Help with PLL & VTT 3570K

[Genesius]

Hi,
Im new here and new to overclocking. Im pretty sure ive got a decent chip. I cant get the 3560k to 4.5 using 1.14 totally stable and i can run it at 1.12 but it fails one of my tests.


Heats not an issue as ive run prime95 for 12 hours and it was fine at 1.14.

At 1.12 i can run intel burn test on standard for 20 cycles and also aida64 but if i run OCCT at 1.12 it fails after 10 mins.


Now go easy on me here because im new to this. I think i can get it to pass all tests at 1.12 by adjusting the PLL and the VTT.

Some people would say its stable enough but if its not as stable as stock then its not stable enough.


My question is
Ive read about what PLL & VTT ARE but i cant work out what they DO.
Do i need more or less? what effects will that have?
What is load line calibration and what effects does changing it have?
Why not have it on max all the time?




Oh as a side note i managed to get to 5ghz at 1.4v at 1.3 i got BSOD so jumped straight to 1.4. I managed to run geekbench but then it crashed so i think i can get to 5 if i learn more about the things above.

Im looking for a 24/7 overclock of about 4.7 if i can keep the voltage down and maybe a 4.9 gaming overclock - what do you think?


Thanks

no one?

 

[Mark3Max]

First off , Welcome to the forum.
There are quite a few posts on overclocking here , If you read the post at the very top of this page from Master&Puppet it might answer your questions. He goes into alot of detail on his experience with overclocking a i7 3770k.

 

[Genesius]

Thank you.

I actually have M&P's threads favorited. Both of them. However all I know so far is that Load Line Calibration lowers the fluctuation of the Vcore under load but increasing the value and reducing the tolerance keeps volts higher which increases heat and can cause the vcore to spike over the set threshold.

I know PLL is Phase Lock Loop but don't now what it is or what affects it has.

Same with VTT, I'm sure, I read that it supplies volts to the cache but I'm new to this so I don't know what that does? Do I need to increase it as I increase the vcore?

I have searched and I have read but these seem to be a grey area. My temps are fine I just want better stability. What I want is the lowest temps and volts and the highest multiplier for a stable overclock. I've got the temps sorted, I seem to have a reasonable chip, so I just want to learn more so I can get where I want to be.

(I know what a cache is but don't know what relationship the VTT has to it)

update 28-01-2013/
Ok so im sitting writing this at 5ghz and 1.38v, so thats nice.

Anyway, i think i can get the volts dowb just need to play about more and get my fan controller installed because the H100's fan curve is a joke!

Also, i think that VTT is to do with the memory controller and cache???? so i dont think i need to touch this at all.

Can someone please correct me or let me know if im on the right track or talking utter ****

thanks

 

[kilobravo]

You only need to play with vtt if the system is unstable.It will only add heat when you increase volts.
5ghz at 1.38v,thats a golden chip you have there.

 

[tinytomlogan]

VTT is indeem memory. You dont need to touch it till you get above 1866

Remember auto means the board sets it itself this means it can & will overvolt it.....

Too much on the VTT will kill your cpu, auto isnt always safer when pushing the overclocks

 

[iBeInspire]

Don't even bother playing with anything, if it's stable @5ghz @1.38, you really don't need more mate, some people are struggling to get 4.6ghz at those volts...

 

[Master&Puppet]

As Kilo said - you shouldn't need to touch anything RAM related given that you are running a set of 1600MHz DIMMs at stock there won't be much load on the memory controller at all.

The PLL is the kind of voltage that you only worry about right at the end of your tweaking. Chances are that for an everyday overclock the auto setting supplies more than needed - you only tweak it right at the end of the whole process to reduce load temperatures by a few degrees. Often you can drop it significantly for a sub 5GHz overclock to somewhere around 1.5-1.7v (the stock is 1.80-1.9v). Most people don't bother adjusting it because for 24/7 overclocks it has very little effect.

Before you worry about doing any of that I'd suggest that you make the basics as solid as you can. That means setting up the mobo properly to limit power saving options and create a stable work place before overclocking on just the CPU multiplier and the vcore - the aim here is to touch as little as possible and therefore limit the variables to a few as possible. Adding in other voltages which have very little to add to stability can only cause confusion for very little gain! Posting screen shots of your BIOS will help us give you tips.

My biggest tip for you at this stage would be aimed at fine-tuning your stress testing methods. There are different levels of stability (as you have found out by passing IBT but failing OCCT). Hopefully you really do have a golden chip but to make sure you are truly stable I'd suggest the following:

1. To get the overclock into the right ball park use Intel Burn Test and run 10 times on very high stress setting. Make sure you have a recent version which uses the avx instruction set (I'm using v2.53). You are looking for 2 things here:
a) Your priority is that no core or CPU temperature exceeds 85C. Given the cold weather at the moment you may wish to set that limit to 80C which allows for a warmer environment during the summer.
b) That the PC successfully completes the test!

2. Run Prime95 with avx instructions (I'm currently using v27.9). You should leave it running for 24 hours or more to create something that is rock solid. You'll find that this test is more demanding and will require ~0.02v more than what you needed to pass IBT on very high. Prime95 is an endless task - i.e. you cannot complete it but 24 hours is a great measure of stability. Once 24 hours has gone and you return to your PC you should be presented with the same screen as when you left - i.e. Prime95 still working across all cores and no boxes should say "worker error".

