Intel and C States


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I have a basic understanding of what C States are basically power management states for the CPU as requested by the OS...

 

Right now I have an i5 ivy bridge CPU..

 

What is the best configuration to set up in BIOS for C States... C1E is always disabled by default it seems, and everything else set to auto... should C1E be disabled? what do you guys normally use? I'm trying to get the OS to manage power states as efficiently as possible

 

 

before someone asks, no I am not over clocking this system, I just want to get speed step / C States in the best combination for power efficiency

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If you're not overclocking then you can enable all c-states, including C1E, as well as making sure speedstep is enabled.  The OS will manage the CPU and clock down as necessary as long as your power profile is "Balanced".  High Performance will ramp the CPU up to fill clock 100% of the time where balanced will only throttle up when the load is high enough to warrant it.

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Any idea what the minimum processor state is for an i5 ivy bridge 3570k series chip? Under balanced power management the min processor state is set to 5% but I never see the CPU Minimum frequency drop below 50% in resource monitor, which leads me to believe it never goes less then half CPU power with all C States and speed step enabled

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I guess I should say it this way, the max speed of the CPU is 3.4GHz, I've never seen it go below 1.6GHz, I assume this is the normal minimum even though windows is set to 5% of max as the min

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AFAIK the full throttle down clock should be 800MHz on that chip, check the idle clock with CPU-Z, task manager likes to bounce around a lot.

 

That system (different one then the one I am on now) sitting idle in CPU-Z is reporting Core speed at 1599.63MHz multiplier x 16.0 (16 - 38) bus speed 99.98MHz

 

and cpu usage is at 0% and has been sitting in that state for a while now...

 

not sure what I am missing that is stopping the clock from throttling down more...

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That system (different one then the one I am on now) sitting idle in CPU-Z is reporting Core speed at 1599.63MHz multiplier x 16.0 (16 - 38) bus speed 99.98MHz

 

and cpu usage is at 0% and has been sitting in that state for a while now...

 

not sure what I am missing that is stopping the clock from throttling down more...

Oh, if it says 16-38 then the min multi is 16 which is 1.6GHz, so you're good then.

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well hows this for annoying, I went into the BIOS setup restored the defaults turned C1E back on and speed step... nothing else changed... and now it will not post... just does a never ending reboot loop on post... does a few POST debug codes then restarts.... repeat... ugh

 

I've never OC'ed this system, never changed voltages, multipliers, etc, only enabled the energy efficiency stuff..... which worked great until I asked this question  :rofl:

 

ugh... overnighting a new motherboard and processor now guess I get to upgrade my "old" Ivy Bridge Z77 system to a Z97 chipset and a i5-4690K CPU... praying the memory is ok so I can reuse that at lease

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well hows this for annoying, I went into the BIOS setup restored the defaults turned C1E back on and speed step... nothing else changed... and now it will not post... just does a never ending reboot loop on post... does a few POST debug codes then restarts.... repeat... ugh

Did you not try to clear the COMS in order to rest the BIOS?

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Did you not try to clear the COMS in order to rest the BIOS?

of course I did!

 

I tried that using the CMOS_REST button on the back of the motherboard it didn't do anything

 

I tried the Battery jumper short... didn't do anything

 

pulled the power completely pulled the CMOS button cell battery drained all the cap power by turning it on after it was 100% disconnected from anything external (monitor, Ethernet, all usb, power, etc)

 

didn't do anything

 

according to MSI support this can happen if the BIOS chips get corrupted, of course their response was it's redundant BIOS so switch the switch from A to B... well guess what, that one isnt' working either... that one boots through POST to the point it says A2 as the BIOS code (which means IDE Detect) and just hangs there and never moves... I let it set for over an hour and nothing with all but the CPU and a single stick of DDR3 4GB left out of 4 (I tried all 4 in all combos also)

 

so MSI basically said the BIOS is shot and I have to RMA it... ugh good thing is it has a 3yr parts and labor warranty, and that ends for this board 5/1/2015...

 

bad news is I need a system running like right now to get work done so I had to order a new motherboard, and CPU over night shipping to get it here tomorrow... (MSI Z98 motherboard with an Intel i5-4690k) so it will be a little upgrade, but at lease I'll have something while MSI does the RMA on the board... then I can turn that board / CPU into a backup system when it comes back

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when I am on the other BIOS selection, it gets to a status code 0x57 which means CPU Mismatch before it reboots... which makes no sense, considering this is a Z77 motherboard, with an i5 Ivy Bridge CPU... which it has been running fine with for about 2yrs!

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of course I did!

 

I tried that using the CMOS_REST button on the back of the motherboard it didn't do anything

 

I tried the Battery jumper short... didn't do anything

 

pulled the power completely pulled the CMOS button cell battery drained all the cap power by turning it on after it was 100% disconnected from anything external (monitor, Ethernet, all usb, power, etc)

 

didn't do anything

 

according to MSI support this can happen if the BIOS chips get corrupted, of course their response was it's redundant BIOS so switch the switch from A to B... well guess what, that one isnt' working either... that one boots through POST to the point it says A2 as the BIOS code (which means IDE Detect) and just hangs there and never moves... I let it set for over an hour and nothing with all but the CPU and a single stick of DDR3 4GB left out of 4 (I tried all 4 in all combos also)

 

so MSI basically said the BIOS is shot and I have to RMA it... ugh good thing is it has a 3yr parts and labor warranty, and that ends for this board 5/1/2015...

