i5 4690K @4.5GHZ @1.189v

[m6tzg6r]

My system specs can be seen in my avatar to the left.

Before today i had my CPU multiplier set to 40, and the voltage the motherboard had set automatically was 1.082-1.090v. That was at load, but went down in idle.

Today i set the multiplier to 45, and then the voltages jumped to 1.280 or so. But i knew those voltages could be lower, so i set them to 1.200, which gives me 1.189v in Windows at 4.5GHZ. Maybe they could be lower, so far no crashes, but for now 1.189v seems nice. Hell, better then that 1.280 the motherboard set itself...

Anyway my core clock drops to 800mhz when idle, but now i have the voltage manually set, it remains at 1.189v all the time. I tried to change some settings in the bios to make the voltages lower when idle, but it didn't work. So my voltages wont lower anymore when idle?

Atleast the core clock lowers, temps are low, and i would think 1.189v is safe for 24/7 operation. But i guess it would be nice if the voltage went down when i am idle. Or maybe a fluctuating voltage is not as good as having a consistent voltage?

Im pretty sure 1.189 is totally cool for a 4690K to handle.

 

[xorbe]

I found the problem with fixed voltage (w/4790k) is that if one runs Prime95 the speed drops to 3Ghz for example (of course depends on the voltage selected). I ended up with 4.5 and offset voltage -0.030 so that way brutal Prime95 only dropped to 4.3 GHz

 

[BiggieShady]

Anyway my core clock drops to 800mhz when idle, but now i have the voltage manually set, it remains at 1.189v all the time. I tried to change some settings in the bios to make the voltages lower when idle, but it didn't work. So my voltages wont lower anymore when idle?

That board Gigabyte Z97-X Gaming GT has these options in UEFI BIOS:

I suggest you set vcore to normal and vcore offset to some negative value (something from -0.02 V to -0.05 V), if it BSODs while changing power states try different load line calibration setting.
Also, depending on silicon lottery and cpu multiplier, you may not be able to undervolt at all, and have a stable system.
I had to lower my undervolt for mere 40 multiplier on my ivy bridge to completely get rid of random WHEA internal parity errors in my event log.

 

[xorbe]

A way to avoid lower clock problems:

Control Panel -> Power -> High Perf -> Change Plan -> Change Advanced -> Processor power management -> Min proc state

100% keeps the cpu spooled up at top turbo clock (at least on my Hero mobo)
95% drops to the base non-turbo
and so on, less is less idle speed, etc

Use Core Temp to monitor the mult/voltage effect of Min Proc State. With my older system, 5% vs 100% the desktop felt so much more snappy, because it was running at 800 MHz vs 4 GHz, and the desktop action was never enough to spool up the CPU so it was running 5x slower clocks ...

 

[Schmuckley]

Nah,there's something "special" with Haswell.
Not in a good way,either.
Chip like..self-throttles or something.

 

[m6tzg6r]

Yeah for now i just have the voltage constant, but the clock varies from 800-4500mhz. Also i will turn down my CPU Voltage by 0.010 everyday before i start using my system, and i will see how low i can get the voltage before it becomes unstable.

Currently running 1.179v @4.5ghz, tomorrow will bump it down to 1.169, and once it becomes unstable i will just turn it back up to make it stable again.

One thing i noticed, if i set the multiplier to 45, the bios just wacks the voltage up to 1.280v, but if i set the voltage manually, i can run it at 1.179v just fine, but by default the motherboard runs it 0.101v higher then it even needs. Probably because the motherboard is just giving it a random number that gigabyte have decided is a safe voltage that ensures stabilty at that clock speed. Meanwhile if you tune the voltage manually you can actually reduce it alot, and find exactly what your CPU needs, instead of just letting the motherboard pull some random number out of its ass.

 

[xorbe]

Currently running 1.179v @4.5ghz, tomorrow will bump it down to 1.169, and once it becomes unstable i will just turn it back up to make it stable again

Just fyi I noted that @ 4.5 1.160v crashes and 1.170v didn't (for like 15 minutes). I'm lazy so I aimed for 1.200 with an offset, seems solid. Of course every chip is different, but you're in the ballpark probably. I'm doing the daily log thing too, but with memory timings, since my ddr3-2400 didn't quite make its stock advertised timings, for whatever reason (mobo / cpu / ram).

 

[m6tzg6r]

Tried 1.160 and blue screened during a Cinebench run. Put it on 1.180 now, seems like the sweet spot for me. Which gives me 1.179 in windows with a core clock of 4498.95mhz.