Is there a lower bound on power consumption of CPU
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I currently run a old laptop from 2015 with i7-4720HQ as a linux server at home. The TDP of that chip is 47W.
Now, I know that TDP means the chip can't go beyond 47W of power consumption, is there a lower bound to power consumption? i.e. When it's not turned off and maintains a minimum system footprint, is there information about how much energy it would consume at that state? Is there a minimum power required to power the chip and how much would that be.
cpu power-supply
asked Nov 23 at 16:48
Rocky Li
1134
add a comment |
up vote
0
down vote
favorite
I currently run a old laptop from 2015 with i7-4720HQ as a linux server at home. The TDP of that chip is 47W.
Now, I know that TDP means the chip can't go beyond 47W of power consumption, is there a lower bound to power consumption? i.e. When it's not turned off and maintains a minimum system footprint, is there information about how much energy it would consume at that state? Is there a minimum power required to power the chip and how much would that be.
cpu power-supply
asked Nov 23 at 16:48
Rocky Li
1134
Your CPU itself will use virtually no power when using a c-state (ie cpu sleep state) other then 0. Almost all power used in sleep states are used by peripherals and especially RAM [the various sleep states determine what parts of the system are turned off]
– davidgo
Nov 24 at 1:29
1
What do you mean by "not turned off" and "minimum system footprint"? Is it fully on or sleeping? Is the screen being refreshed? Is it accepting mouse/keyboard input? Can we ignore Wake-On-LAN which is not controlled by CPU?
– davidgo
Nov 24 at 18:24
@davidgo say the system is running on background, accepting ssh connections and runs a set of process that keeps the OS alive
– Rocky Li
Nov 24 at 18:26
1
I think it will be almost impossible to find this info - the best I could come up with was a detailed description of of power management for 4th gen mobile CPUs at intel.com/content/www/us/en/processors/core/…. While there is a minimal figure, practically it may make sense to tune the system with power top, set clock speeds to minimum and use a killawatt meter or similar to measure entire system draw. I'm GUESSING a figure of about 8 watts all up.
– davidgo
Nov 24 at 18:45
(also, tdp is not the expected maximum power consumption in real world loads, but not the maximum the CPU can actually use)
– davidgo
Nov 24 at 18:47
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I currently run a old laptop from 2015 with i7-4720HQ as a linux server at home. The TDP of that chip is 47W.
Now, I know that TDP means the chip can't go beyond 47W of power consumption, is there a lower bound to power consumption? i.e. When it's not turned off and maintains a minimum system footprint, is there information about how much energy it would consume at that state? Is there a minimum power required to power the chip and how much would that be.
cpu power-supply
asked Nov 23 at 16:48
Rocky Li
1134
I currently run a old laptop from 2015 with i7-4720HQ as a linux server at home. The TDP of that chip is 47W.
Now, I know that TDP means the chip can't go beyond 47W of power consumption, is there a lower bound to power consumption? i.e. When it's not turned off and maintains a minimum system footprint, is there information about how much energy it would consume at that state? Is there a minimum power required to power the chip and how much would that be.
cpu power-supply
cpu power-supply
asked Nov 23 at 16:48
Rocky Li
1134
asked Nov 23 at 16:48
Rocky Li
1134
asked Nov 23 at 16:48
Rocky Li
1134
asked Nov 23 at 16:48
Rocky Li
1134
asked Nov 23 at 16:48
Rocky Li
1134
1134
Your CPU itself will use virtually no power when using a c-state (ie cpu sleep state) other then 0. Almost all power used in sleep states are used by peripherals and especially RAM [the various sleep states determine what parts of the system are turned off]
– davidgo
Nov 24 at 1:29
1
What do you mean by "not turned off" and "minimum system footprint"? Is it fully on or sleeping? Is the screen being refreshed? Is it accepting mouse/keyboard input? Can we ignore Wake-On-LAN which is not controlled by CPU?
– davidgo
Nov 24 at 18:24
@davidgo say the system is running on background, accepting ssh connections and runs a set of process that keeps the OS alive
– Rocky Li
Nov 24 at 18:26
1
I think it will be almost impossible to find this info - the best I could come up with was a detailed description of of power management for 4th gen mobile CPUs at intel.com/content/www/us/en/processors/core/…. While there is a minimal figure, practically it may make sense to tune the system with power top, set clock speeds to minimum and use a killawatt meter or similar to measure entire system draw. I'm GUESSING a figure of about 8 watts all up.
