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Undervolting CPU’s

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Undervolting is done to optimize temperatures and power draw. Think of it as overclocking, but instead of optimizing for performance, the goal is optimizing for efficiency.

 

It is most effective for laptops where thermal throttling is more common and in mining operations where reduced power draw increases profits. In a desktop platform with a locked CPU, there really isn't a good reason to undervolt, since you are not likely to run into thermal issues, and you would be introducing potential instability with no real tangible benefits.

Hi all!

 

I came across a  thing called undervolting. Which I read that decreasing the voltage of your CPU can help reduce temps. I was curious is there any specific reason why you shouldn’t do it or should? The reason that I am asking is because I have been having some issues with CPU temps and was wondering if this would help. FYI I know next to none about undervolting, so any info or advice would be great.

 

My CPU: I7-8700 

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Undervolting is done to optimize temperatures and power draw. Think of it as overclocking, but instead of optimizing for performance, the goal is optimizing for efficiency.

 

It is most effective for laptops where thermal throttling is more common and in mining operations where reduced power draw increases profits. In a desktop platform with a locked CPU, there really isn't a good reason to undervolt, since you are not likely to run into thermal issues, and you would be introducing potential instability with no real tangible benefits.

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2 minutes ago, badreg said:

Undervolting is done to optimize temperatures and power draw. Think of it as overclocking, but instead of optimizing for performance, the goal is optimizing for efficiency.

Is there any harm in doing It? Also, how hard is it to do?

 

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10 minutes ago, badreg said:

Undervolting is done to optimize temperatures and power draw. Think of it as overclocking, but instead of optimizing for performance, the goal is optimizing for efficiency.

 

It is most effective for laptops where thermal throttling is more common and in mining operations where reduced power draw increases profits. In a desktop platform with a locked CPU, there really isn't a good reason to undervolt, since you are not likely to run into thermal issues, and you would be introducing potential instability with no real tangible benefits.

Thank you for the information and help!

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only 3 reasons not to do it

1. Laziness

2. Very low power draw CPU (200GE for example) in the first place

3. Looking to overclock.

because the only people who don't want lower heat output and higher efficiency are overclockers. If overclocking is squeezing performance out from the safety (by safety I mean the system passing stress test) margins put in by the motherboard makers, undervolting is squeezing efficiency out from the same thing.

 

11 minutes ago, I Josh I said:

Also, how hard is it to do?

On a desktop it's easy because you don't hit power limits. On laptops that's much more difficult because the CPU behaves differently when it runs in full turbo boost and limited turbo boost (PL2 and PL1).

CPU: i7-2600K 4751MHz 1.44V (software) --> 1.47V at the back of the socket Motherboard: Asrock Z77 Extreme4 (BCLK: 103.3MHz) CPU Cooler: Noctua NH-D15 RAM: Adata XPG 2x8GB DDR3 (XMP: 2133MHz 10-11-11-30 CR2, custom: 2203MHz 10-11-10-26 CR1 tRFC:230 tREFI:14000) GPU: Asus GTX 1070 Dual (Super Jetstream vbios, +70(2025-2088MHz)/+400(8.8Gbps)) SSD: Samsung 840 Pro 256GB (main boot drive), Transcend SSD370 128GB PSU: Seasonic X-660 80+ Gold Case: Antec P110 Silent, 5 intakes 1 exhaust Monitor: AOC G2460PF 1080p 144Hz (150Hz max w/ DP, 121Hz max w/ HDMI) TN panel Keyboard: Logitech G610 Orion (Cherry MX Blue) with SteelSeries Apex M260 keycaps Mouse: BenQ Zowie FK1

 

Model: HP Omen 17 17-an110ca CPU: i7-8750H (0.125V core & cache, 50mV SA undervolt) GPU: GTX 1060 6GB Mobile (+80/+450, 1650MHz~1750MHz 0.78V~0.85V) RAM: 8+8GB DDR4-2400 18-17-17-39 2T Storage: HP EX920 1TB PCIe x4 M.2 SSD + Crucial MX500 1TB 2.5" SATA SSD, 128GB Toshiba PCIe x2 M.2 SSD (KBG30ZMV128G) gone cooking externally, 1TB Seagate 7200RPM 2.5" HDD (ST1000LM049-2GH172) left outside Monitor: 1080p 126Hz IPS G-sync

 

Desktop benching:

Cinebench R15 Single thread:168 Multi-thread: 833 

SuperPi (v1.5 from Techpowerup, PI value output) 16K: 0.100s 1M: 8.255s 32M: 7m 45.93s

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Be aware that if temperature or power throttling then undervolting may just end up increasing the clock speed while still consuming the same power, resulting in the same high temps.

 

As for locked chips the Haswell Xeons can reach higher all core turbo by undervolting so the results can vary.

 

Tip: When using a negative offset test for both low/idle clocks and high clocks as it may be possible there's enough voltage for the high end but not the low end.

AWOL

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