C States, EITC, LLC, overclocking.

[mango123]

I am hoping I can get some multiple inputs on some variations in information I've found in different guides and peoples posts regarding LLC and most importantly the Cstates settings in my BIOS for overclocking the Ivy Bridge on the z77 platform.

System is P8Z77-V LK running a i5 3570k. Corsair Gseries 700W PSU. Hyper 212 Evo Air cooler.

I have seen varying information that sometimes conflicts about what I want to set Cstates as, C1E vs C3-C6 reporting, and LLC settings at when I am overclocking.

As I understand it, stock settings have EIST and all Cstates enabled. They also do not use LLC from what I understand and the EIST does all the voltage dropping and raising from idle by CPUVIN request.

I have cycled through various groups of settings, 4.1-4.6, Cstates on and off, PLL overvolt on enable and disable, and sometimes auto.

Obviously when I crank my clock to 4.6, and leave everything on auto, my board is giving my Proc a whopping 1.51 Volts.... Too high obviously, temps rocket to 90 immediately. So that is a no go.

Currently I have Offset mode enabled with something like a .8(+) modifier and everything else on auto, with EIST and Cstates all enabled. I have VT and Spread and EPU disabled. And I also have Phase mode set to optimal.

Prime ran for 10 hrs stable, 81c max(package temp, cores are all around 60-70), at 4.4 ghz with a vcore of 1.28-1.29 at full load, dropping to average of .95 V at idle.

This is much better than when I had Cstates disabled, I had rare crashing in games and it didn't want to sit stable at less than 1.33-1.39

I am looking for input as far as to exactly HOW I want my LLC set and Cstates.... depending on where I look people say leave C1E ON, disable the rest, Leave EIST on, Turn EIST off, etc...
It seems everyone has a different idea of how to get their OC running right.

I'm wondering what the advantages and disadvantages of running these different settings(Cstates, LLC, PLL, and EIST) are in regards to stability, performance, and longevity of the system.
I am personally comfortable pushing it to the edge and modifying things obviously, but I do not want a lump of silicone in 6 months.

I am looking for the most stable, well performing overclock that I can manage. And water is not really an option, although my case would support it.

 

[pantsaregood]

People traditionally disable power savings because they used to affect voltages and could actually prevent overclocking in the past. This isn't the case anymore. C1E and EIST should absolutely be on. The others shouldn't affect stability, but they don't affect power consumption as much.

LLC is used to counter vdroop. You've probably noticed what your BIOS reports your vcore as is higher than Windows reports it. LLC attempts to equalize this.

PLL overvoltage is a feature on most 1155 boards. Turn it on. Otherwise, try to get your CPU to hit 1.3v after vdroop. From there, get the multiplier as high as you can.

 

[Yuriman]

This guide is pretty good at explaining why certain settings should or shouldn't be disabled.

C3/C6 and package C states will sometimes cause BSODs when overclocked with offset mode - they're ok to have on if you use fixed-voltage overclocking (which I don't recommend).

So heres your 2 options:
Offset Mode: Your CPU will use VERY LITTLE voltage and speed when idling, ANYTIME you idle. (Even browsing can be considered idling.)
Enhanced Halt State (C1E): Enabled
CPU C3 State Support: Disabled
CPU C6 State Support: Disabled
Package C State Support: Disabled

Fixed Mode: Your CPU will run full voltage and speed all the time, even when idling.
Enhanced Halt State (C1E): Enabled
CPU C3 State Support: Enabled
CPU C6 State Support: Enabled
Package C State Support: Auto

Which one is better?
Neither is "better". The first one will save you power and money, the second one will ensure you have 100% CPU power all the time. Some choose the 2nd option because they don't care about the electric bill and they like to have the best stability and power they can have. If, like me, you choose the 1st option, you will not be penalized.

Don't forget that each one can still use Sleep / Hibernate both of which will reduce the PC power usage to almost zero.

^ I ran a Q6600 without any C-states enabled for almost 5 years (highly overclocked) and it's still running fine. However, I'd recommend overclocking with offset mode and enabling them for the sake of your power bill.

