Do i7's have power saver if idle?

[ak47carbine]

I've read some comments that. Example my i7 920 is idle. The processor will only use 1core @ 1.60ghz. Is this true?

 

[Gulli]

No, all cores will remain active, but the "Intel Speedstep" function (if it's not disabled in the BIOS) will throttle clockspeeds and core voltages back when idle, effectively reducing power consumption, but even without speedstep any CPU consumes less power when idle.

 

[ak47carbine]

thanks for the reply..
the i7 920 requires 130w. so does it mean.. it idles at 130w? or it will reduce?

 

[Gulli]

thanks for the reply..
the i7 920 requires 130w. so does it mean.. it idles at 130w? or it will reduce?

It will consume much less at idle.
It consumes 130W at full load at stock speed, full load means all cores 100% active, that won't happen with daily use or even gaming.

 

[cjl]

No, all cores will remain active, but the "Intel Speedstep" function (if it's not disabled in the BIOS) will throttle clockspeeds and core voltages back when idle, effectively reducing power consumption, but even without speedstep any CPU consumes less power when idle.

The i7 has the capability to fully shut down idle cores, not just throttle them back. This is part of the reason the new i5 and 1156 i7 CPUs have such low idle power.

 

[Gulli]

The i7 has the capability to fully shut down idle cores, not just throttle them back. This is part of the reason the new i5 and 1156 i7 CPUs have such low idle power.

Yes, but I don't think the 920 has that feature.

 

[ak47carbine]

Ok, now it is clear to me. Thank you so much guys.

 

[cjl]

Yes, but I don't think the 920 has that feature.

Every i7 has that feature. The socket 1366 models still take a lot of power at idle (comparable to older core 2 quads) because the northbridge and all the RAM takes a decent amount of power, but the newer ones really show the benefit.

 

[ak47carbine]

in your instinct
so how many watts at idle??

 

[Gulli]

in your instinct
so how many watts at idle??

Maybe 30W to 50W, but that's just my gut feeling, could just as well be 15W, but when looking for a PSU you always have to keep a 100% loaded CPU in mind.

 

[yomamafor1]

30W to 50W sounds about right.

 

[kg4icg]

At idle my cpu is only doing 10 watts at .918v and it's still set at stock, were do you get 30-50 watts at idle for a I7-920?

 

[sminlal]

in your instinct
so how many watts at idle??

CPUID shows my Core i7 920 at a little under 50W at idle.

 

[yomamafor1]

At idle my cpu is only doing 10 watts at .918v and it's still set at stock, were do you get 30-50 watts at idle for a I7-920?

Just curious. How do you get that figure?

 

[cjl]

CPUID shows my Core i7 920 at a little under 50W at idle.

I'd bet the CPU alone uses quite a bit less than that. With the northbridge and memory, that could be about right though.

 

[kg4icg]

there is a utility for gigabyte boards called dynamic energy saver that shows wattage used by the cpu. it woks quite well.

 

[cjl]

But is it correct? I've yet to find a power utility like that that I would trust.

 

[sminlal]

The Intel datasheet shows that the CPU itself consumes 12W of power in the C6 state - that's the lowest possible power level before entering sleep state with the processor clocks quiesced and the register contents flushed out to cache. So if you consider that to be "idle" then yeah, that's the official power consumption of the chip.

What I treat as "idle" is when the CPU is active and responding to user input, but with the cores at essentially zero percent utilization - and under that definition mine is consuming a tad less than 50W.

 

[Gulli]

The Intel datasheet shows that the CPU itself consumes 12W of power in the C6 state - that's the lowest possible power level before entering sleep state with the processor clocks quiesced and the register contents flushed out to cache. So if you consider that to be "idle" then yeah, that's the official power consumption of the chip.

What I treat as "idle" is when the CPU is active and responding to user input, but with the cores at essentially zero percent utilization - and under that definition mine is consuming a tad less than 50W.

I agree, and it also depends on the vcore that's being applied to the chip: "auto" settings doesn't necessarily mean "lowest vcore possible".

 

[ak47carbine]

I see, i haven't overclock my i7 920 it is still @
2.66ghz.. So what is the suggested vcore? Thank you.

 

[ak47carbine]

Well thats a good grief.. I thought the cpu idle power reaches 100w or something.. now the gpu, im worried about,.

 

[Gulli]

I see, i haven't overclock my i7 920 it is still @
2.66ghz.. So what is the suggested vcore? Thank you.

Depends, I've got 1.21875V for 3.2ghz, but every chip is different.

 

[cjl]

Every chip is different - if you don't plan on overclocking, leave it on auto though. If you do plan to overclock, the recommended maximum is either 1.375V or so, or 80C full load (some people will say a bit lower than this). You can overclock as far as you want until you hit one of these limits. In many cases with the i7, you'll hit the thermal limit first though.

 

[ak47carbine]

ok thank you so much guyz.. i really appreciate all your help.. one last question..up to now i havent applied some thermal paste in my cpu.. but the stock hsf had some pre applied thermal paste. is it ok?? im not planning to overclock my i7 920 ..

 

[cjl]

It should be fine, yes.