what is the Vcore when computer is in sleep mode?

[Yanif]

I have set Vcore of my i7-4790k on manual mode in BIOS, meaning the cpu core is fed a constant voltage of 1.247v on 24/7 basis. I just wonder what the Vcore will be if the computer goes to sleep. Is it zero? same as shutting it down? or still 1.247v?

 

[Darkbreeze]

No, in sleep mode, unless you have turned off Intel speed step and have the min and max processor states in processor power management settings in the advanced control panel power profile settings set to 100%, it should drop to a very low core voltage. It will not run at it's set voltage unless you force it to, in which case you really won't be in sleep and will likely have other issues as the system would overheat with it sleeping but that kind of voltage still being applied.

Is there a specific reason you are wanting to know this, or are you just curious?

 

[icraft]

During normal sleep mode the CPU should drop to a very very low voltage number. If you are truly set to a constant voltage I'm not sure how it would work though. However, manual mode may not be fully manual. On my MSI motherboard "manual" set to 1.2v maxes at 1.224 but can lower itself down to 0.196 while the PC is on. I can also set a forced manual mode that keeps it at 1.2 always.

 

[Yanif]

No, in sleep mode, unless you have turned off Intel speed step and have the min and max processor states in processor power management settings in the advanced control panel power profile settings set to 100%, it should drop to a very low core voltage. It will not run at it's set voltage unless you force it to, in which case you really won't be in sleep and will likely have other issues as the system would overheat with it sleeping but that kind of voltage still being applied.

Is there a specific reason you are wanting to know this, or are you just curious?

Yes. I disabled intel speedstep plus C-states, and manually set both min and max cache ratio to 40, and cpu ratio to 47. I ask this because 1) I am worried if the voltage and frequency is not dropped in sleep mode, putting into sleep mode will do more harm because all the fans are stopped, 2) I saw the computer have trouble staying in sleep mode. After a lot of trouble shooting, I begin to ask why.

 

[Yanif]

During normal sleep mode the CPU should drop to a very very low voltage number. If you are truly set to a constant voltage I'm not sure how it would work though. However, manual mode may not be fully manual. On my MSI motherboard "manual" set to 1.2v maxes at 1.224 but can lower itself down to 0.196 while the PC is on. I can also set a forced manual mode that keeps it at 1.2 always.

You probably have not disabled intel speedstep and c-states. I saw the same thing before I disabled them.

 

[icraft]

I would keep them enabled. No real reason not to IMO.

 

[Darkbreeze]

Keep ISS enabled. And, I was not referring to the cache ratios in the bios. I was referring to the setting for min and max processor power state in the advanced settings of the power applet in control panel.

I would also NOT disable the C states, unless you are running a PSU that is not Haswell/Intel low power state compatible, and even then, I'd ONLY disable the C6/C7 states. No others.

Once you've determined a stable overclock or if you are running it at the stock clocks, there is no reason not to have Intel speed step enabled. You CAN run a pure "performance" power profile if you like, in the power applet of control panel, but there is no reason you cannot also set the min/max processor power states there to anything between 5% min/100% max. I like to run my chips at 10% minimum processor power state and 100% max. Setting both to 100% is fine though and should not affect sleep settings at all. C states and Intel speed step, will.

 

[Yanif]

Keep ISS enabled. And, I was not referring to the cache ratios in the bios. I was referring to the setting for min and max processor power state in the advanced settings of the power applet in control panel.

I would also NOT disable the C states, unless you are running a PSU that is not Haswell/Intel low power state compatible, and even then, I'd ONLY disable the C6/C7 states. No others.

Once you've determined a stable overclock or if you are running it at the stock clocks, there is no reason not to have Intel speed step enabled. You CAN run a pure "performance" power profile if you like, in the power applet of control panel, but there is no reason you cannot also set the min/max processor power states there to anything between 5% min/100% max. I like to run my chips at 10% minimum processor power state and 100% max. Setting both to 100% is fine though and should not affect sleep settings at all. C states and Intel speed step, will.

