Ryzen chips, silly question

Feb 4, 2009
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#1
I’m thinking of a 2700x system. I know the new chips will be arriving soon but it’s unlikely I can wait.

I feel silly asking this.
Do Ryzen chips down clock/use less energy when they do not require the extra performance.
If I’m using a 2700x just web browsing or doing some web based work stuff do they use less than their 105 watts?
Can you “down” clock them manually?
 

whm1974

Diamond Member
Jul 24, 2016
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#2
I’m thinking of a 2700x system. I know the new chips will be arriving soon but it’s unlikely I can wait.

I feel silly asking this.
Do Ryzen chips down clock/use less energy when they do not require the extra performance.
If I’m using a 2700x just web browsing or doing some web based work stuff do they use less than their 105 watts?
Can you “down” clock them manually?
Do you mean lowering the clock speeds when not needed? Well yes modern x86/x64-64 CPUs been doing that for a long time now.

Manually, depending on the Motherboard Firmware and software, then Yes.
 
Feb 4, 2009
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#3
Do you mean lowering the clock speeds when not needed? Well yes modern x86/x64-64 CPUs been doing that for a long time now.

Manually, depending on the Motherboard Firmware and software, then Yes.
Okay I suspected that. So if it’s just running light duty stuff it won’t use its full wattage, maybe like 60-80 watts give or take.
 

Tuna-Fish

Senior member
Mar 4, 2011
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#4
Okay I suspected that. So if it’s just running light duty stuff it won’t use its full wattage, maybe like 60-80 watts give or take.
Much less than that when the load is slow. For examples, look at this. Light desktop duty is somewhere between "off" and "cad", so ~13W-30W. Even used by running a frame-uncapped game uses only ~half of the TDP, they needed a torture test specifically designed to stress the CPU for that.
 
Feb 4, 2009
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#5
Much less than that when the load is slow. For examples, look at this. Light desktop duty is somewhere between "off" and "cad", so ~13W-30W. Even used by running a frame-uncapped game uses only ~half of the TDP, they needed a torture test specifically designed to stress the CPU for that.
Huge find thank you for posting it

Long term plan for the machine may be to use it as a game server for some friends but I certainly don’t want a 105 watt machine running all the time. Thats why I was wondering if you could under volt it to run slower.
That use is only a maybe use. I’ll likely be too lazy to bother setting it up.
 
Mar 10, 2004
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#6
Okay I suspected that. So if it’s just running light duty stuff it won’t use its full wattage, maybe like 60-80 watts give or take.
Yes, modern CPUs try to use as little power as necessary, unless they are set up otherwise in BIOS, or if Windows is set to High Performance.
 

whm1974

Diamond Member
Jul 24, 2016
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#7
Yes, modern CPUs try to use as little power as necessary, unless they are set up otherwise in BIOS, or if Windows is set to High Performance.
Even then, wouldn't they still down clock when idle?
 
Mar 10, 2004
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#8
Huge find thank you for posting it

Long term plan for the machine may be to use it as a game server for some friends but I certainly don’t want a 105 watt machine running all the time. Thats why I was wondering if you could under volt it to run slower.
That use is only a maybe use. I’ll likely be too lazy to bother setting it up.
My 4790K chip uses under 15 watts at idle, for example.

I am using an i5-3330 right now and HWinfo reports 10 watts for the CPU.
 
Mar 10, 2004
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#9
Even then, wouldn't they still down clock when idle?
No.

If you set the CPU to high performance, the clocks stay high as far as I have ever seen.
Power still fluctuates because of a lack of load, though.
 
Aug 25, 2001
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#10
Yes, they have very sophisticated power-management, and they do down-clock (or clock-throttle) at idle.
 

Topweasel

Diamond Member
Oct 19, 2000
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#11
Even then, wouldn't they still down clock when idle?
It should but it basically waits out activity a long time before downclocking for increased responsiveness. Basically absolutely nothing can be going on for it to down clock and generally doesn't play with intermediary steps.
 

