What am I missing?

fate0311

Suspended
Original poster
Dec 31, 2015
548
419
With line power under-volting an appliance would prematurely kill it. You would also generate higher current due to the lower volts which would generate more heat.

But you guys friggin lose me when you talk about under voting computers to generate less heat. This goes against everything I was taught.

Someone fix me please.
 

maflynn

Moderator
Staff member
May 3, 2009
63,863
30,387
Boston
With line power under-volting an appliance would prematurely kill it
That's because you would damage the motor and other components that are mechanical in nature.

But you guys friggin lose me when you talk about under voting computers to generate less heat. This goes against everything I was taught.
Check out this link
https://www.reddit.com/r/buildapc/comments/93r2lb/can_someone_explain_undervoltingoverclocking_for/
http://forum.notebookreview.com/threads/the-undervolting-guide.235824/
Undervolting is a process which reduces the excess "voltage" given to the CPU using a software. This is widely used as a cooling solution and in my opinion more effective than any other cooling solution available (thermal paste, cooling pad, etc) at NO cost. Results can vary from 5c up to 30c drop in temperature, most will achieve an average of 10c.
The CPU can run on lower voltage without damage, lower voltage means less heat which means its more likely to run w/o throttling or keep running at peak performance. We're only talking about a difference of millivolts, not a huge swing in voltage.
 

Thysanoptera

macrumors 6502a
Jun 12, 2018
722
723
Pittsburgh, PA
Someone fix me please.
In CPU you need voltage to switch transistor gates and generate some minimum current flow. Anything above it is not useful and just creates silicon based space heater. The voltage supplied to CPU is set higher than absolute minimum required in order to have some safety margin - to assure that the CPU will work at all, but you can reduce it. Apple reduced the voltage on the 8 cores MBP compared to 8th gen.
 
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jerryk

macrumors 601
Nov 3, 2011
4,870
2,412
SF Bay Area
You are talking about running the voltage below the power requirements for an appliance to run it's components like compressors, cooling fans, etc. These components do slow down when you undervolt, the do not work On a CPU under-volting drops it down to the lower limits of junctions in the chips, not below.