mersenneforum.org  

Go Back   mersenneforum.org > Fun Stuff > Lounge

Reply
 
Thread Tools
Old 2013-12-12, 20:54   #1
petrw1
1976 Toyota Corona years forever!
 
petrw1's Avatar
 
"Wayne"
Nov 2006
Saskatchewan, Canada

17×263 Posts
Default How much power am I really using?

I know what I have for a power supply in each system.
But if they all were at capacity my power bill for PCs alone would be the whole bill.
Does anyone have a sense for how much power a PC typically daws?
For example an i5-750 or an i5-3570, both OC'd 20%. Fan, CPU and RAM probably non stop but Monitor is almost always off, and hard drive too. No GPU.

Or is there a device I can get to measure it?

Thx
petrw1 is offline   Reply With Quote
Old 2013-12-12, 20:56   #2
kracker
ἀβουλία
 
kracker's Avatar
 
"Mr. Meeseeks"
Jan 2012
California, USA

32·241 Posts
Default

Quote:
Originally Posted by petrw1 View Post
I know what I have for a power supply in each system.
But if they all were at capacity my power bill for PCs alone would be the whole bill.
Does anyone have a sense for how much power a PC typically daws?
For example an i5-750 or an i5-3570, both OC'd 20%. Fan, CPU and RAM probably non stop but Monitor is almost always off, and hard drive too. No GPU.

Or is there a device I can get to measure it?

Thx
Kill-A-Watt for sure!
kracker is offline   Reply With Quote
Old 2013-12-12, 21:04   #3
chalsall
If I May
 
chalsall's Avatar
 
"Chris Halsall"
Sep 2002
Barbados

3·55 Posts
Default

Quote:
Originally Posted by kracker View Post
Kill-A-Watt for sure!
I agree.

You cannot measure the draw on a DC (direct current) feed without "being in the circuit".

An AC (alternating current) feed *can* be measured without being in the circuit, so long as you know the frequency and the voltage being used.

This is grade-school physics.
chalsall is offline   Reply With Quote
Old 2013-12-12, 21:14   #4
sdbardwick
 
sdbardwick's Avatar
 
Aug 2002
North San Diego County

23×5×17 Posts
Default

Quote:
Originally Posted by chalsall View Post
You cannot measure the draw on a DC (direct current) feed without "being in the circuit".
Hall effect sensors would disagree.
sdbardwick is offline   Reply With Quote
Old 2013-12-12, 21:27   #5
chalsall
If I May
 
chalsall's Avatar
 
"Chris Halsall"
Sep 2002
Barbados

3·55 Posts
Default

Quote:
Originally Posted by sdbardwick View Post
Hall effect sensors would disagree.
As always, I'm very happy to be corrected.

I was arguing from the perspective of the instrumentation most of us have available to us. Perhaps that was short-sighted.

A DC meter can only measure DC load when "in circuit".

Most electricians carry around with them a device which can measure the number of amps being carried through a single wire carrying AC -- importantly without having to break the wire, but only when encircling a single current carrying wire -- when the device encircles the bundled wires it measures zero (as it should).

Perhaps you could let us all know what hall effect sensors are available retail? I would sincerely be interested in knowing.
chalsall is offline   Reply With Quote
Old 2013-12-12, 21:44   #6
Mark Rose
 
Mark Rose's Avatar
 
"/X\(‘-‘)/X\"
Jan 2013

2,917 Posts
Default

Quote:
Originally Posted by petrw1 View Post
I know what I have for a power supply in each system.
But if they all were at capacity my power bill for PCs alone would be the whole bill.
Does anyone have a sense for how much power a PC typically daws?
For example an i5-750 or an i5-3570, both OC'd 20%. Fan, CPU and RAM probably non stop but Monitor is almost always off, and hard drive too. No GPU.

Or is there a device I can get to measure it?

Thx
For a ballpark answer, take the CPU max TDP and add 10-20 watts for motherboard, RAM, fans, and PS inefficiency.