Markfw

CPU Moderator, VC&G Moderator, Elite Member
Super Moderator
May 16, 2002
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#12
It should but it basically waits out activity a long time before downclocking for increased responsiveness. Basically absolutely nothing can be going on for it to down clock and generally doesn't play with intermediary steps.
Do you have a Ryzen ? My threadrippers go down quickly when not in use (which is only right after OS, since I thrash them all day every day)
 

Topweasel

Diamond Member
Oct 19, 2000
4,767
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#13
Yeah I have a Ryzan but I mostly use Ryzen Balanced. But high performance has always tried to hold clocks longer for reponsiveness. Longer doesn't mean forever, hell maybe not even really measurable because you know milliseconds and such. But it's less likely to try to figure out what speed it can run at it's either doing something and runs at ~max or down clocking to idle speeds.
 

Insert_Nickname

Diamond Member
May 6, 2012
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#14
Don't worry. Ryzen has some of the most sophisticated power management features anywhere. It won't use any more power then required.

Just leave it to the CPU itself. It'll handle that itself. Frequency is lowered automatically, cores power gated when not in use etc.

If you overclock a Ryzen, most power management goes out the window though. There is little reason to OC a 2700X however, because you are unlikely to get a better result then the CPU can manage itself.
 
May 11, 2008
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#15
Okay I suspected that. So if it’s just running light duty stuff it won’t use its full wattage, maybe like 60-80 watts give or take.
To give some indication : My complete ryzen system in my signature draws about 53 watts from the 230V socket when idle.
Add another 2 12V fans that are not in the signature .
And of course, the PSU is providing about 10% of its available peak power.
So the efficiency of the psu is much lower than when loaded to about 70% for example.
(A proper psu is always designed to have maximum efficiency during full load or being near full load because then the electrical losses are the greatest. So, there is more to gain to have the highest efficiency at those times. When the load is low, proportionally even the though the efficiency is a bit lower, the electrical losses are lower because there is less output power provided.)
 
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Mar 10, 2004
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#16
Do you have a Ryzen ? My threadrippers go down quickly when not in use (which is only right after OS, since I thrash them all day every day)
Do they downclock quickly with Windows set to High Performance? That's the question.
 

Insert_Nickname

Diamond Member
May 6, 2012
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#17
(A proper psu is always designed to have maximum efficiency during full load or being near full load because then the electrical losses are the greatest. So, there is more to gain to have the highest efficiency at those times. When the load is low, proportionally even the though the efficiency is a bit lower, the electrical losses are lower because there is less output power provided.)
I agree the starting point for a power efficient system should always be the PSU.

Most PC PSU are actually designed to be most efficient at half (40-60%) load. When you get below 10% efficiency drops like a stone. But at such low loads, it doesn't matter too much unless you have a completely overkill PSU.

Ideally, your systems full load should be ~50% of your PSUs rating. Getting it right usually involves some guesstimates. As an example, my own Ryzen 1700, Crosshair VI and GTX1060 system pulls 42W at idle and somewhere around 230W at full CPU+GPU load. This is with a Seasonic 660XP2.

Do they downclock quickly with Windows set to High Performance? That's the question.
Ryzen can manage power without OS intervention. Setting a Ryzen to high performance mode just disable OS core parking, but the chip itself still parks unused cores, and downclock.
 
May 11, 2008
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#18
I agree the starting point for a power efficient system should always be the PSU.

Most PC PSU are actually designed to be most efficient at half (40-60%) load.
I am not sure about the numbers. Although it makes sense to provide higher efficiency with increasing power output for a PSU.

When you get below 10% efficiency drops like a stone.
But at such low loads, it doesn't matter too much unless you have a completely overkill PSU.
Indeed.

Ideally, your systems full load should be ~50% of your PSUs rating. Getting it right usually involves some guesstimates. As an example, my own Ryzen 1700, Crosshair VI and GTX1060 system pulls 42W at idle and somewhere around 230W at full CPU+GPU load. This is with a Seasonic 660XP2.
SInce the load is variable, it is difficult but yes aiming for around 50% is a good thing. I bought my psu for a similar targeted power envelope.
But it all depends on the type of application. When using the DOOM game with the highly efficient IDtech 6 engine, i notice quite the difference with my ryzen system.