– davidgo
Nov 24 at 18:45
(also, tdp is not the expected maximum power consumption in real world loads, but not the maximum the CPU can actually use)
– davidgo
Nov 24 at 18:47
add a comment |
Your CPU itself will use virtually no power when using a c-state (ie cpu sleep state) other then 0. Almost all power used in sleep states are used by peripherals and especially RAM [the various sleep states determine what parts of the system are turned off]
– davidgo
Nov 24 at 1:29
1
What do you mean by "not turned off" and "minimum system footprint"? Is it fully on or sleeping? Is the screen being refreshed? Is it accepting mouse/keyboard input? Can we ignore Wake-On-LAN which is not controlled by CPU?
– davidgo
Nov 24 at 18:24
@davidgo say the system is running on background, accepting ssh connections and runs a set of process that keeps the OS alive
– Rocky Li
Nov 24 at 18:26
1
I think it will be almost impossible to find this info - the best I could come up with was a detailed description of of power management for 4th gen mobile CPUs at intel.com/content/www/us/en/processors/core/…. While there is a minimal figure, practically it may make sense to tune the system with power top, set clock speeds to minimum and use a killawatt meter or similar to measure entire system draw. I'm GUESSING a figure of about 8 watts all up.
– davidgo
Nov 24 at 18:45
(also, tdp is not the expected maximum power consumption in real world loads, but not the maximum the CPU can actually use)
– davidgo
Nov 24 at 18:47
Your CPU itself will use virtually no power when using a c-state (ie cpu sleep state) other then 0. Almost all power used in sleep states are used by peripherals and especially RAM [the various sleep states determine what parts of the system are turned off]
– davidgo
Nov 24 at 1:29
Your CPU itself will use virtually no power when using a c-state (ie cpu sleep state) other then 0. Almost all power used in sleep states are used by peripherals and especially RAM [the various sleep states determine what parts of the system are turned off]
– davidgo
Nov 24 at 1:29
1
1
What do you mean by "not turned off" and "minimum system footprint"? Is it fully on or sleeping? Is the screen being refreshed? Is it accepting mouse/keyboard input? Can we ignore Wake-On-LAN which is not controlled by CPU?
– davidgo
Nov 24 at 18:24
What do you mean by "not turned off" and "minimum system footprint"? Is it fully on or sleeping? Is the screen being refreshed? Is it accepting mouse/keyboard input? Can we ignore Wake-On-LAN which is not controlled by CPU?
– davidgo
Nov 24 at 18:24
@davidgo say the system is running on background, accepting ssh connections and runs a set of process that keeps the OS alive
– Rocky Li
Nov 24 at 18:26
@davidgo say the system is running on background, accepting ssh connections and runs a set of process that keeps the OS alive
– Rocky Li
Nov 24 at 18:26
1
1
I think it will be almost impossible to find this info - the best I could come up with was a detailed description of of power management for 4th gen mobile CPUs at intel.com/content/www/us/en/processors/core/…. While there is a minimal figure, practically it may make sense to tune the system with power top, set clock speeds to minimum and use a killawatt meter or similar to measure entire system draw. I'm GUESSING a figure of about 8 watts all up.
– davidgo
Nov 24 at 18:45
I think it will be almost impossible to find this info - the best I could come up with was a detailed description of of power management for 4th gen mobile CPUs at intel.com/content/www/us/en/processors/core/…. While there is a minimal figure, practically it may make sense to tune the system with power top, set clock speeds to minimum and use a killawatt meter or similar to measure entire system draw. I'm GUESSING a figure of about 8 watts all up.
– davidgo
Nov 24 at 18:45
(also, tdp is not the expected maximum power consumption in real world loads, but not the maximum the CPU can actually use)
– davidgo
Nov 24 at 18:47
(also, tdp is not the expected maximum power consumption in real world loads, but not the maximum the CPU can actually use)
– davidgo
Nov 24 at 18:47
add a comment |
1 Answer
1
active
oldest
votes
up vote
1
down vote
There is usually no official information about that number. Unless you count the computer powered off, so the lower bound of (almost) any CPU TDP would be 0W.