 

 

 

How did you press the button? Power still to the board with lights on but not actually running? As from what I've read with all these boards for the CMOS reset on the I/O. Power should be disconnected.

 

 

bad news is I need a system running like right now to get work done so I had to order a new motherboard, and CPU over night shipping to get it here tomorrow? (MSI Z98 motherboard with an Intel i5-4690k) so it will be a little upgrade, but at lease I'll have something while MSI does the RMA on the board? then I can turn that board / CPU into a backup system when it comes back

 

Right on the weekend as well. You shouldn't have been messing with your system if it was that crucial.

 

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How did you press the button? Power still to the board with lights on but not actually running? As from what I've read with all these boards for the CMOS reset on the I/O. Power should be disconnected.

 

 

 
 

Right on the weekend as well. You shouldn't have been messing with your system if it was that crucial.

 

 

It's not "crucial" in the sense i can't do work, it just makes the work easier... i have other systems also, guess I sounded a bit exagerated there lol

 

and as for how I reset it, I followed their guide that said disconnect power, press the button then restart.. it clearly says dont do it while powered on or it could cause issues

Are you not able to flash the bios?

 

how exactly would I do that if I can't even get the system to fully POST :P

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This is why unless overclocking just stay out of BIOS and don't make changes, you were likely to get little to no improvement futsing around in there and now you broke it 

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Your PSU needs to support lowered power states like the ones you are talking about. Further, C states relate more to sleep/idle functions than to clock rates.

 

Regarding your issue, I would download the latest bios for your motherboard, use your second bios chip to boot into bios and flash the new bios with MSI's bios tool.

 

If that doesn't work, sounds like you might have written that board off unless you can find an older stepping of the chip.

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This is why unless overclocking just stay out of BIOS and don't make changes, you were likely to get little to no improvement futsing around in there and now you broke it 

 

You know, I've made changes in BIOS hundreds of times over my life... never a single issue, this time I have no idea what happened, it has to be a bug in their UEFI setup program, not to mention the design of it to take out both BIOS chips at the same time.... making power state changes isn't just limited to overclocking... some of us care more about efficiency also

Your PSU needs to support lowered power states like the ones you are talking about. Further, C states relate more to sleep/idle functions than to clock rates.

 

Regarding your issue, I would download the latest bios for your motherboard, use your second bios chip to boot into bios and flash the new bios with MSI's bios tool.

 

If that doesn't work, sounds like you might have written that board off unless you can find an older stepping of the chip.

Like I said, both bioses went bad at the same time... neither will boot, which is why I think this has nothing to do with me making such a basic change as enabling C1E... that should not corrupt two bios chips

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of course I did!

 

I tried that using the CMOS_REST button on the back of the motherboard it didn't do anything

 

I tried the Battery jumper short... didn't do anything

 

pulled the power completely pulled the CMOS button cell battery drained all the cap power by turning it on after it was 100% disconnected from anything external (monitor, Ethernet, all usb, power, etc)

 

didn't do anything

 

according to MSI support this can happen if the BIOS chips get corrupted, of course their response was it's redundant BIOS so switch the switch from A to B... well guess what, that one isnt' working either... that one boots through POST to the point it says A2 as the BIOS code (which means IDE Detect) and just hangs there and never moves... I let it set for over an hour and nothing with all but the CPU and a single stick of DDR3 4GB left out of 4 (I tried all 4 in all combos also)

 

so MSI basically said the BIOS is shot and I have to RMA it... ugh good thing is it has a 3yr parts and labor warranty, and that ends for this board 5/1/2015...

 

bad news is I need a system running like right now to get work done so I had to order a new motherboard, and CPU over night shipping to get it here tomorrow... (MSI Z98 motherboard with an Intel i5-4690k) so it will be a little upgrade, but at lease I'll have something while MSI does the RMA on the board... then I can turn that board / CPU into a backup system when it comes back

 

So everything was carried out like this? http://www.tomshardware.co.uk/forum/315348-30-z77a-gd65-boot-loop-edit-reset-bios-bios

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Its unlikely but maybe when you enabled the C States the PSU went?

nope, PSU is fine, I am using it right now on my new motherboard

I followed MSI's instructions exactly and that didn't help, I followed multiple write ups other people wrote including that one, didn't help

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OOoh just noticed something odd about the motherboard... near the two BIOS IC's there are 4 caps... two of them are bulged... ugh wonder if it's just a coincidence with me asking about power levels and the caps going bad... MSI claims they use better quality caps but doesn't mean they can't still fail...

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well, got the new board today, MSI's RMA process is very fast... the longest part was the transit times since they shipped it back via UPS ground which took 5 days from california

 

the repair description sounds like the board was already going bad, and not the fault of BIOS settings

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