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Any Suggestions on How To Reach 4.4ghz With a i7 875k?

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BigTerminator

BigTerminator

Member
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Joined
Jul 27, 2010
Location
Maryland
Hello, I have a Core i7 875k which means it has an unlocked multiplier. You'll see my specs in the sig. I'm stable at about 4.03ghz at around 1.32v on vCore and 1.35vtt. I'm at 193 bclk. Remember the Unlocked multiplier, all I have to do is bump up the multiplier to 23 to reach 4.4ghz. Now as I recall, all you would have to do is up the vCore and that's it, AM I Right with unlocked multipliers? I've even tested upping the vtt and PLL. I've tried 1.4v, 1.425v, 1.45v, 1.48v on the vCore with low vDROOP. I keep getting crashes, why? Is it the Low vDROOP? I've seen many people get 4.4ghz at around 1.45v, a lot of times under that. My Motherboard is very high end and should be able to get to at least 5ghz under lN2. I had an i7 860 previously, and that also wouldn't go above 4.2ghz. It could be the Mobo but I think I'm doing something wrong. Cooling is fine, at 4ghz I get around 60c with Prime 95. If any one had a p55 i7 at 4.4ghz or knows some good settings to use, please help. And DON'T refer me to an overclocking guide. I'm perfectly stable at 4ghz with no power saving features on. This is only very benching, I use 4ghz for 24/7 daily use.
 
Try a higher multiplier like x26 w/ a lower BCLK of ~170 = 4.42GHz, this w/ Vcore set to between 1.40 and ~1.48V depending on the VID.
 
Thanks for the suggestion, but it still crashed. Same question, if you just higher the multiplier, all you would need to do is up the vCore? Am I getting that part wrong. Redduc, what is your highest overclock? And what settings did you use. Again I'm good at 1.32v at 4ghz and 4.2ghz at about 1.4v. I really don't wanna go higher than 1.45v, I really shouldn't after seeing other people do it. Yes, I know not all identical components don't overclock the same but it should all be close. My temps at 4.2ghz are creeping a little, they get around 75c but stay at around 70c which is perfectly fine. 85c is where it crashes. Since from 4ghz to 4.2ghz, all I did was up the multiplier hence only upping the vCore, can I just keep that method going forever?
 
Just because some chips clock up to 4.4 doesn't mean that they all can. My i7 860 will do 4.0 with ~1.35v maybe even with a little less vcore and I've benched it at 4.2 but I never even tried 4.4 because my 4.2 was not rock solid stable. It could be that the max for you chip is around 4.3?
 
I"m in the process of building a near identical setup to yours, so I'm interested in how this progresses (i7 875 + Big Bang Fuzion + Sythe Mugen (YL Push/Pull))


Have you tried a lower multi, and higher bclk?

Like 200x20? Then 200x21?

With a low multi, what was your highest bclk you found stable? It's gotta be over 172!
 
You also may just need more vcore. Once you hit a certain point (and past 4.0 on P55 quads is getting to that point) you need alot of voltage for small increases. As your original post shows it too about .08v to go from 4.0 to 4.2 (1.32 to 1.4) so it will take more than .08 more for the next 200 mhz if you can get it at all.

And just because other chips can do a certain speed at a certain voltage doesn't mean yours can. I've seen i5 750's do 4.0 at under 1.3 vcore and mine took 1.44.
 
My i7 860 will do 4.9 Max on Air. But thats with 1.65V vcore and is just a suicide run.

I have benched Super Pi at 4.7-4.8 and have run 3D Mark 06 at 4.6. Again, with 1.6Vcore.

I have run Wprime 1024 @ 4.65 - 1.6V Vcore

I run mine 24/7 4.4 with 1.45Vcore and 1.35vtt.

One thing you may be running into is an unstable memory controller. Try backing your RAM down to 1066 while trying to get stability. Also your temps make all the difference.

TBH, if you can get 4.2 out of your chip, you should be completely satisfied. The last 200MHz account for not even 1% of a performance gain when the amount of voltage you have to pump into it is considered. Realistically 4.0 is really all you need unless your benching for points. If thats the case, you can't skimp on ANY hardware.
 
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750 watt PSU? what brand? There are so many things that must come together for a good OC.

If you have a crap PSU foe example the board may not be able to stabilize the voltage necessary to operate the CPU at the desired clocks. Many people do not realize that A CPU sucks a lot of power and at is rated voltage requires more amperage than any home appliance.

I am not saying it uses more power but the current is overwhelming and a bump or ripple will kill the clocks. If the flow is low there may also be issues as conflicts in actual and requested voltage can be an issue.

The IMC is another thing to consider. All I am saying is there is more to it for most people than add voltage and increase clocks.

Many of us here do just that but we also don't skimp anywhere.

From my experience MSi makes great boards but not the best clockers.
 
That BBFusion is a great board and 200bclk should be a breeze...

With that said, I hope such a nice system doesnt have a POS PSU...

Moving on, I agree with redduc. Lower the bclk and up the multi. Thats why you paid the bucks for that chip in the first place (or why you should have). But no, its not just raise multi and nothing else. You still have to consider your memory ratings and speed, vtt settings etc. I know you dont want to be referred to a/the guide, but you may want to take a look through it again if only to refresh your memory and fine solid methods of overclocking and learning what you are changing. :)
 
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In looking at the 4ghz club thread on OCN, most Lynnfield's are getting 4+ghz with a 20 or 21 Multi.
 
