How is my CM650i able to draw over 700W?

[LTG.]

Hey guys

 

I have recently upgraded to a 3080. I read some around found that using a good quality 650W would be sufficient to achieve stablization. 

 

I have been playing at 4k 144fps on rainbow 6 for good 30 minutes for a test, and it caused no issue!

 

I looked at my hwinfo log and realised that it reached a total of 721W sum power draw... What is heck is going on, my PSU is clearly a 650W max. Is this dangerous or is it a sensor bug? What do you guys think?

 

Cheers

Alec

 

 

 

[RollinLower]

software powerdraw readings are known to be faulty sometimes. if you really want accurate powerdraw you could get something like a kill-a-watt or maybe just hook up a current clamp and do some math.

[boggy77]

two things: software power draw is not always reliable and the 650w is not really max, it's min. so a good quality 650w unit might be able to supply 700w

[CommanderAlex]

Software monitoring can always incorrectly measure sensor readings and can be happening here. As suggested by @RollinLower, the use of a Kill-a-Watt Meter (connects between the PSU cable and wall outlet) to measure the power draw there will be higher than the power output by the PSU, due to inefficiencies such as converting from AC to DC (not 100% efficient). Power supplies can deliver more power than they are rated for for short bursts if and only if the power supply is built with quality in mind. Your PSU will be pretty efficient at converting V_AC to V_DC since you seem to be using 230V_AC power (outside of North America-which uses 120V_AC/240V_AC). 

 

I'd suggest to read this article from the forums here, especially the 4th point down on the list. 

 

[Spotty]

CM650i? I'm assuming you meant the Corsair RM650i?

The RMi series power supplies have digital monitoring for power consumption which you can view in iCue. It will show how much power the power supply is providing to the system, should be more reliable than software readings as it's actually receiving information from the power supply.

 

The 650W rating is what it's rated for continuous operation at 50°C. It won't switch off at 651W output, it can handle peaks more than that - though I wouldn't recommend running a PSU above what it is rated for as you are exceeding what it is rated for and that along with the additional heat it can reduce the lifespan of the PSU, and if you do draw too much power you will experience issues with it shutting down. If you're pulling too much power from it the PSU will switch off when OCP or OPP is tripped, with the latter being I believe somewhere around 750-800W total output for the RM650i.

Edited March 5, 2021 by Spotty

[D13H4RD]

The wattage rating for PSUs deemed good isn't actually the maximum that unit can supply. These are rated in continuous power under certain conditions as Spotty mentioned.

 

It can definitely supply quite a bit more, but it's used more to account for potential spikes. Don't exceed the rated wattage regardless.

[Dedayog]

As I have been corrected by those that know these things, a 650w PSU can't push over 700w like that.  So it's obviously a software issue.

 

I had too thought that a 650w PSU would be able to handle peaking power draws upwards of 10-20% of it's max but maybe not.

[Juular]

This is not exactly a case of incorrect software readings as these readings (of digitally controlled Corsair PSU) are straight from the PSU's protections monitoring system. They are correct (more or less), yes, you're reading it right. It's just that all (good) PSUs have some headroom in power output to accommodate for power draw spikes, usually about 20-30%. So a 650W PSU will be able to output about 700-900W before it trips over-current/power protection. It's obviously not recommended to overpower PSU routinely but in this case it's a very high transient power draw GPU and these peaks are less that millisecond long, if it works without tripping protections then it's fine, but with some of the other PSUs 650W wouldn't have worked and you would've needed 750/850W one.

[Guest]

4 hours ago, LTG. said:

Hey guys

 

I have recently upgraded to a 3080. I read some around found that using a good quality 650W would be sufficient to achieve stablization. 

 

I have been playing at 4k 144fps on rainbow 6 for good 30 minutes for a test, and it caused no issue!

 

I looked at my hwinfo log and realised that it reached a total of 721W sum power draw... What is heck is going on, my PSU is clearly a 650W max. Is this dangerous or is it a sensor bug? What do you guys think?

 

Cheers

Alec

 

 

 

So... it doesn't look like you're using Link/iCUE.  So I don't know what "PSU Power (sum) actually means.  Can you do the logging in iCUE And make sure you're logging the DC OUTPUT and not the AC INPUT.  Because AC input is going to be higher (obviously).