E6750 stuck at 3.9GHz with 1.425v...

[LennyRhys]

Hi everyone,

I registered last week and have been itching to post for ages. I'm relatively new to overclocking and I've been fiddling with my system to see how hard I can push my E6750 for benchmarking. I'm not after a high 24/7 overclock; I really just want to get to 4GHz for benchmarking but so far everything I've tried hasn't worked.

With the CPU at 3.9GHz my BIOS settings are as follows:

FSB: 488MHz
CPU Vcore: 1.425
MCH overvoltage: +0.075
Memory clock: 976MHz
Memory timings: 5-5-5-15
Memory voltage: 2.1

These settings are definitley not orthos-stable, but all I wanted was to run super pi, which I managed without any trouble.

http://images6.theimagehosting.com/SuperPI_3.9GHz.th.PNG (http://server6.theimagehosting.com/image.php?img=SuperPI_3.9GHz.PNG)


I'm still using the stock intel cooler and my idle temps are approaching 50C; but it's the chipset I'm most concerned about because for one thing I have no way of reading its temp and I don't know how much extra voltage is safe.

The following settings are the hardest I've pushed my system so far, and at these settings my system automatically reboots/resets the FSB to 333MHz shortly after it posts (sometimes before). I made it to the desktop once, for all of one second. :ROTF:

FSB: 501MHz
CPU Vcore: 1.5v
MCH overvoltage: +0.225
Memory clock: 1002MHz
Memory timings: 5-5-5-15
Memory voltage: 2.1

Questions:

1) Have I hit an FSB wall below 500MHz? or
2) Might my CPU need more than 1.5v to reach 4GHz? or
3) Does my chipset need more voltage? or
4) Does my memory need more voltage?

Thanks in advance for your help, and any suggestions would be much appreciated. :up:

[LennyRhys]

OK after further tweaking I managed a stable overclock of 4GHz with the following settings:

FSB: 501MHz
CPU Vcore: 1.5125v
MCH overvoltage: +0.25
Memory clock: 1002MHz
Memory timings: 5-5-5-15
Memory voltage: 2.15

Finally got my Super Pi score below 13s :cool:

http://images6.theimagehosting.com/SuperPI_4GHz.th.PNG (http://server6.theimagehosting.com/image.php?img=SuperPI_4GHz.PNG)

I'm getting a Zalman CNPS9700LED for Christmas which will definitely help out a lot. I know it's not the best air cooler, but I don't need my temps to go down much more than 15C which the Zalman should happily manage with the assistance of lapping and some Liquid Pro "metal" TIM.

Please let me know if there's anything I can do to improve this overclock/Super Pi benchmark. Thanks. :up:

[jas420221]

You got to 4Ghz on stock air cooling?

[MotF Bane]

Welcome, Lenny.

It's almost certainly temperatures stopping your current stability. You also know I'll advise something better than a Zalman, and skipping the liquid metal TIM, but do what you will. Maybe somebody here can persuade you more effectively.

[mad_skills]

I like the most "approaching 50C on stock @ 3.9GHz..". :D
I got 55C full load in prime95 and Orthos @ 3.6GHz on only 1.38750V.
With my TRUE120.
If you got 4GHz on stock, you are either mad or brilliant.

[revogamer]

4Ghz on stock cooler, get better cooling, Thermalright Ultra 120-Extreme!

[jmmtn4aj]

How much is a Zalman 9700? Over here it costs more than a TRUE + Scythe S-Flex, making the TRUE a better option..

[LennyRhys]

If you got 4GHz on stock, you are either mad or brilliant.

Mad, definitely. This has everything to do with the quality of my components and nothing to do with my brilliance. I just wanted to do a Super Pi 1M run and I managed that so I'm happy. Next stop: 4100MHz (probably with the Zalman). :p:


It's almost certainly temperatures stopping your current stability.

Thanks for the welcome; nice to see you here. ;) The highest voltages I have used so far have been the ones that stabilized my system, so I think I was undervolting my CPU core/MCH/memory. If heat was the problem, wouldn't these higher voltages have made my system even less stable?

And I'm afraid I'm getting the Zalman and the Liquid Pro seeing that both of them have already been bought - the Zalman is even wrapped ready for the 25th. I'm making it my mission to do a good job of the lapping and installation, and I'll get back to everybody with some figures (hopefully numbers that will surprise people).

Over here the Zalman 9700 is equivalent to $65 and the TRUE120 is $80+.

[mad_skills]

I think it would be a wise investment for you to add those 15$ and get a Thermalright instead of the Zalman.:up:

[zsamz_]

yup the 120 deffinatly much better on load -10c:D

[RPGWiZaRD]

I wish I was "stuck" at 3.9GHz with 1.425v!!! :D

3.75GHz ~1.52v here. :p: Don't know why you need to get more, that's an amazing result already, most E6750 doesn't do more than 3.7~3.8GHz on reasonable voltage on air.

[Northwood]

the liquid pro is good stuff, but make sure you purchase a fine artists paintbrush to apply it, it wont spread easy, they suggest cotton buds but that leaves fluff in the metal.

fore warned is fore armed :)

[mad_skills]

I wish I was "stuck" at 3.9GHz with 1.425v!!! :D

3.75GHz ~1.52v here. :p: Don't know why you need to get more, that's an amazing result already, most E6750 doesn't do more than 3.7~3.8GHz on reasonable voltage on air.
I also got 3.9GHz stable and 4GHz stable but i needed 1.5V and over so i left 3.6GHz for 24/7 on very low vcore @1.37500V.
The 3.75Ghz on 1.52V you got there is a lot of vcore for that frequency.