Internal PLL overvoltage is useful on some chips for high overclocks (ie above 4.5ghz) but is known to sometimes cause issues with waking from sleep. My chip runs into thermal limitations before I need iPLL overvoltage but YMMV.

"iPLL overvoltage" is not to be confused with "PLL voltage". They're different things. Some have found that undervolting PLL results in lower temperatures. My PLL is set to 1.58v which is the lowest my board allows, down from stock of around 1.85v, and I have no issues.

VT is probably fine to leave on, I've never read anything about it causing problems.

__________________________
EDIT:
As for LLC, it's a matter of preference. LLC compensates for the vdroop that naturally occurs when you load your chip.

In a hypothetical scenario where you're using fixed voltage to overclock with LLC disabled, let's say you pick 1.30v as your voltage. When you load your chip up partially, your voltage may drop to, say, 1.275v. At full load it may drop to 1.250v and you'll crash because you need more than 1.250v at full load. As a result, you would need to increase your voltage to 1.325v, so it droops down to 1.275v under load. The downside to running without LLC? Your idle and partial load voltages will be higher.

In a scenario where you have EIST and C-states enabled, when your chip jumps from idle (1.6ghz) up to full clocks, the voltage will temporarily go up to the hypothetical 1.325v before drooping back down 1.275v. With LLC enabled you can avoid this voltage spike.

HOWEVER, LLC is not a perfect technology. What I found was that with LLC enabled at the highest setting, I actually had to increase my full-load voltage a little over the voltage I needed with LLC disabled or I'd BSOD. Interestingly, the BSODs typically happened when changing frequencies. IE, I'd Prime my system for 24 hours and it would pass, I'd close Prime and open it up again and BAM, BSOD.

For comparison, here are some hypothetical lowest-stable-voltages:

LLC disabled:
Partial load: 1.325v
Full load: 1.275v

LLC enabled max:
Partial load: 1.285v
Full load: 1.285v

I'm inclined to believe that with LLC enabled at a partial setting I could probably get the best of both worlds.

 

[rgallant]

just saying what I ended up with [3770K]

-only EIST on [win7] ,
-all the C STATES off[intel no adjustments]

-offset mode +xxx and LLC 75% to give me 1.3v ish @ 4.6 under prime95 load for now .

-I did not like the swinging from x16 to x46- idiot programers went nuts on the downclocking to save a few micro watts. SHOULD only downclock after a period of time ,yes upclock asap but not the down clocking every micro sec.-why not have a profile for a desk top ,the idiot more than likely got a bonus programing win7 to downclock so quickly saving lappers 1 watt in a 8hr day.

SO I turned up all the win7 power management[EIST] to 100% ,giving me a 3.5 [from 1.6] w/1.2 v ish idle [offset does this] and a 4.6 load clock .at least this way I can running some benches like AS-SSD @ 3.5 not 1.6. and going to 4.6 from 3.5 is quicker than 1.6 to 4.6 IMO.

-still swings up and down but only between 3.5 and 4.6 , just moving my mouse around typing this 3.5,3.6,3.5,3.7,3.8,3.5,4.1,3.5, I can watch it with core temps on the g15 lcd and that is time polled numbers so the swings even more than what I can see. again idiots.

but the system is stable per your question with EIST on.

 

[pantsaregood]

There is no reason for your CPU to NOT downclock when it isn't doing anything.

 

[mango123]

HELP!!! HELP!!!!

I have developed this issue where after playing games for an hour or so, my entire computer began stuttering, micro stuttering... BF3 still rendering @ 60fps but would hiccup and not even register the frame loss, streaming audio i had going would glitch out... the whole computer even the mouse would micro hitch suddenly...

SO i read that I may need a little more voltage, so I rebooted and gave it a bump, and the problem has persisted.... WTF IS GOING ON??!?!

I'm very irritated and worried, can someone please help me get to the bottom of this?

I should mention that 7970 that I have is overclocked as well.

 

[Yuriman]

Drop back to stock on both the video card and CPU. Does it still happen?

If so, I'm going to bet it's software.

 

[Ed1]

Sounds like something it overheating and maybe throttling . As posted above check temps and try backing down a bit on OC (I would look at vid first if your OC it further than manufacture bought OC's .