On modern low power CPU, is increasingly common to see something like "TDP up" and "TDP down", that are usually implemented as OS-selectable profiles that trades some performance for better power consumption and vice-versa. But these states are still refering to the maximum TDP in that state, it makes few sense to check for the minimum. You can see this for example on Ryzen 5 2500, that has 12/15(nominal)/25W TDP respectively: https://www.cpubenchmark.net/cpu.php?cpu=AMD+Ryzen+5+2500U&id=3123
This is very useful when you have limited cooling but can handle some bursts of high cpu load. Or with convertible tablets that have more power and cooling when docked.
If what you are asking is for minimum power consumption of a given chip under realistic conditions, you can check it manually with 3rd party utilities, like throttlestop or hwinfo, logging CPU power consumption while doing some light tasks.
While on C1E, a CPU like yours should consume about 7-8W (can vary a lot from one manufacturer to another)
answered Nov 23 at 17:36
Igb
1115
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
There is usually no official information about that number. Unless you count the computer powered off, so the lower bound of (almost) any CPU TDP would be 0W.
On modern low power CPU, is increasingly common to see something like "TDP up" and "TDP down", that are usually implemented as OS-selectable profiles that trades some performance for better power consumption and vice-versa. But these states are still refering to the maximum TDP in that state, it makes few sense to check for the minimum. You can see this for example on Ryzen 5 2500, that has 12/15(nominal)/25W TDP respectively: https://www.cpubenchmark.net/cpu.php?cpu=AMD+Ryzen+5+2500U&id=3123
This is very useful when you have limited cooling but can handle some bursts of high cpu load. Or with convertible tablets that have more power and cooling when docked.
If what you are asking is for minimum power consumption of a given chip under realistic conditions, you can check it manually with 3rd party utilities, like throttlestop or hwinfo, logging CPU power consumption while doing some light tasks.
While on C1E, a CPU like yours should consume about 7-8W (can vary a lot from one manufacturer to another)
answered Nov 23 at 17:36
Igb
1115
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
add a comment |
up vote
1
down vote
There is usually no official information about that number. Unless you count the computer powered off, so the lower bound of (almost) any CPU TDP would be 0W.
On modern low power CPU, is increasingly common to see something like "TDP up" and "TDP down", that are usually implemented as OS-selectable profiles that trades some performance for better power consumption and vice-versa. But these states are still refering to the maximum TDP in that state, it makes few sense to check for the minimum. You can see this for example on Ryzen 5 2500, that has 12/15(nominal)/25W TDP respectively: https://www.cpubenchmark.net/cpu.php?cpu=AMD+Ryzen+5+2500U&id=3123
This is very useful when you have limited cooling but can handle some bursts of high cpu load. Or with convertible tablets that have more power and cooling when docked.
If what you are asking is for minimum power consumption of a given chip under realistic conditions, you can check it manually with 3rd party utilities, like throttlestop or hwinfo, logging CPU power consumption while doing some light tasks.
While on C1E, a CPU like yours should consume about 7-8W (can vary a lot from one manufacturer to another)
answered Nov 23 at 17:36
Igb
1115
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
add a comment |
up vote
1
down vote
up vote
1
down vote
There is usually no official information about that number. Unless you count the computer powered off, so the lower bound of (almost) any CPU TDP would be 0W.
On modern low power CPU, is increasingly common to see something like "TDP up" and "TDP down", that are usually implemented as OS-selectable profiles that trades some performance for better power consumption and vice-versa. But these states are still refering to the maximum TDP in that state, it makes few sense to check for the minimum. You can see this for example on Ryzen 5 2500, that has 12/15(nominal)/25W TDP respectively: https://www.cpubenchmark.net/cpu.php?cpu=AMD+Ryzen+5+2500U&id=3123
This is very useful when you have limited cooling but can handle some bursts of high cpu load. Or with convertible tablets that have more power and cooling when docked.
If what you are asking is for minimum power consumption of a given chip under realistic conditions, you can check it manually with 3rd party utilities, like throttlestop or hwinfo, logging CPU power consumption while doing some light tasks.
While on C1E, a CPU like yours should consume about 7-8W (can vary a lot from one manufacturer to another)
answered Nov 23 at 17:36
Igb
1115
There is usually no official information about that number. Unless you count the computer powered off, so the lower bound of (almost) any CPU TDP would be 0W.
