RAPL Output Queries

[gokussj9]

Hi,

I used the code from http://web.eece.maine.edu/~vweaver/projects/rapl/rapl_msr.c to get the

energy readings.The outut on my system is

Power units = 0.125W
Energy units = 0.00001526J
Time units = 0.00097656s

Package thermal spec: 95.000W
Package minimum power: 64.000W
Package maximum power: 150.000W
Package maximum time window: 0.046s

Package energy before: 22006.639099J
PowerPlane0 (core) for core 11 energy before: 19797.750381J
DRAM energy before: 54420.965775J

Sleeping 1 second

Package energy after: 22027.184555 (20.545456J consumed)
PowerPlane0 (core) for core 11 energy after: 19804.504456 (6.754074J consumed)
DRAM energy after: 54423.153534 (2.187759J consumed)

I have an two Intel Xeon E5-2650 http://ark.intel.com/products/64590/ processors as two sockets on my compute node.

Since I am using a server processor, what does

1) package energy means- does it mean the 8 core processor chip + GPU or DRAM energy usage?

2) Power Plane 0- Does it report the energy  usage for only core 0?

3) DRAM- is the figure reporting the idle power usage of the DRAM chips?

Thanks

[Bernard]

Hi,

there is a difference between client and server platform when power management is considered.

1. Package domain is the processor die.I think that gpu is considered as belonging to client domain.

2,No , PP0 is per package.

3.How the sleeping in the source code is implemented.Is it related to P-states?

[gokussj9]

iliyapolak wrote:

Hi,

there is a difference between client and server platform when power management is considered.

1. Package domain is the processor die.I think that gpu is considered as belonging to client domain.

2,No , PP0 is per package.

3.How the sleeping in the source code is implemented.Is it related to P-states?

Thanks for your reply

If PP0 is the processor Die that means 8 core Die is consuming only 7 watts as Idle Power and the PP0 along with GPU 

is consuming 20 watts?

Sleeping in source code is implemented using sleep() function.

[Patrick_F_Intel1]

The scope of the PP0 MSR is 'per package' but the value in the MSR is the total energy used by the 8 cores on the package.

Yes, the processor is saying it is consuming only 7 watts in idle but I don't think the server chip (ivy-bridge-EP) has the GPU like client ivy-bridge chips. Or at least the SNB-EP data sheets volume 1 & 2 never mentions a GPU whereas the client SNB datasheets spend a lot of time talking about the graphics unit.

The processor domain is the cores and the uncore so the 20 watts is the cores+uncore.

Pat

[gokussj9]

Patrick Fay (Intel) wrote:

The scope of the PP0 MSR is 'per package' but the value in the MSR is the total energy used by the 8 cores on the package.

Yes, the processor is saying it is consuming only 7 watts in idle but I don't think the server chip (ivy-bridge-EP) has the GPU like client ivy-bridge chips. Or at least the SNB-EP data sheets volume 1 & 2 never mentions a GPU whereas the client SNB datasheets spend a lot of time talking about the graphics unit.

The processor domain is the cores and the uncore so the 20 watts is the cores+uncore.

Pat

Isn't 20 watts a little too less of idle power for an 8 core processor? Even the K20 GPU I have on the same

node has Idle power around 30 watts?

[Bernard]

I think that server cpu does not have on-die gpu.ISDM clearly states that there is difference between client  and server platform.

>>>If PP0 is the processor Die that means 8 core Die is consuming only 7 watts as Idle Power and the PP0 along with GPU 

is consuming 20 watts?>>>

As Pat pointed it out.Yes it is measured on client platform including power dissipation of gpu.

[Bernard]

>>>Sleeping in source code is implemented using sleep() function>>>

How that code is trying to put processor in lower power state by using Win API sleep function?Currently executing thread will yield the cpu and  next ready queue or deffered ready thread will run.I do not understand what this code try to achieve by using sleep functions.