 

[rgallant]

" streaming audio i had going would glitch "
if nothing else works
try deleting sound drivers , reinstall set up and set up windows sound settings
-chance's are you have tons of sound devices if you have not set up a windows default sound device.
-right click speaker icon on task bar ,click play back devices to view.

-not sure for amd but with nv , windows can see all the hdmi hardware on the gpu and can set one of those to default and not your REAL sound device.
http://www.evga.com/forums/tm.aspx?m=586183 ,if you have more play back devices than you should have - see post#26 to remove the HDMI gpu ones in device manager.
-I have 2 cards so I would have many in there if I didn't disable them.

 

[mango123]

I do not believe it is temperature... Sitting good at cpu temps and gpu temps.
7970 is running at like 1150/1750 @ 1.225

 

[mango123]

I will repeat that my setup is absolutrly not overheating... And when the issue starts, it persists even when I close down all the intensive programs and just glide the mouse, it is stuttering still.
What do you guys mean software?
Pleaaase help me get to the bottom of this.

 

[Yuriman]

The only way to troubleshoot something is to try to isolate the problem. If you reset your system back to defaults, you can rule out that it's any of your hardware changes.

I've had instances where Chrome caused this due to excessive cpu/memory usage for instance. Could be any background service really. Check task manager.

 

[mango123]

And by glitch I mean the audio would grind to a halt and repeat whatever was playing over and then continue.... The mouse would stop moving.... The screen would freeze, the system would literally just fart repeatedly for a millisecond every 2 seconds or so. Anyone know or see what I'm experiencing? Maybe I should make a seperate thread?

 

[Yuriman]

1. Have you reset to bios defaults / reset to stock speeds?

2. Have you checked task manager to make sure nothing is eating up CPU/RAM?

3. Have you checked CPU-Z to ensure your CPU isn't downclocking?

 

[mango123]

No have not yet, I'm in class... Looking for.input so I can tackle this as soon as I go home.

 

[mango123]

Drop back to stock on both the video card and CPU. Does it still happen?

If so, I'm going to bet it's software.

It has not happened with this system with any sort of stock settings. I would assume safely therefore that it is not the actual hardware, but some settings for my overclock, or some variation thereof.

And just so long as everyone understands, this problem is not just in specific applications, it is system wide... my entire system hitches and hiccups... I don't believe it's throttling or "slowing down" it's almost as though it literally STOPS doing eveything for a second... hence the mouse freezing, all animation stopping, and the repeating audio bytes.

 

[pantsaregood]

That sounds like either a RAM problem or some issue with DPC latency.

 

[mango123]

what is dpc latency?

 

[RussianSensation]

You should reset all CPU and GPU clocks to stock and set BIOS to load optimal defaults or similar setting. Then see if the stuttering and mouse freezing went away.

You need to make sure your CPU and motherboard and RAM are all stable first to isolate that GPU is not the problem. Run LinX or small-ftt Prime95 test 12 hours and download MemTest86+ to make a bootable USB so you can test your RAM.

You can download this ISO and burn the Image to a CD. It has a free MemTest86+ program in there. You should test the memory for at least 10 passes to make sure memory is not a problem at stock speeds. To use MemTest86+, you'd boot off the CD Rom as the primary device.

After you isolate that memory is not the problem, run Prime95 small-ftt or LinX as I said. Once you confirm that the CPU is stable, go back to your current overclock with all power saving features disable for now and test it again with Prime95 small-ftt or LinX. We want to make sure it's stable. Once you confirm this state is stable, enable the power saving features and enable LLC. The CPU could become unstable if you are putting in 0.95V into the CPU but it's operating at 4400mhz on the desktop in idle. This would happen is your EIST/Speedstep is disabled. That's why you have to enable them or you'd have to put in more voltage to be idling at 4.4ghz.

If your system passes Prime95 already, it just sounds like you need a bit more voltage with LLC. This is normal.

 

[felang]

This guide is pretty good at explaining why certain settings should or shouldn't be disabled.

+1 for that guide

 

[WhoBeDaPlaya]

Careful if you're doing offset OCing with negative offsets. When that gets applied to a chip's idle VID, you can quickly lock-up even though you passed IBT/Prime95.