All good advice. Back to my original question, do you think the Vcore stays at 1.247v even I manually put the computer in sleep mode?

 

[icraft]

If you've disabled all the c-states, probably yes.

 

[Yanif]

I would keep them enabled. No real reason not to IMO.

Although my settings passed all stress tests, in real world I am experiencing a lot of BSOD, freeze, or reboot. It is very strange. It is said that disabling these features will make the system more stable. http://overclocking.guide/asus-z97-pro-gamer/

I have same Mobo and CPU.

 

[Darkbreeze]

Are you overclocking? If so, then it's not the C-states making your system unstable. It's probably your voltage settings. We need to know what you have everything set at. Core voltage, load line calibration, multi, uncore, etc.

Personally, I'd recommend returning EVERYTHING to stock settings and starting over. Use these as a guide and do not turn off the C-states unless you do not have a Haswell compliant PSU, and then only turn off C6 and C7. Intel speed step you can turn off until you've determined the overclock is stable, and then I'd turn it back on.

http://www.overclock.net/t/91/ultimate-overclocking-guide


http://www.overclock.net/t/1411077/haswell-overclocking-guide-with-statistics


http://www.tomshardware.com/forum/id-1808604/intel-temperature-guide.html

 

[Yanif]

Are you overclocking? If so, then it's not the C-states making your system unstable. It's probably your voltage settings. We need to know what you have everything set at. Core voltage, load line calibration, multi, uncore, etc.

Personally, I'd recommend returning EVERYTHING to stock settings and starting over. Use these as a guide and do not turn off the C-states unless you do not have a Haswell compliant PSU, and then only turn off C6 and C7. Intel speed step you can turn off until you've determined the overclock is stable, and then I'd turn it back on.

http://www.overclock.net/t/91/ultimate-overclocking-guide


http://www.overclock.net/t/1411077/haswell-overclocking-guide-with-statistics


http://www.tomshardware.com/forum/id-1808604/intel-temperature-guide.html

Yes, I am overclocking. Thanks for the link. It'll take sometime for me to go through all posts. Before that, here is the settings I am using right now: Vcore fixed at 1.247v and multiplier fixed at 47x, Vccin fixed at 1.647v, cashe voltage fixed at 1.15v and both min and max ratio set at 40, turned off HT, 8 GB RAM at 1600MHz, set at 1.5v. I pretty much copied the settings in that Overclocking.Guide article.

The thing puzzles me most is that this setting passed all the stress tests I ran (aida64 1h, prime95 v26.6 and v28, memtest86 v6.0.1, which is the most demanding one), but it is not stable in real world. It's hard to believe that the real world multi-application environment could be more demanding than stress tests.

 

[icraft]

1.247v and 1.647v for 4.7Ghz is very very low IMO. Like VERY.
I need 1.3v to manage 4.3Ghz, and while every chip is different I doubt most chips will do that clock at that voltage.
I would reset everything to stock, keep hyperthreading on, set voltage to 1.25v, and input voltage to 1.8 or maybe 1.9v. Watch temps though. After that raise the core multiplier slowly but ignore cache clock as it's near useless and destabilizes the OC.

 

[Yanif]

1.247v and 1.647v for 4.7Ghz is very very low IMO. Like VERY.
I need 1.3v to manage 4.3Ghz, and while every chip is different I doubt most chips will do that clock at that voltage.
I would reset everything to stock, keep hyperthreading on, set voltage to 1.25v, and input voltage to 1.8 or maybe 1.9v. Watch temps though. After that raise the core multiplier slowly but ignore cache clock as it's near useless and destabilizes the OC.

Is your cpu i7-4790k? The stock turbo is 4.4 GHz and you should get to that very easily at 1.3v.
My overclock voltage is low because I turned off HT. The reason I do that is because the old game I run does not benefit from it. HT will make it run worse.

 

[Darkbreeze]

That's a matter of opinion. I've NEVER seen HT cause issues on any game. Just because the game itself doesn't benefit from HT, doesn't mean other windows processes that are in fact still trying to do their thing while you game, don't benefit from it. But whatever, I won't argue for or against that other than to say that I don't believe it's necessary nor beneficial.

