[SOLVED] Overclocking i7 4790k to 4,8 GhZ?

Dercie

Honorable
Jul 31, 2016
25
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10,530
CPU: Intel Core i5 4790K 4.0 GHz (Haswell) *4
Motherboard: ASUS Z87M-Plus mATX
Ram: A-Data 8GB (2x4GB) CL9 1600MHz XPG + Crucial 8GB (2*4096MB) CL8 1600MHz Ballistix Elite
SSD/HDD: 1TB Seagate Barracuda 7200rpm 64MB and Intel 330 Series 2.5" 120GB SSD Sata/600 MLC 25NM
GPU: 1 x Powercolor Radeon RX 590 8GB Red Dragon
PSU: Fractal Design Integra R2 650W 80+ Bronze
Chassis: Cooler Master Silencio 352
OS: Microsoft Windows 10 Pro
Monitor: ASUS VP247 @ 82 Hz

Hi,

I have successfully overclocked my i7 4790k to 4,7GhZ with Vcore 1,31 and Vccin to 1,85

However I've read several succeeding to overclock it even further, and I would love for it to run at least 4,8 GhZ, if that is possible that is with my CPU.

I have tried settings reaching from Vcore up to 1,355 GhZ and Vccin to 1,9 but the system has been unstable after stress testing.

I read somewhere that Volts more than 1,35 for 4790k is not good so I have not been pushing the volt further
 
Solution
Dercie,

No two processors are identical; each is unique in voltage tolerance, thermal behavior and overclocking potential, which is often referred to as the "silicon lottery".

Overclocking is always limited by two factors; voltage and temperature.

Since overclocked processors can run more than 50% above rated TDP, high TDP air or liquid cooling is crucial. Although "Throttle" temperature for the 4790K is 100°C, the consensus among well informed and highly experienced reviewers, system builders and expert overclockers, is that it's prudent to observe a reasonable thermal margin below Throttle temperature for ultimate stability, performance and longevity. So regardless of environmental...

stonewall89

Distinguished
Dec 5, 2010
2
0
18,510
Ok, a couple things. You posted your specs but when talking about wanting to overclock and push a 4790 past 1.35v and to try for 5Ghz you left out arguably the most important thing: what is your cooling solution? Are you running the bog standard Hyper 212, a 240 or 360 AIO, are you fully open loop cooled? If you are on air, even with something great like the Noctua D14, I would suggest not going past 1.35 and deffintely not to 1.4, and maybe just forgo trying to hit 5Ghz. Even on an AIO I would doubt your temps would be where you'd want them. When the 4790k dropped there was a decent amount of buzz about how this was the first 5Ghz i7 and whatnot. Personally I think that was a bunch of bull and random people trying to show off their E-peen claiming they could hit 5Ghz at absolutely unrealistic voltages. Its just my personal opinion "real" 5Ghz chips didn't come until later. The amount of 4790s even able to hit 5Ghz at any voltage is very low, especially if being 100% stable means anything to you and you don't want random and frequent BSoDs and always being afraid of losing game progress or doing something non game related and losing your work.

I spent the first few years tinkering with clock speeds, voltages, bus speeds, RAM timings, all the fun stuff trying to sqeak out that last 1% of performance until I eventually got tired of doing it. I will say, as good as my silicone is/was being a decent lottery winner, I was never able to hit 5Ghz-and believe me I tried. Sure, I could get my computer to post and boot into windows at 5Ghz, but it was so unstable that no one in their right mind would ever want to keep it there. At my highest, I was able to maintain a 4.85+ OC at 1.29 and a 46x cache and be 90% stable, however that wasn't solely on multiplier alone but with a bump in bus speed which is probably where that random 10% instability came from. As a side note, I could never keep my system stable if I pushed my cache beyond 46 at any voltage for either the Vcore or the cache; even if I went to 47 cache and underclocked the CPU, it was unstable. The clock I've settled with for the past many years has been 4.71 @ 1.26 and a 46x cache. That is a decent bump over the stock 4.4 and I am 100% stable and my temps are icy cool. People claiming they were hitting 4.8 at 1.25 and 5Ghz at 1.3 without ever showing proof of those speeds and moreso proof of stability at those speeds and voltages I never believed.

TL;DR

You're going to want to be on more than air cooling when talking about those vcore numbers.
A good deal of 4790s won't hit 5Ghz no matter how much voltage you pump into them.
I'm no expert or engineer or some minor celeb on Youtube, but I would not advise running a 4790 24/7 at 1.35-1.4 volts. I completely understand the feeling that our chips are getting a bit long in the tooth and wanting to sqeeze every bit of performamce out of them now more than ever, to keep up with modern releases and tide us over until computer prices become somewhat normal again. But especially during these times with everything the way it is, I wouldn't suggest going to the absolute limit. Even if theoretically you could maintain 5Ghz at 1.4 volts, you're probably going to kill that thing orders of magnitude faster than you would running it at 4.6 or 4.7 and under 1.3 volts and just deal with not having the extra 5 FPS or whatever.
 
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CompuTronix

Intel Master
Moderator
Dercie,

No two processors are identical; each is unique in voltage tolerance, thermal behavior and overclocking potential, which is often referred to as the "silicon lottery".

Overclocking is always limited by two factors; voltage and temperature.

