How many AMPS should cpu pull?

[Grimmkyu]

I know this is an odd question, but monitoring my HWInfo a hidden value (I guess) of "CPU:" popped up, saying "CPU: 15.938A" and then inexplicably vanished o.O. Looking up how many amps computers draw some have been as high as 47 and some have said 4-6? I'm confused. I use an EVGA SuperNova P2 650w PSU and an Intel i7-6700k processor non-overclocked.  

 

Mainly strange the sensor doesn't exist until randomly, but when it does, it's greyed out and I assume the 15.938 A stand for Amps. I could be wrong?

[Electronics Wizardy]

Depends on load, but max around 80-100 for a high power chip.

[Grimmkyu]

Oh really? I was playing WoW when I saw it pop up so I shouldn't worry bout it? Slightly freaked me out thanks to reading some comments by others suggesting it was only 4-6 and mine was 3-4 times that. Thanks!

[airdeano]

amps=watts/volts

 

sounds like you are getting a mixture of terminology.

 

15.938a=191.256w/12v

 

[Grimmkyu]

Yeah, maybe so. Not as technically versed as some others, haha. I just came here to confirm whether or not that was a normal reading to see.

[vanished]

I know it seems crazy to think about since 100 amps is a lot of current, but that actually is what some CPUs will draw.  Just remember that they're managing to consume 60, 80, or over 100 W at only ~1.2 volts (give or take).  Do the math and the amps number is no longer a mystery

[DXMember]

by specification 6700K should be drawing something around 80 A when not overclocked at stock voltage under torture test

 

X99 chips can draw 200 A easily when watercooled and overclocked

If you go LN2 then the numbers go even crazier:

 

[mariushm]

Don't forget that the CPU works with low voltages, like 0.8v .. 1.3v

The total power used by the cpu is equal to V x I   (voltage times current) , so that number may be high but considering you multiply it with a number that's barely above 1v, you're only looking at around 100-140w tops.

 

The VRM (DC-DC converter) converts 12v coming from the 8 pin EPS connector to that low voltage with an efficiency of about 92..98%,  so if the cpu were to use 120 watts, the power supply would only need to provide 10 amps on the 12v connector, which is nothing for a 450-600w power supply.

[Grimmkyu]

True- My cpu voltage fluctuates between 1.2-1.350 or so. Is that okay then?

[DrMikeNZ]

1 hour ago, DXMember said:

X99 chips can draw 200 A easily when watercooled and overclocked

They can even draw more for a brief final moment when the motherboard ****s up and fries the CPU, as many X99 owners found out.

 

35 minutes ago, Grimmkyu said:

True- My cpu voltage fluctuates between 1.2-1.350 or so. Is that okay then?

I would consider that to be ok. Software monitoring programs frequently have misread issues, which can show odd numbers/variables. Not all motherboards attempt to report amps, and those that do are typically not fast enough to measure an accurate reading anyway.

[mariushm]

Yes, the CPU adjusts the frequency of each core independently and may even put the sleep some cores if there's nothing to do.

At lower frequencies (if all cores are idling or working at lower frequencies), the cpu doesn't need that much voltage so it tells the VRM to feed it with lower voltage, in order to improve efficiency and dissipate less heat. 

 

There are also some Intel processors that have their own DC-DC converter built on the processor "square". The idea is that a motherboard DC-DC converter that converts 12v down to a wide range of small voltages that the cpu would use, like 0.6v... 1.1v will have a lousy efficiency between 90-98% and can't react very fast, it would only change the voltage maybe a few hundred times a second.

Intel made some processors that accept a fixed voltage from the motherboard, like 1.3-1.5v for example and convert this to 0.6-1.1v with lousier efficiency (maybe 80-85%) but the advantage is that the output voltage can be changed much faster,  tens of thousands of times a second, or hundreds of thousands of times a second, and this allows the processor to reduce or increase frequency of each core (and the power consumption) more often, overall making it more power efficient.

The efficiency loss by using that integrated vrm is also offset by the fact that the motherboard can now use a more optimized and cheaper VRM which can be made to have a much higher efficiency all the time (because it outputs a relatively fixed voltage)

 

See http://wccftech.com/intel-haswell-incorporate-integrated-voltage-regulator-320-phases-onboard-chips/

 if you're curious about VRMs integrated into processors (motherboards use VRMs with 6-8 phases running at 0.2-0.5 Mhz, while the cpu vrm has up to 320 phases and runs at up to 140 Mhz)

 

And PS:  Aida64 is quite good at reporting CPU information and lots of things. For example, the Sensors section lists CPU usage of each core of my cpu along with the instantaneous power consumption of my cpu, which at the moment is around 39 watts - and it's refreshed every few seconds automatically. (fx8320 , just PC idling, watching a movie on second monitor)

 

 

The Overclock section also reports the instant voltage of the processor and the frequency of one of the cores and detailed information about memory and if it's overclocked or not and so on.

 

With an AMD cpu, if you want detailed info about frequency and voltage of each core, AMD Overdrive used to show that. I'm not aware of a tool that would do that for Intel processors.