[LennyRhys]

the liquid pro is good stuff, but make sure you purchase a fine artists paintbrush to apply it, it wont spread easy, they suggest cotton buds but that leaves fluff in the metal.

fore warned is fore armed :)

Yeah thanks for the heads up. Been doing a lot of research on Liquid Pro and I am going for brush application. I have more than ten very nice artists' brushes at home anyway, so all is good. :cool:

[stuck]

http://img215.imageshack.us/img215/4813/overclockersng2.jpg

Core 2 Duo E6750 (505x8)
Vcore: 1.60V
Fsb: 505
Mem: 505 (1010)@4-4-4-4-2T@2.2V

with the hw on my firm...

i think the fsb of the mobo locks my oc, the mobo boots up to 515x8 but isn't stable to enter winsux, in few weeks i try to bench with DICE, c ya...

[LennyRhys]

I think my system is just stable enough to run Super Pi at 4GHz with 1.5125v - I did Super Pi 1M at 3.8GHz with 1.393v, but bumping the voltage up to 1.425 isn't enough for 3DMark06 with that clock speed, which goes to show that Super Pi is obviously a small snack for the CPU. When I get better cooling my intention is to run Mark06 at 4GHz with a good overclock on my GTX, and for that to work I reckon I'll need closer to 1.6v for the CPU.

[LennyRhys]

OK I just completed a run of 3DMark06 at 3.75GHz with the CPU at 1.425v, and during the CPU test one core peaked at 71°C which is high enough for my liking!! The Northbridge voltage was increased by 0.15v and I left the memory at 2.1v. I also moderately overclocked my GTX (620/1415/1902). The result of all this tweaking? An increase of 558 marks, so now I'm just ten marks away from 13k. :D

For the guy who sent me a PM (which I can't reply to because you have 0 posts) - I haven't touched any other voltages/frequencies besides CPU, memory, and chipset. You HAVE to increase the chipset voltage to successfully boot at 4GHz - I started to bump up the NB voltage at 469MHz FSB (CPU 3.75GHz), and my system wasn't stable for Super Pi until I increased it by 0.075v.

[Rob94hawk]

Nice results! I'm looking to crank up my E6750 this week and see what this Gigabyte X38T/DDR3 combo can do.

[LennyRhys]

You have a very good CPU cooler so you should easily be able to bench super pi at over 4GHz, seeing that I can do 4GHz with the stock HSF.

[nidecker]

Hi! Mine needs 1,45V for take 3,8Ghz and 1,55V for 3,9Ghz both orthos-stable.

Yours seems a nice cpu but try to use a stability test like orthos or prime :)

[LennyRhys]

I just cracked 13k on Mark06 - bumped my GTX to 636/1450/1950 and kept the CPU at 3.75GHz. Increasing the core by a further 16MHz and the memory by 25MHz earned me nearly 400 marks. LOL.

3DMark06 13,354 (http://service.futuremark.com/orb/resultanalyzer.jsp?projectType=14&XLID=0&UID=12666184)

[Brian MP5T]

Very Good Clock and Scores.

I agree that the Stock on Air will eventually kill the CPU or it's ability to remain stable for duration.

I had a 6750, but replaced it with a Q6600 because they clock a 5 Grand Futuremark with hardly any effort. The Q is now only $245.00 here.

[LennyRhys]

Very Good Clock and Scores.

I agree that the Stock on Air will eventually kill the CPU or it's ability to remain stable for duration.

I had a 6750, but replaced it with a Q6600 because they clock a 5 Grand Futuremark with hardly any effort. The Q is now only $245.00 here.

Thanks. :up: TBH, as long as my benchmarking overclocks are short and sweet, I see no reason why they should affect my processor's longevity. Some people run their processors at these temps (and higher) for hours with Orthos or the like and see no ill effects; on the contrary, my CPU endured 60°C for all of five minutes, 65°C for about one minute, and 70°C for about fifteen seconds.

My case is largely responsible for my passable temps - I have all five case fans running with the top 200mm and back 120mm set to the highest speed (for benchmarking), and this time my CPU load temps were 6°C lower, peaking at just 65°C - not bad with 1.425v burning the stock cooler. :D My 8800GTX fan was at 100% for these test runs, and the diode temp never exceeded 60°C.

And yeah, the Q6600 is a beast on 3DMark06 - it scores higher at 3.6GHz than the QX6800 at 3.8GHz. :eek:

[Brian MP5T]

And yeah, the Q6600 is a beast on 3DMark06 - it scores higher at 3.6GHz than the QX6800 at 3.8GHz. :eek:

The Essence of this forum is not meant to be

"Get the Biggest Number"

It's more.

"How big of a number can I get on this CPU"

However, If the goal is to aquire a number for a particular reason... then the easy way is always buy a sick CPU.

Is the case an Antec 900?

[LennyRhys]

Yeah Antec 900 with five fans plus an extra internal fan for chipset cooling. And I thoroughly understand the essence of this forum; I was just making an observation. You'd think a C2E would score better than the Q6600.

[counsol]

Please dont start doing folding on that unstable 4ghz cpu.. you'll do more harm than good