Question about cpu core voltage (i5 2500k)

[Deleted]

Hi there,

As the thread title says, I've got a little question on as to how the cpu core voltage should operate during overclocks. When on standard clocks (3.3ghz) the core voltage goes (0,960V @ 1.6ghz) and (1.250ishV @ 3.3 ghz). Now when I overclock (say 1.3V @ 4ghz), the voltage ALWAYS stays at 1.3V, even when downclocked to 1.6ghz. Is this normal and should I be worrying about the processor consuming a whole lot more power even in idle?

Thanks in advance!

-Access

[ispano]

The Downclocking and Downvolting is due to Speedstep. I've noticed, even on other i7 series, that the downvolting only occurs if not overclocked at all or only if the Voltage is set to default or auto.

[Deleted]

Thanks, clear enough. Any reason to be afraid of increased (significant) power consumption at 1.3V? Also, my chip required me to put as much as 1.37V to reach a stable 4.5ghz which seems to be too high for 24/7 usage, correct?

[Deleted]

Ah crap. I wrote a long post for you and then my internet died on me.

Oh well. I'd suggest not going over 1.4V unless you know what you are doing. 1.37V is stretching it for 4.5GHz, but it isn't high - all chips are different. In short, don't worry too much about the Vcore, worry about temperatures instead. When overclocking, remember to take a small step every time. Don't jump from 4.0 to 4.5 to 4.9.

[Deleted]

Thanks for the advice . The maximum core temps respectively were: 56-63-63-60 during prime 95. This is alright isn't it?

Forgot to mention, this is at 1.37V, 4.5ghz

[Deleted]

Thanks for the advice . The maximum core temps respectively were: 56-63-63-60 during prime 95. This is alright isn't it?

Forgot to mention, this is at 1.37V, 4.5ghz

That's some good temps. You only need to get worried when they reach 80-90c under full load. What cooling are you running?

[Saithes]

The Downclocking and Downvolting is due to Speedstep. I've noticed, even on other i7 series, that the downvolting only occurs if not overclocked at all or only if the Voltage is set to default or auto.

False for sandybridge! The downvolting applies when Offset voltages are used. Manual/Fixed voltages run a constant voltage all the time. So in short... Fixed/Manual Voltage will not downvolt but Offset Mode will.
Example:

[Deleted]

That's some good temps. You only need to get worried when they reach 80-90c under full load. What cooling are you running?

Good to hear . I'm using the Scythe Mugen 2 Rev B with Artic zero 5 cooling paste. Idle temps get as low as 25 for brief moments, usually between 27-31 :P

---------- Post added 2011-07-30 at 06:38 PM ----------

False! The voltage downclocking applies when Offset voltages are used. Manual/Fixed voltages set the voltage to a constant all the time.

I believe that's exactly what he said :O. He stated that downclocking also occurs when the voltage is set to auto. Or did you mean something else?

[Deleted]

Good to hear . I'm using the Scythe Mugen 2 Rev B with Artic zero 5 cooling paste. Idle temps get as low as 25 for brief moments, usually between 27-31 :P

Guess you have a cool room then. I'm lucky to get my room temp below 30 now during the summer, and as a result my CPU idles around 35-45.

[Deleted]

Guess you have a cool room then. I'm lucky to get my room temp below 30 now during the summer, and as a result my CPU idles around 35-45.

Move to Holland if you want a cool room, the weather sucks here

[Saithes]

I believe that's exactly what he said :O. He stated that downclocking also occurs when the voltage is set to auto. Or did you mean something else?

Auto is not Offset. Offset lets you add or subtract an amount of voltage from the stock VCore. Like this:



See the "OFFSET MODE" next to the CPU Voltage then the - sign and the "CPU Offset Voltage"? It's the only way you can get it to downvolt while being overclocked.

Manual Mode = Fixed Voltage and won't downvolt.
Offset Mode = Added/Subtracted Voltage that will allow downvolting.

Auto would entail it simply scales with the clock speed.

My example from my earlier post:


Using Offset Mode it drops to 1.1v on idle and 1.46v on load.

[Deleted]

Auto is not Offset. Offset lets you add or subtract an amount of voltage from the stock VCore. Like this:



See the "OFFSET MODE" next to the CPU Voltage then the - sign and the "CPU Offset Voltage"? It's the only way you can get it to downvolt while being overclocked.

Manual Mode = Fixed Voltage and won't downvolt.
Offset Mode = Added/Subtracted Voltage that will allow downvolting.

Auto would entail it simply scales with the clock speed.

My example from my earlier post:


Using Offset Mode it drops to 1.1v on idle and 1.46v on load.

Awesome, never heard of offset mode, in fact, I'm not even sure if my motherboard (msi gd-53) has that option oO. I'll check it out later

---------- Post added 2011-07-30 at 07:32 PM ----------

As suspected, I don't even have an offset mode =/