On modern low power CPU, is increasingly common to see something like "TDP up" and "TDP down", that are usually implemented as OS-selectable profiles that trades some performance for better power consumption and vice-versa. But these states are still refering to the maximum TDP in that state, it makes few sense to check for the minimum. You can see this for example on Ryzen 5 2500, that has 12/15(nominal)/25W TDP respectively: https://www.cpubenchmark.net/cpu.php?cpu=AMD+Ryzen+5+2500U&id=3123
This is very useful when you have limited cooling but can handle some bursts of high cpu load. Or with convertible tablets that have more power and cooling when docked.
If what you are asking is for minimum power consumption of a given chip under realistic conditions, you can check it manually with 3rd party utilities, like throttlestop or hwinfo, logging CPU power consumption while doing some light tasks.
While on C1E, a CPU like yours should consume about 7-8W (can vary a lot from one manufacturer to another)
answered Nov 23 at 17:36
Igb
1115
answered Nov 23 at 17:36
Igb
1115
answered Nov 23 at 17:36
Igb
1115
answered Nov 23 at 17:36
Igb
1115
1115
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
add a comment |
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
@lgb Are you sure this is correct - it seems wrong? I understood that the entire system used about 8watts, not the CPU and I know memory requires a surprising amount of power. I also had a first gen i5 processor - so prior to Intel push for power efficiency - which I ran for extended periods without any active cooling (no fan on motherboard or PSU) by underclocking it, which says to me the CPU, when not busy, does not dissipate much power.
– davidgo
Nov 24 at 1:35
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
You can check it yourself with any of the utilites I mentioned, motherboard sensors usually give a very reasonable estimation. Keep in mind that even 15W is a very low ammount of power, it can be dissipated passively, specially if you can afford to lose some bins of the turbo multiplier without problem. Ram is usually not a power hungry component, specially since you have DDR3L in your notebook (ddr4 in desktop is about 2W per module, it should be near that figure). Highest power consumption usually comes, by far, from cpu-gpu-screen (not neccessarily in this order, depends on many factors)
– Igb
Nov 24 at 17:42
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
That's not logical - you can't run utilities when the CPU is in a non c0 state. 8 watts is a massive amount of power in this scenario. Thinking some more - I have a Venue11 (4th gen i5 CPU) with a 36 watt hour battery. Battery depletion in this model in sleep mode runs at < 2% per hour, meaning a total current draw of less then 0.72 watts per hour all up. Power draw WHEN IN USE is typically about 15 watts - ie a little over 2 hours runtime.
– davidgo
Nov 24 at 18:12
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
@gbt looks like my previous comment got eaten.Your C1E power claim of 7 watts for CPU makes no sense. In full sleep mode (not hibernate) my 4th gen I5 laptop (Venue 11) with 36 watt hour battery had a standby time of less then 1% per hour, so less then 0.36 watts.
– davidgo
Nov 24 at 19:00
add a comment |
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Your CPU itself will use virtually no power when using a c-state (ie cpu sleep state) other then 0. Almost all power used in sleep states are used by peripherals and especially RAM [the various sleep states determine what parts of the system are turned off]
– davidgo
Nov 24 at 1:29
1
What do you mean by "not turned off" and "minimum system footprint"? Is it fully on or sleeping? Is the screen being refreshed? Is it accepting mouse/keyboard input? Can we ignore Wake-On-LAN which is not controlled by CPU?
– davidgo
Nov 24 at 18:24
@davidgo say the system is running on background, accepting ssh connections and runs a set of process that keeps the OS alive
– Rocky Li
Nov 24 at 18:26
1
I think it will be almost impossible to find this info - the best I could come up with was a detailed description of of power management for 4th gen mobile CPUs at intel.com/content/www/us/en/processors/core/…. While there is a minimal figure, practically it may make sense to tune the system with power top, set clock speeds to minimum and use a killawatt meter or similar to measure entire system draw. I'm GUESSING a figure of about 8 watts all up.
– davidgo
Nov 24 at 18:45
(also, tdp is not the expected maximum power consumption in real world loads, but not the maximum the CPU can actually use)
– davidgo
Nov 24 at 18:47