I5 2500k vcore

[d1mich]

This is my first Build and I'm trying to achieve an OC of 4.2-4.4 I have an I5 2500k, Asrock Z68 Extreme 3 Gen 3. The stock vcore on load is 1.216-1.241. I changed the multi to 40 and the vcore raises to 1.341. I tried the Auto settings just to see what they were set at and at turbo 4.0 its at 1.341 and turbo 4.2- 1.351. I've tried offset and fixed but anything over stock and it jumps to 1.34. I was hoping I could get 4.2 with 1.3v or under. My question(s) are: What am I doing wrong that makes it always jump up to 1.34 or is it just a chip that requires more juice?

 

[jwk3]

I'm not sure if this is called the same on your motherboard but to get 4.2-4.4 you DON'T need to enable the overvoltage option (which is called "PLL overvoltage" on my MSI motherboard). I think this is the turbo you are referring to.

Does PLL overvoltage ring a bell? it allows the Vcore to increase to get better OC results but is not normally needed if you are staying below 4.5.

another point is that each chip is different, so don't get disappointed because you haven't got the same results as another user . I am running at 4.4 and at 1.295 Vcore (yes an i5 2500k), which I think is pretty average.

 

[d1mich]

PLL overvoltage is disabled. additional turbo voltage is set at .05 i believe I can't disable it so its either auto or the lowest .05

 

[jwk3]

OK, can you tell me any options you have on your motherboard? on second thoughts, re-reading through your OP; are you using auto Vcore?

 

[d1mich]

Fixed 1.25 to try and see if I could hit 4.0 at stock

 

[diet_pepsi]

I have the exact same setup and I am running at 4.2 and under 1.2v. I am sure there are others who have this same combo but if nobody is able to solve your issue I will reply with my bios settings when I get home from work.

 

[d1mich]

That would be great. Should I have the speedstep stuff, c1 c3 disabled?

 

[d1mich]

I was using cpuz 1.54 and updated to 1.60 and everything seems fine. I was able to go all the way to 4.7 before i couldn't boot into windows. Weird thing now is when I'm running p95 the frequeny goes as low as 4.1 when its set at 4.6 voltages top off at 1.276 after 30 mins of p95 temp 59/60. So what is causing the frequency to drop?

 

[diet_pepsi]

I am using CPUid 1.58 and HWmonitor 1.18 and I have no issues (or at least I think I don't).

I decided to use Offset mode (instead of fixed) for voltage as it allows the CPU to step down when idling.

My bios settings have the CPU running at 1.65ghz @ ~0.85v at idle and 4.22ghz @~1.15v at load (P95 -- using P64v2511). I am running two units with these settings and both are P95 stable. Both are running Win 7 ultimate 64 bit. The frequency and voltage numbers are what I am seeing in CPUid and HW monitor.

I am by no means an expert and I am sure there are others who are far more knowledgeable than I am so if there are any suggestions for better bios settings I would certainly welcome them.

Here are the settings from the OC Tweaker page of my BIOS (BIOS has been updated to latest version) -- let me know if you have any questions and I will do my best to answer:

Load optimized CPU OC – disabled
Load optimized GPUOC – disabled

CPU Config section
CPU ratio – all core
All core – 41
Host clock override – 103.0
Spread spectrum – auto
Intel Speedstep – enabled
Intel turbo boost – enabled
Additional turbo voltage – +0.004V
Internal PLL overvoltage – Disabled
Long duration power limit – Auto
Long duration maintained – auto
Short duration power limit – auto
Primary plane current limit – auto
GT overclocking support – disabled

Voltage configuration section

CPU core voltage – offset mode
Offset voltage -- -0.130v
Everything else (in voltage config) – auto

 

[d1mich]

I believe the turbo power limit was causing the frequency to drop. Here are my current settings at 4.5

CPU Ratio-45
PLL overvoltage - disabled
gt over clock - disabled
speedtsep - enabled
short duration power limit - 250
long duration power limit - 250
additional turbo voltage - +0.004
core current limit - 250
spread spectrum - disabled
power saving mode - disabled
offset voltage - 1.280/1.288 in bios
offset - +.005
LLC - level 2
all other voltage options - auto
Advanced cpu settings
C3 - disabled
c6 - disabled
package c - disabled

I've only been able to run prime for a little over an hour and the voltage from cpuz reads 1.248-1.280, however in hw it reads my highest voltage of 1.31. Do I need to adjust the offset for 1.31 or is it fine where its at. I'm going to run prime tonight for at least 8 hours. 1 hour temps were around 62 with 66 the high.

 

[diet_pepsi]

Those voltages are quite safe, but make sure to monitor your temps when running your p95 tests.

You might be able to do a little better if you use the offset setting to lower the voltage. If you have the patience, play with it a little and see how low you can get. Or if you want to leave the voltage as-is, play with the multiplier to see how high you can get. Bclock can also be used for smaller tweaks (I find it works up to 103) but changing bclock will also overclock you memory.

I didn't go above 4.2 -- that was enough to easily run all of the games/emulators/etc. that I use. At 4.2 I was able to find a sweet spot at under 1.2v, which avoids excessive power consumption.

I left all of the power saving settings enabled (but you don't have to).

There are definitely others here who can comment on their 2500k sweet spots at 4.5 (or higher).

 

[d1mich]

So after 8.5 hrs of prime95 my temps were 60/65/68/68 vcore was 1.32 but RAM usage was only 2.99 and I have 8 so I'm going to have to do another prime run. Then I'll try to lower the vcore some.

 

[diet_pepsi]

The temps seem reasonable -- best of luck with your tinkering!