estimating power consumption underclocked/undervolt c2duo

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dan
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estimating power consumption underclocked/undervolt c2duo

Post by dan » Sun Dec 11, 2011 10:53 am

Hello,
I have 1 pc with a gigabyte motherboard and a 3ghz wolfdale c2d.

I underclocked it via bios to 1.6ghz by changing multiplier and FSB to 1.6ghz

I was able to undervolt via bios from 1.15volts to 0.85 volts.

What is the power consumption of my pc? 3ghz wolfdale has TDP of 65 watts.

Can I compare it with this?

SU9600

Like the SU9600 my cpu has 3mb cache, 800mhz FSB. It is also an c2duo.

unlike the SU9600 it has 0.85 volts not 1.050 volts.

SU9600 is listed as 10 watts TDP.

http://ark.intel.com/products/37264/Int ... MHz-FSB%29

Intel® Core™2 Duo processor SU9600
(3M Cache, 1.60 GHz, 800 MHz, FSB)

SPECIFICATIONS
All EssentialsPackage SpecificationsAdvanced Technologies
COMPATIBLE PRODUCTS
BLOCK DIAGRAMS
ORDERING / SSPECS / STEPPINGS

Specifications
Essentials
Status
Launched
Launch Date
Q1'09
Processor Number
SU9600
# of Cores
2
# of Threads
2
Clock Speed
1.6 GHz
L2 Cache
3 MB
Bus/Core Ratio
8
FSB Speed
800 MHz
FSB Parity
No
Instruction Set
64-bit
Embedded Options Available
No
Supplemental SKU
No
Lithography
45 nm
Max TDP
10 W
VID Voltage Range
1.050V-1.150V
Recommended Customer Price
$289

Arbutus
Posts: 234
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Location: Calgary, Alberta, Canada

Re: estimating power consumption underclocked/undervolt c2du

Post by Arbutus » Sun Dec 11, 2011 3:15 pm

dan wrote:What is the power consumption of my pc?
You'll have to measure that with a current meter perhaps a "KiloWatt", and tell us.
dan wrote:Can I compare it with this? SU9600
No. They are built with a different process.

CA_Steve
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Re: estimating power consumption underclocked/undervolt c2du

Post by CA_Steve » Sun Dec 11, 2011 5:03 pm

CPU power is proportional to the voltage squared * frequency.

For grins, lets say your 3GHz Wolfdale actually comes near the rated TDP of 65W under heavy load. Your undervolt and underclock leads to a load power of ~29% of 65W = ~19W.

dan
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Re: estimating power consumption underclocked/undervolt c2du

Post by dan » Sun Dec 11, 2011 6:59 pm

Arbutus wrote:
dan wrote:What is the power consumption of my pc?
You'll have to measure that with a current meter perhaps a "KiloWatt", and tell us.
dan wrote:Can I compare it with this? SU9600
No. They are built with a different process.
both 45nm both 3mb cache

dan
Posts: 1243
Joined: Sun Jan 25, 2004 2:01 am
Contact:

Re: estimating power consumption underclocked/undervolt c2du

Post by dan » Sun Dec 11, 2011 7:00 pm

CA_Steve wrote:CPU power is proportional to the voltage squared * frequency.

For grins, lets say your 3GHz Wolfdale actually comes near the rated TDP of 65W under heavy load. Your undervolt and underclock leads to a load power of ~29% of 65W = ~19W.
but Intel® Core™2 Duo processor SU9600
(3M Cache, 1.60 GHz, 800 MHz, FSB)

is TDP 10 watts at 1.05 volts

my wolfdale is 45nm as above, 3mb cache as above 1.6ghz and 800mhz fsb (original 3ghz and 1066gh fsb) 0.85 volts

CA_Steve
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Re: estimating power consumption underclocked/undervolt c2du

Post by CA_Steve » Sun Dec 11, 2011 7:41 pm

Without knowing what your cpu actually consumes, all I can do is guess based on TDP. If you want certainty, plop down $20 and get a power meter. :D

Arbutus
Posts: 234
Joined: Wed Jun 02, 2010 9:15 pm
Location: Calgary, Alberta, Canada

Re: estimating power consumption underclocked/undervolt c2du

Post by Arbutus » Sun Dec 11, 2011 8:13 pm

CA_Steve wrote:CPU power is proportional to the voltage squared * frequency.

For grins, lets say your 3GHz Wolfdale actually comes near the rated TDP of 65W under heavy load. Your undervolt and underclock leads to a load power of ~29% of 65W = ~19W.
NOPE...the power consumption of a modern desktop CPU is NOT linear to voltage, speed or temperature.

CA_Steve
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Location: St. Louis, MO

Re: estimating power consumption underclocked/undervolt c2du

Post by CA_Steve » Mon Dec 12, 2011 9:47 am

Arbutus wrote:NOPE...the power consumption of a modern desktop CPU is NOT linear to voltage, speed or temperature.
Re-read my post and try again. :D

HFat
Posts: 1753
Joined: Thu Jul 03, 2008 4:27 am
Location: Switzerland

Re: estimating power consumption underclocked/undervolt c2du

Post by HFat » Mon Dec 12, 2011 10:07 am

CPU consumption != PC consumption

PC consumption is what you measure with reliable meters and what matters.

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