SOLVED Views on i5 2500k overclock to 4.5GHz

[lilg_06]

I've overclocked my 2500k to 4.5GHz however I've found that it needs a lot of juice to run stable.... My settings below.
Multiplier: 45x
Base clock: 100
Ram voltage: 1.65V (as on label)
Ram timings: 9,9,9,24,2 (Corsair XMS3 8GB 1600MHz / 2x4GB Kit)
Voltage Offset: +0.005V
LLC: Enabled (Asus P8Z68-M Pro motherboard, can't set levels, enabled/disabled/auto only)
Spread spectrum: Disabled
PLL Overvoltage: Disabled (Running at 1.8V Stock, can't go lower, 1.8V or 1.9V options only)
vtt: Stock 1.050V
C3 and C6 disabled
C1E and speedstep: enabled

Now, after running IBT, I get peak voltages of 1.40V, im guessing this is when LLC kicks in, voltage never goes higher than this, on prime 95, the voltage is between 1.37-1.38V whilst running blend. At these voltages I pass IBT on max ram settings, 10 loops (have not tried more). And prime 95 runs perfect for 12+ hours, maximum prime time for 15 hours and it was stable.

If I reduce the voltages I end up getting BSOD error 124 or rounding errors in prime95, with the 124 error I tried upping the vccio gradually rather than the offset however then I end up getting BSOD 101, so its definitely too low a vcore. And I can't reduce pll voltage, minimum is 1.8V.

Just wanted to hear your opinions on these settings, acceptable? Anyone else running these voltages at this clock speed.
Btw. My 4.2GHz clock is at 1.28V, bsod 101 any lower.

Anything past 4.2GHz, and I really have to up the vcore.
Temps are also within limits, using a noctua nh-d14 cooler.
Highest is 78C with IBT, and around 68 with prime.
Normal pc use, encoding videos, etc, around 62C max.

 

[djscrew]

its pretty standard for it to start sucking an exponential amount of juice once you get into the mid to higher 4.x

1.4 or below should be acceptable for 24/7 use in my opinion.

 

[lilg_06]

okay thanks. I've turned llc off, voltage ranges and max voltages are still the same, I've found that turning llc off actually reduces heat output.

passed ibt 10 loops on max, prime95 7 hours in on blend at the moment.....

 

[False Christian]

I'm running my i5 2500K at 4.5GHz using 1.295 volts. I can get to 5GHz but that requires 1.50 volts.

 

[lilg_06]

I'm running my i5 2500K at 4.5GHz using 1.295 volts. I can get to 5GHz but that requires 1.50 volts.

Nice voltage at 4.5GHz
Do you stress test with IBT/prime95 or both?

Highest frequency I've taken my 2500k to is 4.6GHz, that requires 1.42V max, mostly at 1.40v at load.

 

[lilg_06]

Just a quick update, I did some research and found that if your motherboard has a GOOD VRM design, so it has a higher number of phase delivery systems, it is easier to stabilise a clock at lower vcore. Did some more research and found that a 4 phase system is good. But an 8 phase system is even better.
My asus p8z68m-pro has a 4 phase vrm power delivery system.

What did I do and what I found.
I purchased an Asus Z77 Maximus V Motherboard
Changed my motherboard, everything else is the same, and started my overclock again, now I'm stable at 4.5GHz with a vcore of JUST 1.33V, havn't tried lower yet, but thats much less than 1.4V in my opinion, can probably get to 4.6 at 1.35v, fingers crossed...

So in short, your motherboards vrm power delivery system will also affect your cpu vcore!
The higher number of phases reduces spikes in voltage to the processor, and it also delivers a more consistent voltage and current, fewer phases will not do the job so well.

 

[GotNoRice]

I've run my 2500k at 5Ghz, 1.48v since last September. Official Intel documentation lists Max Sandy Bridge VCore at 1.52v.

What I would be more concerned about, if anything, is running 1.65v DDR3 on a Sandy Bridge system. The IMC is designed for 1.5v ram with about 5% tolerance. 1.65v might work but that would have just as much odds of eventually causing degradation as using a higher VCore would.

The 2nd generation Intel® Core™ processors are a little touchie about the voltage on the memory. They like the memory to be 1.5v ±5% getting above this point can damage the memory controller on the processor. So if that is what the Bios is reading that your memory is set at don't change it.

Christian Wood
Intel Enthusiast Team

http://hardforum.com/showthread.php?p=1037771479#post1037771479

 

[silk186]

I'm run at 4.4 on stock voltage. I don't think it is worth playing with voltages to get a few hundred htz more

 

[spayced]

I'm run at 4.4 on stock voltage. I don't think it is worth playing with voltages to get a few hundred htz more

Nice vcore w/ that OC.

Not everyone can get lucky and have a nice chip like yours.

 

[lilg_06]

I've run my 2500k at 5Ghz, 1.48v since last September. Official Intel documentation lists Max Sandy Bridge VCore at 1.52v.

What I would be more concerned about, if anything, is running 1.65v DDR3 on a Sandy Bridge system. The IMC is designed for 1.5v ram with about 5% tolerance. 1.65v might work but that would have just as much odds of eventually causing degradation as using a higher VCore would.


http://hardforum.com/showthread.php?p=1037771479#post1037771479

I've changed my configuration for the ram a while ago, been running my memory at 1.5V and it runs stable with the default timings and the same frequency of 1600MHz, no stability issues.

I'm considering running my system at 1.46V 24/7 for a 4.8GHz overclock, anything below 1.46V and I can't get it stable at this speed. Will probably take my chip 1.5V+ to get 5GHz...
I wanted to get other overclockers opinions who have been running high voltages for a year at least before doing this, but every chip degrades differently so I guess there isn't really much of a point.

I've also noticed a trend in multiplier and voltages for my chip, this applies after 4.5GHz, I need to bump the vcore by 0.04V for every 1x incremental increase in the multiplier.
Right now I'm running at 1.34V at 4.5GHz, drops to 1.3V under load.
4.6GHz requires 1.38
4.7GHz requires 1.42
4.8GHz requires 1.46
(At load all voltages drop by 0.01V with LLC set to extreme)

But I did purchase the intel performance tuning plan, won't be active for a few weeks, gives me a bit of a safety net.

How is your 1.48V 5GHz overclock? Is this using offset voltages or manual?
Any changes to PLL?

 

[lilg_06]

I'm run at 4.4 on stock voltage. I don't think it is worth playing with voltages to get a few hundred htz more

It's difficult to stop pushing the chip to its limits.... lol

 

[False Christian]

It's difficult to stop pushing the chip to its limits.... lol

I here ya. Sometimes I can't sleep at night thinking about overclocking my i5 2500K to 5GHz but I have ta restrain myself and be happy with 4.7GHz.

 

[lilg_06]

lol, tell me about it.
I also ended up settling at 4.7GHz, temperatures at this clock are nice, voltage is a little on the high side, 1.42V, temps max at about 60C whilst gaming/encoding, the performance tuning plan is there just in case things get messy...

 

[bluezero5]

for 3930k

4.7Ghz 1.38V
4.8Ghz 1.45V
5.0Ghz 1.52V

Just watch your temps.
in general, conservative people say keep your voltage under 1.45V.

but I don't OC to play it that safe, so I live on 1.52V, and use LLC at 60% to keep the idle voltage lower.

 

[lilg_06]

Once my performance tuning plan is in effect I'll go all out, lol