Since overclocked processors can run more than 50% above rated TDP, high TDP air or liquid cooling is crucial. Although "Throttle" temperature for the 4790K is 100°C, the consensus among well informed and highly experienced reviewers, system builders and expert overclockers, is that it's prudent to observe a reasonable thermal margin below Throttle temperature for ultimate stability, performance and longevity. So regardless of environmental conditions, hardware configurations, software workloads or any other variables, Core temperatures above 85°C are not recommended.

Accordingly, here's the nominal operating range for Core temperature:

Core temperatures below 80°C are ideal.


PdancCI.jpg


Core temperatures increase and decrease with ambient (room) temperature, for which the International Standard for "normal" is 22°C or 72°F.
Each Microarchitecture, which is expressed in "nanometers" (nm), has a “Maximum Recommended Vcore”. For example, it’s important to point out that 22 nanometer 3rd and 4th Generation processors will NOT tolerate the higher Core voltages of other Microarchitectures.

Here's the Maximum Recommended Vcore per Microarchitecture from 14 to 65 nanometers since 2006:

qmcaTkx.jpg

We know that over time, excessive voltage and heat damages electronics, so when using manual Vcore settings in BIOS, excessive Core voltage and Core temperature can cause accelerated "Electromigration". Processors have multiple layers of hundreds of millions of microscopic nanometer scale components. Electromigration erodes fragile circuit pathways and transistor junctions which results in the degradation of overclock stability, and thus performance.

Although your initial overclock may be stable, degradation doesn't appear until later, when increasingly frequent blue-screen crashes indicate a progressive loss of stability. The more excessive the levels of voltage and heat and the longer they're sustained determines how long until transistor degradation destabilizes your overclock. Decreasing overclock and Vcore may temporarily restore stability and slow the rate of degradation. Extreme overvolting can cause degradation in minutes, but a sensible overclock remains stable for years.

Each Microarchitecture also has a "Degradation Curve". As a rule, CPUs are more susceptible to electromigration and degradation with each Die-shrink. However, the exception to the rule is 14 nanometer (nm) Microarchitecture, where advances in FinFET transistor technology have improved voltage tolerance.


Here's how the Degradation Curves correspond to Maximum Recommended Vcore for 22 nanometer 3rd and 4th Generation, which differs from 14 nanometer 5th through 10th Generation:

iQuLSzu.jpg

Degradation Curves are relative to the term “Vt (Voltage threshold) Shift” which is expressed in millivolts (mv). Users can not monitor Vt Shift. With respect to overclocking and overvolting, Vt Shift basically represents the potential for permanent loss of normal transistor performance. Excessively high Core voltage drives excessively high Power consumption and Core temperatures, all of which contribute to gradual Vt Shift over time. Core voltages that impose high Vt Shift values are not recommended.

To achieve the highest overclock, keep in mind that for your final 100 MHz increase, a corresponding increase in Core voltage of about 50 millivolts (0.050) is needed to maintain stability. If 70 millivolts (0.070) or more is needed for the next stable 100 MHz increase, it means you're attempting to overclock your processor beyond its capability. All processors reach a limit where an additional increase in Core voltage will not stabilize another 100 MHz increase in Frequency.


Here's an example of a Core Voltage / Frequency Curve:

6MNWMZw.jpg

With high-end cooling you might reach your Maximum Recommended Vcore limit before you reach the ideal Core temperature limit at 80°C. With low-end cooling you’ll reach 80°C before your Vcore limit. Regardless, whichever overclocking limit you reach first is where you should stop.

Remember to keep overclocking in perspective. For example, the difference between 4.5 and 4.6 GHz is less than 2.3%, which has no noticeable impact on overall system performance. It simply isn’t worth pushing your processor beyond recommended Core voltage and Core temperature limits just to squeeze out another 100 MHz.


If you look very closely at the third illustration, you can see that the highest you want to push your 4th Generation 22nm 4790K is about 1.325 Vcore. I would stay right where you are at 4.7GHz, declare O/C victory and enjoy your rig.

CT:sol:
 
Solution

Karadjgne

Titan
Ambassador
Vccin of 1.9 isn't a guarantee of stability or ability, having raised it from 1.8. My 3770k hit 5.0GHz stable by dropping vccin to 1.7 instead.

To achieve the most out of the cpus demands a whole lot more effort on your part other than just messing with vcore and vccin, there's Ring voltages, LLC should be no more than @ 3/4 (don't use extreme or highest setting), current power delivery needs raising, phase settings need dedication not eco savings, turbo timers, c-states and other power saving/eco settings disabled System Agent adjustments and much more besides.

Very, VERY few 4thgen hit 4.8GHz or higher, most normally they'd be voltage limited (realistic daily use) long before hitting such high speeds.

Ideally you'll not want to go much further than @ 1.2v-1.25v, regardless of what speed you think you need. V=IxR, and with voltages limited, resistances in cpus being roughly the same consistently, the largest gains will be had with I, impedance, or in English, Currant. And that's going to be totally motherboard and VRM dependent. If you don't have the phases and VRM's and VRM cooling to handle the higher currant draw well, you'll not get a stable, high OC. And that's also going to rely on the psu delivering cleanish power. A craptastic voltage output psu will never allow high OC, too erratic for stability at load.

Fps is a responsibility of the cpu. Frames are built on instructions, instructions per cycle, or IPC meaning the higher the clock, the more instructions processed, higher the fps. But raising clocks from 4.7-4.8GHz is less than a 5% gain, so roughly 2% fps gain when all is said and done. A 10fps bump to Warzone is only meaningful if you are getting much less than 60fps. Pushing upwards of 200fps, that 10fps becomes nothing more than margin of error, and you physically can't even see results.
 
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