Everything set to max, 1920x1080@60Hz :
With Vsync on, the power consumption at the 230V inlet is ~185watts.
With Vsync off, the power consumption at the 230V inlet increases to ~289watts.
 

hasu

Senior member
Apr 5, 2001
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#19
Much less than that when the load is slow. For examples, look at this. Light desktop duty is somewhere between "off" and "cad", so ~13W-30W. Even used by running a frame-uncapped game uses only ~half of the TDP, they needed a torture test specifically designed to stress the CPU for that.
Numbers in that chart look much lower than anything I ever noticed using a kill-a-watt (or similar) from the wall. In order to run your desktop computer in Windows, you need a minimum setup with a hard drive or ssd, even if you remove keyboard and mouse.

How is TH measuring the "Package Power Consumption"?
 
Mar 10, 2004
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#20
Numbers in that chart look much lower than anything I ever noticed using a kill-a-watt (or similar) from the wall. In order to run your desktop computer in Windows, you need a minimum setup with a hard drive or ssd, even if you remove keyboard and mouse.

How is TH measuring the "Package Power Consumption"?
Tom's is measuring chip power, rather than system power. So there's no mystery about the low numbers.

Power Consumption Measurement
Contact-free DC Measurement at PCIe Slot (Using a Riser Card)
Contact-free DC Measurement at External Auxiliary Power Supply Cable
Direct Voltage Measurement at Power Supply
2x Rohde & Schwarz HMO 3054, 500 MHz Digital Multi-Channel Oscilloscope with Storage Function
4x Rohde & Schwarz HZO50 Current Probe (1mA - 30A, 100 kHz, DC)
4x Rohde & Schwarz HZ355 (10:1 Probes, 500 MHz)
1x Rohde & Schwarz HMC 8012 Digital Multimeter with Storage Function
 
Aug 25, 2001
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#21
Do they downclock quickly with Windows set to High Performance? That's the question.
Honestly? That's going to be hard to measure. They use clock-gating internally. Which means, the clock on the core (s) internally may be stopped for a minute period, but the external clock being supplied to the CPU is still running at full speed, therefore, software tools like CPU-Z will still report max clocks running.
 
Feb 4, 2009
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#22
Does anyone outside of AT ever put windows 10 in performance mode and leave it that way?
 

chrisjames61

Senior member
Dec 31, 2013
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#23
Does anyone outside of AT ever put windows 10 in performance mode and leave it that way?

Many people who are overclockers or gamers and the likes will set Windows to High Performance Plan. I think you are overthinking this whole thing. Just set your power plan to Balanced and your bios to Optimized Defaults and forget about it. The rig will sip power when not under heavy load.
 

AnnoyedGrunt

Senior member
Jan 31, 2004
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#24
I have a 2700X and run under the "balanced" plan with the "minimum processor state" at its default value of 5%.

Under that mode, the CPU will idle around 2.13 GHz according to the Windows 10 Task Manager (2200 MHz according to Ryzen Master). In this state, HWInfo has the CPU "Package Power" @ ~18 W with the "Cores" @ ~1.6 W.

If I run under the "High Performance" plan the "minimum processor state" is set to 100% and the CPU idles @ ~3.7 GHz (fluctuating around 4075 MHz according to Ryzen Master). In this state, HWInfo has the CPU "Package Power" @ ~25 W with the "Cores" @ ~4.5 W.

In both cases, when a load is placed on the CPU (for example using the Ryzen Master Test), the Frequency goes to 4 Ghz, Package Power to ~96W and Cores to ~93 W.

So, even under the High Performance plan you do save lots of power when idling compared to when under load. However, since I don't notice a performance difference between the "Balanced" or "High Performance" plans, and since it seems like you save a couple watts with the balanced plan during idle, I figure that it makes sense to run in that mode for a bit more power savings.

I haven't measured total system power at the wall, but I did just order a Kill-A-Watt power strip, so next week I should have a better idea of total draw.

-AG
 
Apr 16, 2014
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#25
you folks are lucky... my PC (48 core quad opty) idles at something like 390w... then again i am running high performance. It does nicely for heating the room though.
 

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