AMD CPU core load

[whatismyproblem]

Hi all...
I have and AMD Phenom II X4 840

out of cores 0, 1, 2, 3
core 1 has a high load at idle
why??

 

[mace200200]

Most Phenom II cpus will put load on a single core if it can because it saves power, and therefor lowers the amount of heat generated, mine will do this to when i run certain programs.


AMD CoolCore™ Technology

Reduces processor energy consumption by turning off unused parts of the processor. For example, the memory controller can turn off the write logic when reading from memory, helping reduce system power.
Works automatically without the need for drivers or BIOS enablement.
Power can be switched on or off within a single clock cycle, saving energy with no impact to performance.
Benefit: Helps users get more efficient performance by dynamically activating or turning off parts of the processor.

 

[$hawn]

Most Phenom II cpus will put load on a single core if it can because it saves power, and therefor lowers the amount of heat generated, mine will do this to when i run certain programs.

I really doubt it....mostly there's a single threaded application running in the background.

If there are multiple idle task threads to be executed, it makes more sense for the OS to run them on 4 separate cores @800MHz, rather than on a single core @3.2GHz. This is because as clock speeds increase, the power dissipated by the core increases following a squarish kind of law, giving off more heat.
Same reason why server chips have more number of cores that are clocked slower than desktop chips....its more energy efficient

Phenom II chips CANNOT switch off individual cores. The best they can do is idle them at 800MHz.

 

[mace200200]

Thats just what I read off of AMDs web sites, I guess I must of misunderstood it then.

 

[whatismyproblem]

I really doubt it....mostly there's a single threaded application running in the background.

If there are multiple idle task threads to be executed, it makes more sense for the OS to run them on 4 separate cores @800MHz, rather than on a single core @3.2GHz. This is because as clock speeds increase, the power dissipated by the core increases following a squarish kind of law, giving off more heat.
Same reason why server chips have more number of cores that are clocked slower than desktop chips....its more energy efficient

Phenom II chips CANNOT switch off individual cores. The best they can do is idle them at 800MHz.

Will Ivy Bridge turn off cores??

 

[$hawn]

Will Ivy Bridge turn off cores??

Again no...but it can turn off significant portions of the chip to save power.

Read the 3rd paragraph,
http://www.anandtech.com/show/4830/intels-ivy-bridge-architecture-exposed/3

Also, even under full load, IB draws only 77W, that's almost 45W less than the Phenom II. So don't worry, IB is a extremely energy efficient chip, and is also extremely fast. So go ahead and buy it

 

[whatismyproblem]

Best answer selected by whatismyproblem.