Need a psu wizard - psu power draw from the wall

[Jay85]

Specs of system:
i5 9600k @5.1ghz
RTX 3090
2 x D5 pumps
8 fans
4 LED strips

I have a EVGA GQ 750W gold rated psu. From research and reading i know at different loads the psu will have different efficiency ratings. I'm currently reading around 540 while gaming and 600w benchmarking on the kill a watt meter. Now i know this is a reading from the wall and not what the psu is actually using, but if we're talking theoretical 100% load via benchmarking, what is the actual power draw at the psu based on 540w gaming and 600w benchmarking?

I'm asking this cos i've just acquired a i9 9900k and i know im gonna be close to the limit but at the same time due to efficiency ratings and what im reading at the wall isn't what the psu is actually drawing, will it be okay to run like this "short term" while i hunt for a 850w-1000w psu.

The 9900k draws roughly around an extra 80w more than the 9600k at the same clock speed so that puts me around the 640w gaming and 700w benchmarking, again this is at the wall and not at the psu.

I have a feeling i don't need a psu but people always talk about getting a little bigger wattage to be on the safe side. But then being on the safe side doesn't mean you're being efficient.. see my point?

 

[Grimley]

Have a read of this:

https://en.wikipedia.org/wiki/80_Plus#Technical_overview

If I read it right:

Assuming You'd be be drawing 700w from the wall with a 9900K benchmarking, according to this review:

https://www.tomshardware.com/uk/reviews/evga-gq-series-750w-psu,4396-5.html

90% efficency at that load give or take a couple of % = so 10% is waste energy (heat) & what the PSU uses. 630w is what I make it.

Realistically you're not going to be benchmarking a rig 24/7 or gaming either.

On the other hand the older a PSU gets, the less capable it is of sustaining its max output.

My advice is to go with with your gut feeling. My opinion is that it all depends on the PSU's age. Looking at the tier list there are better PSU's out there than the GQ & the rule of thumb on here is to not skimp on the PSU.

 

[Jay85]

Have a read of this:

https://en.wikipedia.org/wiki/80_Plus#Technical_overview

If I read it right:

Assuming You'd be be drawing 700w from the wall with a 9900K benchmarking, according to this review:

https://www.tomshardware.com/uk/reviews/evga-gq-series-750w-psu,4396-5.html

90% efficency at that load give or take a couple of % = so 10% is waste energy (heat) & what the PSU uses. 630w is what I make it.

Realistically you're not going to be benchmarking a rig 24/7 or gaming either.

On the other hand the older a PSU gets, the less capable it is of sustaining its max output.

My advice is to go with with your gut feeling. My opinion is that it all depends on the PSU's age. Looking at the tier list there are better PSU's out there than the GQ & the rule of thumb on here is to not skimp on the PSU.

That's the ball park figure i had in my head but needed it confirming. Basing it on that i think im well within spec and should be okay and like you said im not gaming nor benchmarking all day and definitely not mining.

If we're talking about gaming only then im at a even lower power draw at the psu. The PSU is less than 2 years old and previously spent most of its time powering a SLI 680 with a 3770k and more recently 9600k with a 2080. It's newest hardware has been the rtx 3090 and todays 9900k. I'll see what the watt meter actually says tonight after i've swapped it all out and put a accurate reading here.

Thanks for reading up and confirming Grimley.

 

[EsaT]

Efficiency is around 91-92%
So that's currently about 500W while gaming and 550W benching.

Would myself definitely want 850W as minimum PSU for such power hogging parts.

 

[Jay85]

Efficiency is around 91-92%
So that's currently about 500W while gaming and 550W benching.

Would myself definitely want 850W as minimum PSU for such power hogging parts.

Quick game tonight and im hitting around 580w at the wall, stress tested all core 5.0ghz at 1.3v with llc on high, drops down to 1.26v. Got it stable at the moment but i think i can drop voltage some more.

Weirdly if im doing fft stress tests on prime95 i get something weird going on... the cpu usage drops every few seconds after test 16 to around 50% then goes back up again. Works fine initially but then will drop and continue doing so until i stop it... not sure whats going on there.

Edit: found the issue, it was the vrms hitting 125c! Got a fan over the vrms and adjusted some voltages. Stays under 100c now with no throttling.