Also, it doesn't matter whether HT is on or off, that has no affect on how much voltage is required to stabilize on a core by core basis. HT really has little to no effect on how much voltage is needed although it DOES have an effect on thermal response. Keeping the overall temps cooler is the only reason I can see for disabling HT.

1.25-1.3v is pretty much average for a 4.5Ghz overclock on a 4790k, so a 4.7Ghz overclock is likely to need more than that depending on the characteristics of each individual chip. Too low of voltage is almost certainly the one and only reason you are getting errors and freezes/blue screens. If you cannot increase the voltage enough to get the chip stable then I'd suggest you consider dropping down to 4.6 or 4.5Ghz and trying to get stable there. Not every chip is going to be able to achieve higher overclocks. Silicone lottery was coined for a reason.

 

[Pinhedd]

I have set Vcore of my i7-4790k on manual mode in BIOS, meaning the cpu core is fed a constant voltage of 1.247v on 24/7 basis. I just wonder what the Vcore will be if the computer goes to sleep. Is it zero? same as shutting it down? or still 1.247v?

Hi,

When a computer is put into standby mode, what remains powered, and how much power is drawn, depends on the mode that it is put into.

In S1 standby mode, the CPU is halted but remains powered on. Other devices may be powered down if configured to do so. Due to the nature of CMOS circuitry, a halted microprocessor draws very little power. Some current will leak, so it will not be zero.

In S2 standby mode, the CPU is powered off but the memory remains powered on. The memory controller must periodically refresh the memory, so it cannot be completely powered down.

In S3 standby mode, also known as sleep mode, the CPU is powered off and the memory is placed into self-refresh, requiring no intervention from its controller. All other devices are in minimal power state and the PSU stops providing power on most rails. Devices that require power in standby (such as the memory) should draw it from the standardized 5Vsb rail. This is the common "sleep mode".

In S4 standby mode, also known as hybernation mode, the CPU and memory are both powered off and the contents of the memory are written to non-volatile secondary storage, typically a hard disk drive. All devices are in the lowest possible power state; some devices, such as network cards and keyboards, may retain power for wakeup purposes if configured.

 

[Darkbreeze]

And that ^^^ is all she wrote on that subject.

 

[Yanif]

That's a matter of opinion. I've NEVER seen HT cause issues on any game. Just because the game itself doesn't benefit from HT, doesn't mean other windows processes that are in fact still trying to do their thing while you game, don't benefit from it. But whatever, I won't argue for or against that other than to say that I don't believe it's necessary nor beneficial.

Also, it doesn't matter whether HT is on or off, that has no affect on how much voltage is required to stabilize on a core by core basis. HT really has little to no effect on how much voltage is needed although it DOES have an effect on thermal response. Keeping the overall temps cooler is the only reason I can see for disabling HT.

1.25-1.3v is pretty much average for a 4.5Ghz overclock on a 4790k, so a 4.7Ghz overclock is likely to need more than that depending on the characteristics of each individual chip. Too low of voltage is almost certainly the one and only reason you are getting errors and freezes/blue screens. If you cannot increase the voltage enough to get the chip stable then I'd suggest you consider dropping down to 4.6 or 4.5Ghz and trying to get stable there. Not every chip is going to be able to achieve higher overclocks. Silicone lottery was coined for a reason.

Wow, thanks so much for your posts. All you said directly addressed a lot of my questions/concerns. I am not a computer guy in any sense. I just play the game called Microsoft Flight Simulator X. In the simmer community, it is widely believed that HT is not a good thing for this game. An addon developer called Hifisimtech has documented that HT causes the famous 10-min freeze, so they insist to set an affinitymask value to turnoff HT in aircraft configuration file to run their program. At least that is my understanding.

Maybe I'll enable HT and lef .cfg file to manage HT so other processes can benefit from HT. I have my eyes set on eventual 4.9GHz OC. I thought turning off HT will give me more headroom, but it looks like I will bump to the Vcore ceiling first according to what you have said.