Haswell undervolting

[Snorlaxxx]

Hey everybody...

I'm new to overclocking and have read many guides and tutorials. My first attempt was via ASUS AI Suite III with the EZ Overclock at 4.2. I tought that would be a good start, since I'm only running a heatsink for now. (Arctic Freezer 13 Pro)
Wanted to do some testing to figure out what sort of watercooling I should get / need.

However... after the AI Suite did her thing and everything worked fine, temps in AI Suite @50C, I didn't worry anymore and continued working at some videos in PremierePro. All of a sudden I got a bluescreen. Restart --> bluescreen again. So I undid the OC and did some more CPU testing with AIDA64, CPU-Z, CoreTemp and some video encoding:


Encoding (1 hour)
83 - 83 - 82 - 78 CoreTemps @ 1.168V - 1.184V max

AIDA StressTest (1 Minute)
93 - 90 - 91 - 83 CoreTemps @ 1.284V max (wtf?)


I had CPU-Z open all day and my max voltage seems to be 1.168V - 1.184V , jumps up and down.

So I figuerd that I got the bluescreen due to too high temps. They had to be over ninethousand, if I'm getting 90C @ stock.
My guess is, that due to the "AUTO" settings the CPU draw as much power as it thought it needed, which could have been way over 1.3V and therefore the high temps.

Now...

I have two ideas.
Either set the VCore at my maximum stock voltage of 1.184V and raise the clock till it is unstable to figure out what clock I can run with that voltage without generating more heat. So same temps, but higher clock.

...or...

to look for the lowest possible VCore to run at stock speed and minimizing temps.


I would try the latter one, because I'm not comfortable with the 80+ °C I get when I'm encoding / rendering, which often times can go on for hours or even days.

Seeing that some people are getting 4.6Ghz @ 1.2X volts, I thought my stock 1.184V had to be waaaaay too much and are only that high, as mentioned above, because the CPU thinks it needs that voltage.
I'm sure I can lower that and "undervolt" the CPU.

So I wanted to try setting a manual VCore in the UEFI as "adaptive mode". Instead "Auto" something around 1.1V as a start and work from there.

My problem is I don't know how to set the adaptive VCore or rather I got confused with the whole "offset" settings and how they work. Do I set the difference from the number in grey (1.025V) to my desired voltage (0.075V) or do I enter 1.100V?

Please explain to me how that works. All trustworthy guides I could find on youtube said adaptive is the way to go, but for demonstration they did the OC in manual mode 😞


If my whole idea of undervolting the CPU should be a misbelief, feel free to give me some advice regarding my other idea of raising the clock only.

Thanks 🙂



//EDIT:
Totally forgot to post my specs 😄
Maximus VI Hero // i7 4770k // 32GB G.Skill 1866 RAM
If you need to know something specific please ask.

[HiVizMan]

May I ask which CPUz you are using? Not all the 1.64 versions are reading the correct voltage.

[Snorlaxxx]

The ROG Edition. Version 1.60.

I installed 1.64 now, but didn't do all the tests yet.


//EDIT:
A quick Intel PDT run showed the same max VCore of 1.168V

[HiVizMan]

The ROG version does read the voltages.

Thanks just wanted to make sure you had the right information.

[Snorlaxxx]

As I see it, adaptive just raises the voltage for the turbo speed and leaves the rest (idle) alone. Thats nice and well, but if I raise the adaptive voltage I raise the temps as well and the result would be the normal way of overclocking.
For my purpose of finding the lowest voltage for stock clock I need a way to set the voltage at a fixed number, like manual. Under which setting in the UEFI do I do it? And I know that even at a fixed adaptive voltage the voltage can spike a little with programs that use AVX. Thats maybe what I am seeing with the 1.184V instead of the usual 1.168V i get and thats fine. If I lower the voltage it doesn't matter anyway.

[Praz]

Snorlaxxx wrote:
As I see it, adaptive just raises the voltage for the turbo speed and leaves the rest (idle) alone. Thats nice and well, but if I raise the adaptive voltage I raise the temps as well and the result would be the normal way of overclocking.
For my purpose of finding the lowest voltage for stock clock I need a way to set the voltage at a fixed number, like manual. Under which setting in the UEFI do I do it? And I know that even at a fixed adaptive voltage the voltage can spike a little with programs that use AVX. Thats maybe what I am seeing with the 1.184V instead of the usual 1.168V i get and thats fine. If I lower the voltage it doesn't matter anyway.

I'm a bit confused as to what it is you want to achieve. If you want the lowest voltages possible throughout the stock CPU frequencies use the offset mode. Change the offset to negative and type in the amount of voltage you wish to reduce the stock voltage by across the stock multiplier range. If your goal is the same as above while also using overclocked multipliers use the adaptive mode. Use the offset under adaptive as noted above for the stock multipliers. For the overclocked multipliers type in the actual voltage value needed for stability in the Adaptive Turbo Boost field. Please note this method can cause stability issues during the transition point of stock to overclocked frequencies. Using a negative offset can also be problematic if the value is chosen for stability at the highest CPU frequency only. During low load or idle conditions the voltage may be reduced to the point that stability is affected.

[Snorlaxxx]

@KPRage: I understand how offset mode and adaptive mode works. My reasoning was just off at the beginning.
For what I wanted to achieve offset mode did the trick. I will tackle adaptive mode when I get my water cooling in place and go O.C. 😄

Praz wrote:
I'm a bit confused as to what it is you want to achieve. If you want the lowest voltages possible throughout the stock CPU frequencies use the offset mode.

That's exactly what i did 🙂
First I thought I needed to reduce just the Turbo voltage, hence adaptive mode, but then I realized that for reducing voltage I could use the offset method and reduced the voltage across the board.
But thanks for your whole detailed explanation.


I made a quick & dirty "tutorial" about how I did it:

[HiVizMan]

I think the key is you finding what voltage is the minimum for your needs, and I would assume that the traditional manual method is the way for you.

Am I correct that you are asking where is the manual method?

[Snorlaxxx]

LoL. I just ran Cinebench R11.5. I did that when I bought the CPU and got a score of 8.37. Now it shows me 8.57. Maybe its normal, but I had to laugh how the undervolted CPU does a better score 😄

Max VCore is 1.104V @stock 3.9GHz - Temps 65 - 63 - 63 - 62. Now that's more to my liking for doing renders 🙂


Idle temps dropped from 40-42°C to 32-35°C.

[KPRage]

Snorlaxxx wrote:
LoL. I just ran Cinebench R11.5. I did that when I bought the CPU and got a score of 8.37. Now it shows me 8.57. Maybe its normal, but I had to laugh how the undervolted CPU does a better score 😄

Max VCore is 1.104V @stock 3.9GHz - Temps 65 - 63 - 63 - 62. Now that's more to my liking for doing renders 🙂


Idle temps dropped from 40-42°C to 32-35°C.

May be a case of CPU throttling. May be since the temps were getting high, the CPU would throttle down. Hence may be the case of reduced score..:) However, lets wait for HVM's results..:)