CPU overclock - comments wanted (i7 4790k @ 4.6GHZ)

[Grady 54]

Hello everyone,

 

I was hoping some of you might be able to comment on my recent OC - I'm mainly looking pointers on potential improvement.

 

So a quick run down of my system specs.

 

PSU: Corsair AX860

MOBO: Asus Sabertooth Z97 Mark 1

CPU: i7 4790k

GPU(1): GTX980ti

GPU(2): GTX980ti

RAM: Corsair Dominator 16GB DDR3 1866

HDD: WD Black 2TB

SSD(1): Samsung 850 Pro 256GB

SSD(2): Samsung 850 Evo 120GB

 

-------------------------------------------

 

The Overclock:- (I've opted not to change the base clock, but instead the multiplier as the 4790k is already 'unlocked').

 

• XMP - profile 1 (correct timings etc with memory)
• Base clock - remains the same

• CPU core ratio - sync all cores
• 1 core ratio limit - 46
• Min CPU cache ratio - 44
• Max CPU cache ratio - 44
• Internal PLL overvoltage - enabled
• EPU power saving mode - enabled
• CPU core voltage (manual) - 1.250
• CPU cache voltage (manual) - 1.275
• Enhanced Intel Speedstep Technology - enabled
• Turbo mode - enabled
• CPU C-states - enabled

I guess my main questions would be:-

 

1. Have I missed anything crucial?

2. Is there room for improvement?

3. Can I push to 4.7GHZ / 4.8GHZ safely, one thing I've noted from various benchmarks running 4.8 is that the voltages seem to jump considerably.

 

Notes / concerns I have:-

 

Running the 4790k stock, the core clock speed fluctuates within CPUZ, this is obviously the turbo boost and power saving functions within the BIOS and windows. However, using my OC, I no longer see any fluctuations, leaving me to believe that the power saving features are no longer working, despite having EIST and C-states enabled. Naturally, not wanting to degrade the life of my CPU any more than I need to, I don't want it working at 4.6GHZ all the time.

 

(4.6GHZ OC) Click to enlarge:-

 

(4.7GHZ OC) Click to enlarge:-

 

I gave Asus OC tuner a try for the first time today, whilst I do see the advantages for those perhaps not wanting to manually OC, the voltages it was pumping to my CPU were way OTT. Certainly not for the minimal overclock it was offering, so back to manual it was.

 

Many thanks,

 

Grady.

[martin-w 3,234]

3. Can I push to 4.7GHZ / 4.8GHZ safely, one thing I've noted from various benchmarks running 4.8 is that the voltages seem to jump considerably.

 

 

 

If your system is stable and you are happy with your performance... I wouldn't bother?

 

Overclocking in a balanced system is linear. In which case the frame rate improvement at 30 frames per second for 100MHz is a mere 0.6 or a frame per second.

 

If you can do so easily, without excessive voltage or temp, then why not. On the other hand if you are concerned even slightly about temp or voltage... no point.

[Grady 54]

If your system is stable and you are happy with your performance... I wouldn't bother?

 

Overclocking in a balanced system is linear. In which case the frame rate improvement at 30 frames per second for 100MHz is a mere 0.6 or a frame per second.

 

If you can do so easily, without excessive voltage or temp, then why not. On the other hand if you are concerned even slightly about temp or voltage... no point.

 

Many thanks for your reply Martin.

 

I certainly don't want to risk component failure for 0.6fps!

 

For the moment I am sticking with my 4.7OC (core ratio @ 47 and cache ratios @ 45) - the only concern I have is my VCORE temps are slightly on the warm side.

 

(Cooler - Corsair H100i GTX)

 

Temperatures at idle:-

 

Stock - CPU ~ 27c

Stock - VCORE ~ 34c

 

4.7OC - CPU ~ 29c

4.7OC - VCORE ~ 50c

 

That's quite a considerable jump. I consider the airflow within the case to be good and I have both assistant fans installed on the MOBO.

 

After much reading I've deduced that this seems to be a reasonable temperature, not sure if I'd agree, however short of putting the computer next to an air conditioning unit...

 

Thanks again.

 

Grady.

[Guest JustanotherPilot]

I have the 4790K overclocked to a stable 4.5ghz, to do this I used the Intel Extreme overclocking utility and downloaded a OC profile for this CPU from HWBOT.

 

I also use a coolermaster air cooler, which keeps it cool under the most testing conditions.

[jjjallen 37]

I haven't seen many systems that can go above 4.6 without complaining.  4.6 is a vg clock if your temps stay inbounds.

 

regards

jja

[TechguyMaxC 516]

Devil's Canyon (4790k & 4690k CPUs) are almost all good to 4.8GHz+ with reasonable voltage (i.e. less than 1.35V) provided adequate cooling to keep temps in check.  My 4790k does 4.8GHz with 1.34V and 5.0GHz with just over 1.4V.  I use custom water cooling and have de-lidded my chip to achieve these results.  I've recently chosen 4.8GHz for long-term stability as I've already owned the CPU for over a year now and had been running at 5.0GHz the whole time.  I don't tend to keep CPUs a long time so I usually run them full-out but I may not upgrade the system in which I have the 4790k for awhile, given its use.  

 

Bottom line: if you have the cooling and you don't need dangerous voltage, run it as high as you can within these parameters.  If 4.7 is the limit for your chip, be happy with that.  If you want to know what the limits are, keep pushing the multiplier and stress testing until you find instability, then increase the voltage until it is no longer unstable.  If the voltage and/or temperatures are outside of your comfort zone, back down the clock speed and voltage until you are where you want to be.  If you're only hitting 50C during a stress test, you're nowhere near the thermal limits of your chip, BTW (105C is the throttle point for Haswell/Haswell-E).