a synthetic load tests do.

 

PS. Some geniuses give total system power draw and put it in charts described as "GPU Power draw".

Edited September 23, 2015 by Bucic

[BitMaster]

Almost every PSU on the market, including really cheap ones, are of the switched-mode type. It's been like that for at least a decade. You can assume that anything I have been writing applies to switched-mode power supplies.

 

 

 

The 80+ certification only looks at loads between 20 - 100%. It doesn't tell us anything about the efficiency below 20%, which in your case with the AXi1200 is 240W.

 

If your idle is 145W, then you are below the break point where the efficiency of your power supply goes down.

 

 

 

 

With 800W I'm pretty sure you already have overclocking headroom even for a machine with two powerful graphics cards.

 

 

Switched vs. digital, I might have mixed those two up, sorry, my bad.

 

My Corsair Link SW says that my current as-of-right-now eff is between 82-88%, with a mere 90watt load input wattage and mid70s out.

 

If I dont game i run multiple VMs and power consumption rises pretty quick with a few guests running ooOOPS JUST FIRED UP Suse 13.4 and Ubuntu 15.04 and directl catapult the system into 180+Watt and plus 90 eff....

sure, if they all idle, nothing moves watt wise, but install updates on all OS's means all cores fly, all RAM is used and all HDs and SSDs are at work and I can still work with a very very low noise pollution and high eff. while it still just flies .)

 

Sure, the 1200er is a bit overdone but it was on sale for 80% price and I pay w/o taxes, so I payed for my 1200 what other may pay fopr a 850 AXi, which would just fit it now but had no headroom for a 2nd card and the 1000AXi iirc is not at the same level of specs, so 850 or 1200 was my choice, and i dont regret the 1200 decision.

 

 

and NO, with 800Watts PSU I would not be able to game with that rig if both 980s were oc'ed and i7 at 4.8.... not even booting maybe as most draw full juice when initialized and that would be more than 800, and you can fuse the OC into the Bios of CPU and GPU... and draw lots of amperes when you hit the button.

 

The last thing you want to do while in an OC session is to use a PSU that runs on the edge of its capabilities, sorry, a 50% headroom is plenty, a 30% needed, 20% close to not working and at the tip of failing will also probably ruin your components as you wont have good signals anymore, causing exessive heat in the curcuits that wouldnt be there if the PSU was more stable. Thats's what stands in most "how-to-OC" I have ever read.

 

my draw "while" gaming ( depends on game as well ) is anywhere between 500 and 550W. Some games use more cores and cause a higher load on the cpu, BF4 draws more than DCS does for example afaict.

 

 

 

low noise is utmost important, I would NOT like to have everything quiet but the PSU whining at 80% load and a squeeking fan, that would have killed the whole idea of very fast performance at very very low or no dB at all...and it works !

 

Bit

Edited September 23, 2015 by BitMaster