If your CPU passes all that at 5GHz on 1.38v then sacrifice a virgin to the silicone gods because holy cow you are in heaven.

LLC is a tool we use to control voltage. When you mentioned 5GHz @ 1.38 that doesn't mean the CPU is running on 1.38v. That's more of a upper limit it doesn't want to exceed. You'll find that it probably idles around 1.37v and when it works under load it will be significantly less than that and this mechanism is known as vDroop. LLC reduces the allowed amount of vDroop which means that you can set a lower voltage figure in BIOS, after all we don't like too many volts going through even at idle when the total power draw is low regardless of the voltage. It can be worth playing around with the strength of the LLC - sometimes you can get better temperatures at load with a slightly lower LLC setting even if the idle voltage is higher.

Ultimately playing with the PLL and LLC settings will probably do very little to net you a bigger overclock but may save 5C or so under load. They are both tweaks which everyday overclockers really don't need to bother with. I'd suggest picking a relatively high LLC setting (it doesn't have to be the most extreme one) and just leave the PLL on auto.

Hope that helps!

 

[Genesius]

Wow, firstly i just want to say thank you to everyone for sharing your knowledge and taking the time to post.

Im currently waiting for a fan controller as the fans on the H100 never seem to hit 100%. i ordered 2 more of the H100 fans and have them in push pull. I know a lot of people swap the fans out for quieter fans but so far nothing has beaten them in terms of tempurature and i use a headset to game.
ive installed the fans so they're now in push pull but it makes no difference to the temps. The H100 adjusts the fan speed based ont he water temp and not the cpu temp so my 4 fans just spin slower and keep the water temp the same.

Waiting on Bitfenix Recon so i can get the temps down.

I will take some bios screen shots.

i decided to mess around last night and got the chip to boot at 5.1ghz and put 1.45 in as a starting point. it booted but soon crashed. temps were heading up to 95 though so i quickly stopped messing around with 5.1!

ive moved away from 5ghz until i can get the fans to work 100% but im currently stable (i think) at 4.7ghz with 1.250v. 1.200 causes WHEA errors and crashes.

so far i tested 4.7 with 2hrs of max OCCT, Intel burn test for 20 runs on high.
will run aida and a few more tests before i say its properly stable.

So now im at 4.7 and 1.250v what other settings can i use to bring down tempuratures? Or is that it and i should just say thats 4.7 done and go back to fiddling around and getting 5 stable?

@M&P - you said about disabling all the power saving features but id like to try and keep them on. I have done all of my overclocking on the Turbo feature so at idle the cpu returns to 1600mhz. during testing though i have 'High Performance' on under Windows so it always sits at the turbo setting and doesnt drop from 4700.

OK so i've been trying to get my 4.7 stable as that will probably be my 24/7 OC, however im still going to push for 5ghz or more stable if i can.

Im limited by temperature as im running a H100.

So 4.7 temps - please bare in mind that the H100s fans are being controlled by the H100 and not the seperate controller so i will post again once my Bitfenix recon is with me.

So....
Max temps

IBT Very high 40 passes
77 87 82 81

Aida 64
70 77 74 72

OCCT Large data set
65 71 67 65

Prime is still running but so far

Prime95
69 77 73 71

i think once i can actually get the fans to go on full over 70 degrees then ill be able to keep the temps down better.

So what advice from here on my 4.7 OC?

 

[Master&Puppet]

Well those temps look good. Getting better fans and a fan controller won't make much difference to them though - the die on Ivy Bridge is so small that there a comes a point where more aftermarket cooling makes no difference (the chip is so small it can't rid itself of the heat and aftermarket cooling can't get rid of heat it is never given).

If it passes more than 24hrs of blended prime then I'd call it stable. 4.7 @ 1.25 still?

I personally run my everyday overclocks with the turbo off but leave C1E on. It still allows windows to rest the CPU from 4.7GHz to 1.6GHz (I'm clocked at 4.7 too) - you just don't get the control of steps like you would with EIST.

 

[Genesius]

Hi M&P.

'I personally run my everyday overclocks with the turbo off but leave C1E on. It still allows windows to rest the CPU from 4.7GHz to 1.6GHz (I'm clocked at 4.7 too) - you just don't get the control of steps like you would with EIST.'

Whats the advantage to doing this as opposed to what i currently have?

Yeah im still at 4.7. i tried 1.250v with the LLC set to medium but that caused too many errors. I went back to 1.255 LLC on auto and ran the small packet test on P95 for 24 hours and that showed 2 WHEA core processor errors. I know its only 2 but i am currently running 1.255v with LLC to high to see if i get less than 2 errors. If i have to go to 1.26 then i will.

ive got some pictures here of my bios like you said.

Any idea why my Vcore isnt dropping when the cpu is idling at 1600? it just stays at 1.25? I thought it would drop back as i have all the energy saving stuff (technical) on.

once 4.7 is stable im still going to play around with 5ghz.

Temps at 4.7 are as high as i want to go on a 24/7 OC as the pc is crammed in a corner with poor air circulation, but when im playing about (5GHz)with it i move it so the temps drop 5-6 degrees.

(Apologies if i have added the photos to this post incorrectly - please advise the correct way if i have)