Question Overclocking i5 6600k

[AxelG]

Hello, i was just wondering how high you really can push the vcore when overclokcing, The chip max is 1,52 according to intell and i wondered if 1,45v is too high for 4,8Ghz on 4 cores?

When it gets a bluescreen, is that from overvoltage or undervoltage?

And when it freezes is that because the clock is too high or the voltage to low?

I have a Cooler Master EVO v2 and its sitting at 50 degrees under load at 1.4v 4,6Ghz


(I'm new to overclocking and just wanna do this for experimenting and if it works i wanna continue using it)

 

[Darkbreeze]

Freezes and blue screens could be from either, clock too high or voltage too low. Both those things can cause stability issues so either of them could be to blame. I some cases voltage too high can ALSO cause instability, but usually you'll encounter thermal issues from voltage too high before stability issues unless you are running a very good custom loop cooler, and even then really.

Here is a very good guide for overclocking on Skylake.

https://www.tweaktown.com/guides/74...e-intel-skylake-overclocking-guide/index.html


And for those who are new to overclocking in general, my guide on the basics, which you should familiarize yourself with before making further attempts, but do read and reference both guides while refining your overclock.

CPU overclocking guide and tutorial for beginners

Covering the basics If you found your way here it's likely you are looking for help with basic overclocking. Either that or you're a long time overclocker interested in seeing whether I had any eye opening insights that you may have been lacking. Rest assured, I don't. This is only intended as...

forums.tomshardware.com

 

[mdd1963]

Hello, i was just wondering how high you really can push the vcore when overclokcing, The chip max is 1,52 according to intell and i wondered if 1,45v is too high for 4,8Ghz on 4 cores?

When it gets a bluescreen, is that from overvoltage or undervoltage?

And when it freezes is that because the clock is too high or the voltage to low?

I have a Cooler Master EVO v2 and its sitting at 50 degrees under load at 1.4v 4,6Ghz


ps(I'm new to overclocking and just wanna do this for experimenting and if it works i wanna continue using it)

50C under load at all-core 4.6 GHz? (Those temps seem low enough that I am skeptical...; see what temps are with CPU-Z/bench/stress CPU running for 10 minutes)

Alas, but with 4 cores/4 threads, chasing and even achieving the last 100 MHz is probably not going to amount to much gained FPS in gaming, anyway...

At some point at 4.6 - 4.7 GHz, temps will start rising much faster for each 100 MHz increase, especially if a +.05V core voltage tweak is needed... (My own 7700K jumped from 72C at load to 85C going from 4.7 GHz to 4.8 GHz, so, I stayed with the lower clock speed.)

 

[Darkbreeze]

At some point at 4.6 - 4.7 GHz, temps will start rising much faster for each 100 MHz increase, especially if a +.05V core voltage tweak is needed... (My own 7700K jumped from 72C at load to 85C going from 4.7 GHz to 4.8 GHz, so, I stayed with the lower clock speed.)

This is a good idea anyhow, for practically ANY overclock, if it's a piece of hardware you want to keep around for a while. Figure out where you hit a wall, tweak your settings, then drop the multi by 100mhz. It will last far longer that way because you'll encounter less electromigration and VT shift at a lower frequency plus then you can usually drop a little voltage off and still remain quite stable, while also reducing thermal response and electromigration.

 

[AxelG]

50C under load at all-core 4.6 GHz? (Those temps seem low enough that I am skeptical...; see what temps are with CPU-Z/bench/stress CPU running for 10 minutes)

I only used a part of the cpu when i tested, so i'm sorry about that, when i tested the whole cpu it got to around 61-62 degrees

 

[Zerk2012]

I only used a part of the cpu when i tested, so i'm sorry about that, when i tested the whole cpu it got to around 61-62 degrees

Skylake	All Core SSE Frequency	All Core AVX2 Frequency	BIOS Vcore	% Capable
6600K	4.50GHz	Not Tested	1.376V	100%
6600K	4.60GHz	Not Tested	1.392V	Top 91%
6600K	4.70GHz	Not Tested	1.408V	Top 70%
6600K	4.80GHz	Not Tested	1.424V	Top 38%
6600K	4.90GHz	Not Tested	1.440V	Top 14%
6600K	5.00GHz	Not Tested	1.456V	Top 2%

https://siliconlottery.com/pages/statistics

When testing you need to run a stress test using 100% of the CPU.

 

[AxelG]

Skylake	All Core SSE Frequency	All Core AVX2 Frequency	BIOS Vcore	% Capable
6600K	4.50GHz	Not Tested	1.376V	100%
6600K	4.60GHz	Not Tested	1.392V	Top 91%
6600K	4.70GHz	Not Tested	1.408V	Top 70%
6600K	4.80GHz	Not Tested	1.424V	Top 38%
6600K	4.90GHz	Not Tested	1.440V	Top 14%
6600K	5.00GHz	Not Tested	1.456V	Top 2%

https://siliconlottery.com/pages/statistics

When testing you need to run a stress test using 100% of the CPU.

this is my aida64 cpu test
https://prnt.sc/dfyTBRnpddXB

 

[Darkbreeze]

Aida64 is a waste of time. It's good for making you THINK everything is fine, and that's about it. It comes no where near TDP like Prime95, Heavyload and a few others do, so it's only good for giving you a false sense of security (As expressed to me in the distance past by Computronix, our resident Intel CPU expert and engineer) because the temps are so low.

