Need help with overclock [core i5 750 + asus p7p55d-e pro]

[siphor1987]

I'm having a lot of difficulty overclocking my i5 750. I think I'm just unlucky and got a bad chip because it is only stable at 3.6ghz with 1.4v. I also noticed that even though I set the vcore to 1.4v in the bios, this drops to 1.328v under load in windows when doing a prime95 test. Is this normal? Should I enable load line calibration? Currently, the load temps are 59-58-58-60 degrees C.


Here are the parts i'm using:

core i5 750
asus p7p55d-e pro
g.skill ripjaws 2x2gb ddr3 1600
corsair tx750w powersupply
hd radeon 5870
noctua nh-u12p se2

bios settings:

blck: 180
multiplier: 20
vcore: 1.4v (1.328v under load)
vtt: 1.25v
vdram: 1.50v
c1e: disabled
qpi: lowest
load line calibration: disabled
pch: 1.9v
spread spectrums: off
dram timing: 9-9-9-24

Should I bump up the vcore some more or is it already too high? I have prime95 running for about 40 mins and so far error free. Any suggestions is much appreciated! Thanks.


*Edit* So I managed to get the cpu swapped for another one and this one has a different batch #, and what a difference that made. Here are the settings I am using so far:

blk: 195
multiplier: 20
vcore: 1.30v (load temps: 61,63,58,61)
vtt: 1.30v
vdram: 1.50v
c1e, speedstep: disabled
qpi: lowest
LLC: enabled
pch: auto
spread spectrums: disabled
dram timings: 9-9-9-24 1T

So far i'm pretty happy with getting 3.9ghz with 1.30v but I think I can push for 4ghz. I did notice that this cpu runs a bit hotter than my old i5 750 but unlike my old one, the new chip requires a lot less volts to the vcore to get a decent overclock.

[Patramix]

thats too much V on the CPU imo for a 3.6ghz but all chips are different

i am using the same CPU MOBO RAM

try enableing LOAD-Line Calibration and lower the V on the CPU. it did all the difference for me

i am currently running

200 blck
19 multi (for 3.8ghz)
1.325 V on CPU
1.3 IMC
1.5 ram(same ram)
1.8625V on the PLL(PCH) for a Bclock of under 200 most people/guides/reviews never went over 1.8
qpi auto

all that with 5-8C more then you with a 212+

with load-line disabled i ran allot of troubles getting a stable OC with under 1.4 V also

also updating the Bios helped me

[martin_metal_88]

You probably have a unlucky chip. Try to get your Vcore at 3.5-3.7 and put some load line calibration. Not the best thing to do but if you want to get higher clock that can be the issue. Also try to get the multi a little down and up the BCLK or vice versa if you can to try any possible setting. Yes it's normal that CPU-z show a little under the bios that's aways happen. Just don't worry about it.

[siphor1987]

Originally Posted by Patramix

thats too much V on the CPU imo for a 3.6ghz but all chips are different

i am using the same CPU MOBO RAM

try enableing LOAD-Line Calibration and lower the V on the CPU. it did all the difference for me

i am currently running

200 blck
19 multi (for 3.8ghz)
1.325 V on CPU
1.3 IMC
1.5 ram(same ram)
1.8625V on the PLL(PCH) for a Bclock of under 200 most people/guides/reviews never went over 1.8
qpi auto

all that with 5-8C more then you with a 212+

with load-line disabled i ran allot of troubles getting a stable OC with under 1.4 V also

also updating the Bios helped me

I tried those settings and core #3 failed prime95 blend test within seconds. It seems that core #3 is the one holding the processor back because it tends to fail immediately. Right now I have the vcore back up to 1.4v and running prime95 to see how stable it is. I'll start lowering the vcore if it is prime95 stable. Temps seem to be fine at less than 70 degrees C load but i'm disappointed the chip I have takes so much voltage to overclock when I see others only needing about 1.25-1.35v for 3.7-4.0ghz.

[Patramix]

lol i had the same problem, core 3 failed allot for me also, looks like where in the same boat, my max temps are around 68C with prime95

i also think i have the north bridge at 1.1v also(forget whats its called one of the last in the list)

a 1.9PLL might help you a little too if you havent tried it, without load-line i ran these same settings but at ~1.4v

so far its stable, ran 20 ish hours of prime and no problems so i keep it there.

[siphor1987]

I have to use 1.4v regardless of whether I have LLC on or off. What batch # is your i5 750?

[macca609]

the i5-750 has turbo mode as an option on it. As such you have reached your max (intel specifies that 3.6ghz is the max clock with turbo mode engaged). You must disable turbo mode in the bios to gain a higher clock.

Hope you can get higher because I have just ordered that cpu (gulp!)