Last fiddled with by Mark Rose on 2013-12-12 at 21:49
Mark Rose is offline   Reply With Quote
Old 2013-12-12, 21:48   #7
chalsall
If I May
 
chalsall's Avatar
 
"Chris Halsall"
Sep 2002
Barbados

3×55 Posts
Default

Quote:
Originally Posted by Mark Rose View Post
For a ballpark answer, take the CPU max TDP and add 20-30 watts for motherboard, RAM, fans, and PS inefficiency.
That's not a measurement. It's an estimate.

A very important difference.
chalsall is offline   Reply With Quote
Old 2013-12-12, 21:56   #8
fivemack
(loop (#_fork))
 
fivemack's Avatar
 
Feb 2006
Cambridge, England

23×797 Posts
Default

Quote:
Originally Posted by petrw1 View Post
I know what I have for a power supply in each system.
But if they all were at capacity my power bill for PCs alone would be the whole bill.
Does anyone have a sense for how much power a PC typically daws?
For example an i5-750 or an i5-3570, both OC'd 20%. Fan, CPU and RAM probably non stop but Monitor is almost always off, and hard drive too. No GPU.

Or is there a device I can get to measure it?

Thx
You can get a variety of in-line electricity meters; I own six. The i7/4770K box is 25W idle 90W flat-out, the Avoton is 20W idle 35W flat-out, the i7/4930K is 100W idle 160W flat-out 220W flat-out-with-GPGPU-on-top. The 48-core Opteron 6128 is about 300W idle and 550W flat-out.
fivemack is offline   Reply With Quote
Old 2013-12-12, 22:07   #9
chalsall
If I May
 
chalsall's Avatar
 
"Chris Halsall"
Sep 2002
Barbados

3×55 Posts
Default

Quote:
Originally Posted by fivemack View Post
You can get a variety of in-line electricity meters; I own six. The i7/4770K box is 25W idle 90W flat-out, the Avoton is 20W idle 35W flat-out, the i7/4930K is 100W idle 160W flat-out 220W flat-out-with-GPGPU-on-top. The 48-core Opteron 6128 is about 300W idle and 550W flat-out.
Please correct me if I'm wrong, but this is "in the CPUs".

Measuring the total power draw on the DC rails is a little tougher....
chalsall is offline   Reply With Quote
Old 2013-12-12, 22:09   #10
sdbardwick
 
sdbardwick's Avatar
 
Aug 2002
North San Diego County

23×5×17 Posts
Default

Fluke and other makers have a bunch of clip-on probes/meters. If they measure DC current via clip-on probe, then they are using Hall effect sensors.

An (expensive for casual hobbyist) example is the Fluke i410, which is just a probe and used along with your multimeter.

Of course there are cheaper units, like this one via Amazon.


Hall effect sensors are often used with magnets as a contact-less substitute for magnet/reed switch combinations (as the mechanical reed switch is limited in lifetime and response rate).
sdbardwick is offline   Reply With Quote
Old 2013-12-12, 22:13   #11
petrw1
1976 Toyota Corona years forever!
 
petrw1's Avatar
 
"Wayne"
Nov 2006
Saskatchewan, Canada

17×263 Posts
Default

Quote:
Originally Posted by fivemack View Post
You can get a variety of in-line electricity meters; I own six. The i7/4770K box is 25W idle 90W flat-out, the Avoton is 20W idle 35W flat-out, the i7/4930K is 100W idle 160W flat-out 220W flat-out-with-GPGPU-on-top. The 48-core Opteron 6128 is about 300W idle and 550W flat-out.
Thanks all but I think this is what I want....an inline meter.....and a few 48 cores :)
petrw1 is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
More Power!!!! petrw1 Teams 10 2019-10-15 17:36
TDP as power used? CRGreathouse Hardware 9 2016-02-06 18:46
Power??? JohnFullspeed Programming 5 2011-08-30 16:28
Power 2 JohnFullspeed Miscellaneous Math 45 2011-07-10 20:13
IBM Power 6 Unregistered Information & Answers 7 2008-08-30 14:36

All times are UTC. The time now is 14:13.

Thu Dec 3 14:13:12 UTC 2020 up 10:24, 0 users, load averages: 1.37, 1.46, 1.40

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.