Interesting information on Core 2 Duo and power consumption

[DavidC1]

Nobody noticed this, but check this out:
http://download.intel.com/design/processor/datashts/31327801.pdf

Go to page 78 of the datasheet. Take a look at Extended HALT power.

Every Core 2 Duo CPU is at 22.0W, EXCEPT the E6700, which is at 20.0W. This is not a typo. This is binning by power consumption. Charlie(Inquirer) mentioned that Core 2 Duo are binned by power consumption, which meant highest end CPU consumes LESS power. People may then wonder why is not the X6800 that consumes least power since its the top-end. I'd say the explanation is that X6800 is a more performance oriented part, while E6700 is the highest mainstream. You can see in measurements its actually true, E6300/E6400 consumes more power than its 4MB cache, higher clocked brothers!!: http://www.xbitlabs.com/articles/cpu/display/core2duo-shootout_11.html

It's true in idle that higher end CPUs consume less power. It's different in load and takes a different turn.

However, I would say it depends on the application. Due to the advanced power management of the Core 2 Duo CPUs, there will be a case where 4MB parts are going to consume less power than the 2MB parts in some cases even if peak power measurements indicate otherwise, since 4MB parts can finish the task quicker and go to idle mode.

 

[crow_smiling]

The Xbitlabs article shows the X6800 consuming the least amount of power at idle, with the E6600 & E6700 being equal; which is contradicting Intel’s data.
The Xbitlabs test was performed with Speedstep disabled, which may not make the data sets directly comparable anyway!

I have an E6400 & E6600 at hand, so I’ll compare them. I can only measure power consumption for the whole system, but that should be good enough.

 

[Action_Man]

For the desktop, not so interesting. For notebooks, somewhat interesting.

 

[crow_smiling]

How do I measure the CPU power in the Extended Halt state? I mean, how do I actually trigger this state? There are so many Extended & Enhanced Halt states that I’m not sure which one Intel refer to in their documentation. I have the Intel Thermal Analysis Tool installed which does show the C state of each core, I just don’t know which C State to look out for.

 

[crow_smiling]

For the desktop, not so interesting. For notebooks, somewhat interesting.

The documentation for the mobile CPUs shows one set of figures for both the 2 and 4 MB cache CPUs. It does show the TDP for 5 different low power states though. See Table 16 on page 72.

 

[crow_smiling]

We're talking about Conroe (especially E6700) being able to run lower voltage (therefore lower power) than Allendale at the same clockspeed or in E-HALT state.

So how do I put my system into the Extended HALT state and check that it is there?

 

[crow_smiling]

We're talking about Conroe (especially E6700) being able to run lower voltage (therefore lower power) than Allendale at the same clockspeed or in E-HALT state.

So how do I put my system into the Extended HALT state and check that it is there?

Remember, my brain thinks of this issue/event in the opposite direction as Action_Man pointed out.
If one wants to use it in a HTPC they should've gone with X2 3800+ SFF EE instead. A C2D for that would be wasteful, they are reserved for overclockers only.
Or went with Merom + AOpen 975X YDG for HTPC. (which is still wrong because I'd rather over that damn thing! :lol: )

When people ignore the question in hand it usually means they don’t know the answer.
Does anyone else know the answer to this question?

 

[gOJDO]

The most precise way to measure the exact spend energy is to measure before the psu. Let both CPUs do the same tasks(Prime, 3DMark, etc.....) for some time(hour, two, day...) using the same settings and conditions.

 

[crow_smiling]

If you actually read the content what the OP posted, it's really about binning and not about power consumption as the thread title suggested. Binning=higher OC

Yeah, I read the speculation. Since when is binning by Power Consumption not about Power Consumption? Just because you want to look at it from one perspective, doesn’t mean that other perspectives aren’t equally valid, unless you’re a fascist.