If you want to get a REAL idea of where you are, use the test guidelines I outlined in my overclocking tutorial which I previously posted a link to.

Also as shared by Comp, you absolutely want to use a utility with a steady state workload when testing CPU thermal performance.

I'm aware of 5 utilities with steady-state workloads. In order of load level they are:

(1) Prime95 - Small FFT's (AVX options disabled OR offset configured in the BIOS for AVX)
(2) HeavyLoad - Stress CPU
(3) FurMark - CPU Burner
(4) Intel Processor Diagnostic Tool - CPU Load
(5) AIDA64 - Tools - System Stability Test - Stress CPU

AIDA64's Stress CPU fails to load any overclocked / overvolted CPU to get anywhere TDP, and is therefore useless, except for giving naive users a sense of false security because their temps are so low.

HeavyLoad is the closest alternative. Temps and watts are within 3% of Small FFT's.



Here is the quick and dirty version of my test procedure, but a more in depth procedure with additional information is available in the link I posted previously for Overclocking for beginners. There are definitely other methodologies out there but Prime95 is the one component that shouldn't change as there is still no better metric for measuring thermal compliance with realistic near-TDP steady state workloads.

Quick and dirty overview of overclocking validation procedure.

Set CPU multiplier and voltage at desired settings in BIOS. Do not use presets or automatic utilities. These will overcompensate on core and other voltages. It is much better to configure most core settings manually, and leave anything left over on auto until a later point in time if wish to come back and tweak settings such as cache (Uncore) frequency, System agent voltage, VCCIO (Internal memory controller) and memory speeds or timings (RAM) AFTER the CPU overclock is fully stable.

Save bios settings (As a new BIOS profile if your bios supports multiple profiles) and exit bios.

Boot into the Windows desktop environment. Download and install Prime95.

Download and install either HWinfo or CoreTemp.

Open HWinfo and run "Sensors only" or open CoreTemp.

Run Prime95, WITH the AVX and AVX2 options disabled in the settings menu (Or an appropriate offset for AVX configured in the BIOS) that pops up when you start up Prime95, and choose the "Small FFT test option". Run this for 15 minutes while monitoring your core/package temperatures to verify that you do not exceed the thermal specifications of your CPU.

(This should be considered to be 80°C for most generations of Intel processor with an absolute maximum acceptable range of 85°C and for current Ryzen CPUs a maximum of 80°C. For older AMD FX and Phenom series, you should use a thermal monitor that has options for "Distance to TJmax" and you want to NOT see distance to TJmax drop below 10°C distance to TJmax. Anything that is MORE than 10°C distance to TJmax is within the allowed thermal envelope.)

If your CPU passes the thermal compliance test, move on to stability.

Download and install Realbench. Run Realbench and choose the Stress test option. Choose a value from the available memory (RAM) options that is equal to approximately half of your installed memory capacity. If you have 16GB, choose 8GB. If you have 8GB, choose 4GB, etc. Click start and allow the stability test to run for 8 hours. Do not plan to use the system for ANYTHING else while it is running. It will run realistic AVX and handbrake workloads and if it passes 8 hours of testing it is probably about as stable as you can reasonably expect.

If you wish to check stability further you can run 12-24 hours of Prime95 Blend mode or Small FFT.

You do not need to simultaneously run HWinfo or CoreTemp while running Realbench as you should have already performed the thermal compliance test PLUS Realbench will show current CPU temperatures while it is running.

If you run the additional stability test using Prime95 Blend/Small FFT modes for 12-24 hours, you will WANT to also run HWinfo alongside it. Monitor HWinfo periodically to verify that no cores/threads are showing less than 100% usage. If it is, then that worker has errored out and the test should be stopped.

If you find there are errors on ANY of the stability tests including Realbench or Prime95, or any other stress testing utility, you need to make a change in the bios. This could be either dropping the multiplier to a lower factor or increasing the voltage while leaving the multiplier the same. If you change voltage or multiplier at ANY time, you need to start over again at the beginning and verify thermal compliance again.

​

 

[Karadjgne]

This is a good idea anyhow, for practically ANY overclock, if it's a piece of hardware you want to keep around for a while. Figure out where you hit a wall, tweak your settings, then drop the multi by 100mhz. It will last far longer that way because you'll encounter less electromigration and VT shift at a lower frequency plus then you can usually drop a little voltage off and still remain quite stable, while also reducing thermal response and electromigration.

That's what I did with my 3770k. Hit 5.0GHz at 1.42v, then dropped it to 4.9GHz @ 1.328v and test temps dropped from 88°C to 72°C as a result. Can't say as I saw any real fps changes either, and it sat that way for the next 6 years 24/7. There just comes a time when the cost far outweighs the benefits, and with a slim as the benifits (if any) were, any cost was too much.

Op, there's 2 different kinds of tests. Stress and temp. Decide which result you are chasing and use the right tool for that job. Using all-in-one type don't work out well because they aren't specific tests. You can't get a good temp result with a test that stresses the cpu by using different software at different levels of load designed to try and trip the cpu up. Same with trying to trip the cpu up in a test using software designed for a steady state load at 100% that results in max temps. You might hit max temps with a stress test, for a very short period, you might also trip the cpu with a temp test if the OC isn't stable, but there's no guarantee or reliable result, never know if it was a fluke hit or actual max temp.

A good OC is one that has acceptable voltages, acceptable temps and is acceptably stable, regardless of clock speeds. A bad OC is one that fails in any single one, voltages, temps or stability simply based on wanted clock speeds.