CPU constant voltage?

Aaron9546

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If you have your voltage set at 1.225 for example then your cpu is getting a constant voltage of 1.225v all the time can this degrade your chip over time? Also is there any way to make it idle at lower voltage in the bios?
 

utroz

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Depends on the CPU.. I have old cpu's that run at 5V, 3.3V, 2.5V, 2.0V, ect at constant voltage. Even Intel's Skylake and Broadwell which are 14nm can handle 1.225V constant no problem.. Most modern cpu's have dynamic scaling so at idle they run at low MHZ and low volts but at load they run at higher Mhz and higher volts.. You can change the voltage settings on some depending on the BIOS, and sometimes with software as well.. If you take a modern cpu and overvolt it by a large amount it will degrade or fry the cpu (look into LN2 overclocking) for modern intel 1.4V is max safe, and for AMD 1.5V-1.45V depending on the exact cpu..
 

WVMountie07

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Yes, you can lower voltage in bios, but this can decrease stability when the CPU is under load. at 1.225 you shouldn't have any issues. beginning at 1.5 is where (in my opinion) constant load can be damaging over time.
 

Aaron9546

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CPU is 22nm I think i7 4770k

I've just reduced it to 1.195v seems to be stable so running a cpu like that at a constant voltage of 1.200 for example wouldn't damage it at all over time? I was hoping to keep this cpu for 2 years ish
 
If it is running at constant voltage, then you have had to have made a selection in the BIOS telling it to do so, and thereby disabling all power saving features And yes, the life of any electronic component is generally dependent on four things:

1. How long it has been running.
2. How many thermal cycles (on / off) it has experienced
3. What temps it runs at
4. Environment (temperature/ humidity / vibration)

The insulating value of the silicon between circuit traces diminishes according to each of the above to various extents, tho 3 is likely the one you have the most control over. As there is no gain associated with constant voltage in computer usage other than perhaps getting you a higher validated OC to post on the internet.

I am comfy with peak instantaneous voltages of 1.5 (an Intel Haswell CPU seeing 1.375 volts max for example will see a bump of up to 0.13 when AVX instructions are present) but that's only under stress testing.... typical workstation and gaming activities will have it far less and I certainly want it powering down to 0.8 Ghz (0.7 volts) when it's just sitting there doing nothing. More voltage means more heat (and more likelihood of crosstalk between circuit traces) and that will reduce the life of the CPU. In the case of a reduction from 10 years to 5 years, ya might not care.... but 24/7 at constant OC stable voltages is something few outside of the competitive overclocking arena will undertake.


CPU is 22nm I think i7 4770k

I've just reduced it to 1.195v seems to be stable so running a cpu like that at a constant voltage of 1.200 for example wouldn't damage it at all over time? I was hoping to keep this cpu for 2 years ish
At that speed / voltage there is no reason to fix a CPU at any voltage....Auto setting is recommended. Why would you not want it dropping below 1 volt when power is not needed ?
 

Aaron9546

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Lol didn't mean to set this as the answer I set it at 1.2v because it's overclocked from 3.5 to 4.4 and auto makes the cpu go hotter while playing games then manually setting it to 1.2v does
 

utroz

Splendid
It sounds like the OP is trying to undervolt his cpu. Some motherboards have the option to use an voltage off set so you can make it run at less voltage in all P states. Without full system specs we are really just guessing at to what settings are available to you.. (then I saw the post above)

Ok so it is overclocked an manually locked at 4.4 2 1.2V You should still be able to have speed step enabled so it will only run at 4.4Ghz 1.2V at load..
 

Aaron9546

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The motherboard is a Z87-PRO they have two settings of voltage offset and an adaptive mode
 

utroz

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It may be called something else, it is a powersaving feature that allows the cpu to run slow at idle and fast under load. Also look for c-states to be enabled as well.
 

utroz

Splendid
So did some looking and here is what Asus says about adaptive voltage. I think the reason your cpu is stuck at full speed and 1.2v all the time is that you are using manul voltage which locks the cpu at that speed and voltage. If you use adaptive or off set you should be able to have your cpu slow down and save lots of power at idle.. Google your motherboard and read up on the bios settings...
https://rog.asus.com/forum/showthread.php?33886-Need-some-clarification-on-how-to-use-adaptive-voltage
 
Well not really.... the 4770k already had a boost clock of 3.9 GHz outta the box... the 4790k has 4.0 GHz.

I found the Auto setting to overcompensate and there is a very logical reason why..... those voltage values that the MoBo supplies are set based up in house testing and will work for 95% of the CPUs out there. So if you have a CPU that is better than 50% of the CPUs out there, it's over compensating.

But rater than force a constant voltage, you want to set a max voltage. I also assume that you have changed only the default CPU multiplier, not the cache multiplier....which Asus recommends for maximum performance be set to no more than 3 below CPU multiplier. With Asus, you set max voltage via "Additional" voltage settings meaning the additional voltage gets applied only when needed. On Asus, you;d do the following for 4.4 Ghz and default cache speed (2.9 GHz)

AI Overclock Tuner = Auto
1-Core Ratio Limit = 44 (all others should automatically change with Sync all cores selected above)
Max. CPU Cache Ratio = Auto
Min. CPU Cache Ratio = Auto
Fully Manual Mode = Disabled
Core Voltage = Adaptive
Additional Turbo Mode CPU Core Voltage = 1.200
Core Cache Voltage = Adaptive
Additional Turbo Mode CPU Cache Voltage = Auto
Eventual CPU Input Voltage = 1.90
DRAM Voltage = Auto

This way you will see 1.2 volts when needed, 0.7 volts when not
 

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