Intel C2D power-saving features

[hades]

Hello...

Just wondering how my Intel C2D 6300 does its power-saving features. On my centrino laptop I can see the speed fluctuate between 600mhz and 1.6ghz depending on the need. But how does this work on the desktop? According to CPU-Z my CPU is going full-blast all the time. It has a multiplier of 7, the best I could do is switching my power-scheme to Laptop which made the multiplier fluctuate between 6 and 7 depending on the need. But this is pretty weak... Does it do its power saving thingy in the background, switching off parts of the chip when not needed? Just wondering...

hades

[fitbrit]

Maybe it doesn't save power because you have an external power source (i.e. not battery) for your desktop? Just a guess... also awaiting expert opinions on this.

[Amourek]

I think it's because the E6300 has a low multiplier and the lowest it can drop the multiplier is to 6. I just built a E4300 system for a friend (9x200) and Vista drops it to 6 as well.

[board123]

E6600 can go from 6x to 9x resulting in a 800 MHz change. You just have to enable Speedstep in the bios. If you're using Vista there's a built in Speedstep control thing.

Oh, and it might not be called "Speedstep" in the bios.

[Cafe_333]

I think it's because the E6300 has a low multiplier and the lowest it can drop the multiplier is to 6. I just built a E4300 system for a friend (9x200) and Vista drops it to 6 as well.Yup, this is the correct answer. The lowest multiplier Intels can drop to is 6x.

Your clock speed is determined by the bus speed and the cpu's multiplier. Your E6300's (actual) bus speed is 266mhz, multiply that by 7 and that's how you get 1.86GHz. With speedstep enabled, the lowest it can drop the multiplier is 6, so you only see the clock drop down to 1.6GHz (6x266).

With your centrino laptop, its bus speed is 100mhz with a sick multiplier of 16x. So at full throttle it runs at 1600mhz. With speedstep enabled it too will only drop the multiplier down to 6x which equals 600mhz.

[ES_Revenge]

With your centrino laptop, its bus speed is 100mhz with a sick multiplier of 16x. So at full throttle it runs at 1600mhz. With speedstep enabled it too will only drop the multiplier down to 6x which equals 600mhz.
Hence why the new laptop parts are prefixed with "T" or "L" instead of "E". The laptop parts usually have higher core/bus ratios (mutlipliers) for exactly this reason. Since power saving isn't as much of a concern on a desktop, the "E" prefix C2Ds consume more power. Furthermore the desktop processors are usually a lot cheaper for the same performance levels.

[masterc]

Excellent thread folks!!
I Learned something new...

[fitbrit]

Excellent thread folks!!
I Learned something new...

I did too.

[hades]

Same. Great answers! :) Thank you for the explanation!

So there is no practical point in my enabling the Laptop setting under the power control panel, since the change from a multiplier from 7 to 6 is negligible. No biggie.

Thanks!

hades

[Amourek]

It will save some power. It not only drops the multi to 6 but should reduce voltage to 1.15V.