NorCalJason said:
In looking at the 4ghz club thread on OCN, most Lynnfield's are getting 4+ghz with a 20 or 21 Multi.
Click to expand...

Most lynnfields also don't have an unlocked multi like his 875k. I use the multi to do most of my clocking on my 655k as it's just easier for me to get everything where I want with 160 bclk (my board won't do 200 so to get 1600 on the mem I need to use 160)
 
Are you running with HT? The extra heat generated from HT makes bigger clocks harder to stabilize especially on air. The other day I was benching wPrime at 4.6 (socket 1366) on air and I couldn't control the temps well enough to complete the bench with 8 threads but I did manage 4. Some of these i7 chips run very hot at 4.4+. I like running on air but I'm now considering an upgrade to a decent water cooling loop for testing.
 
First off my PSU is a Corsair 750watt TX http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006 which is a good solid PSU. I would like to keep the bclk around 193 because my memory is good for 2300mhz. I have tried running it at 2000mhz with all of the defualt timings at around 170bclk but it is just as unstable. Can someone PLEASE answer this question? If all I do is up the CPU multi than the only factor in overclocking would be the CPU vCore? I'm running 4.4ghz just to bench and not daily use. My temps are very low so thats not the problem. I have a very high end board and I would most definitely like to keep the HT on. I know not all CPU's overclock the same but at 1.32v at 4ghz, I wouldn't think it would need 1.5v even though the voltage doesn't scale well at that level. If all else I might try the memory at 1600mhz at 133mhz bclk but that really shouldn't be the problem. Also does overvolting cause instability? I have done the increments by around .025v. Brutal Force what settings exactly do you use for 4.4ghz, like bclk and other settings?
 
Believe it or not almost every CPU has a voltage window.

Where xV will allow yClocks +/- zMhz

That being said from personal experience on AMD and Intel as well as observations just because 1.32v will give you 4.0 and no more does not mean that it will not take 1.52 for another 2-400 Mhz. Now this will also be a window and perhaps allow 4.6Ghz. There is no real magic number as every CPU is different. Add in the ram, motherboard and PSU (Yes you have a strong PSU but in your sig you do not note it).
 
I already answered the question about your voltages BT. To add to it, running your memory so high you will have to adjust your Vtt as well. You likely are not going to be able to run your memory and your CPU that high. The memory controller probably cant handle it.

What benchmarks are you running that you want 2.3k+ memory anyway?
 
I tried 1866mhz on RAM which is under the rated 2000mhz it comes at, with 165 bclk at around 1.5v and Prime95 failed in an instant with 1.35vtt still. Do you think it's the boards limit or the PSU. Is there a certain amount of AMPs you need for the CPU plug. At 4ghz my chip takes about 140w considering i7 9xx use around 200w for 4ghz. I know it can't be the CPU because I had a previous i7 860 that wouldn't go past 4.2ghz. I know my board is high end but could it be the board? I know the GD-80 which is cheaper has gotten that high before. Again I'm perfectly fine at 4ghz, just want some really high scores for HWBot. As for running at 2300mhz, if I can I will run at that and seen from wPrime it really helps but in real world apps it doesn't. What about PLL voltage and ICH, any other voltages I should bump up to salvage this overclock?
 
PSU can power it without flinching...unless its bad (which is doubtful..highly doubtful).

PLL is something that is normally left at stock, or sometimes even LESS, it depends on the setup so I have no accurate advice there.

The guide should be able to get you there if you follow its process. Remember, it isolates clockspeed, bclk, and MEMORY speed. You need to find out what your memory controller can handle really...

One other thing to note, your MEMORY STICKS are rated at 2k, that doesnt mean your memory controller which is on the CPU can get that high. Please note those are different things.

You are at a point in overclocking where cookie cutter settings arent going to cut it and its trial and error. List your major voltages and maybe something will stick out. Assuming you have them off auto which you should.........
 
BigTerminator said:
First off my PSU is a Corsair 750watt TX http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006 which is a good solid PSU. I would like to keep the bclk around 193 because my memory is good for 2300mhz. I have tried running it at 2000mhz with all of the defualt timings at around 170bclk but it is just as unstable. Can someone PLEASE answer this question? If all I do is up the CPU multi than the only factor in overclocking would be the CPU vCore? I'm running 4.4ghz just to bench and not daily use. My temps are very low so thats not the problem. I have a very high end board and I would most definitely like to keep the HT on. I know not all CPU's overclock the same but at 1.32v at 4ghz, I wouldn't think it would need 1.5v even though the voltage doesn't scale well at that level. If all else I might try the memory at 1600mhz at 133mhz bclk but that really shouldn't be the problem. Also does overvolting cause instability? I have done the increments by around .025v. Brutal Force what settings exactly do you use for 4.4ghz, like bclk and other settings?
Click to expand...

As I pointed out earlier. (I Learned this the hard way). INTEL only "officially" supports 1066/133 on their i7 Processors. A weak Memory controller could be affecting your overclock. While my chip will hit 4.9GHz, it is definitely not stable at those speeds. I can run stable enough at 4.6 but not prime stable, and even at 4.4 the heat is so high that if I try folding or other number crunching, the heat in the room becomes unbearable.

You need to consider both of these problems if you want to hit 4.4GHz, and unless you like a sauna, I'd recommend dropping it down to 4.0 for every day use.

Also read this thread concerning the IMC. And you will see why I point out this problem.

http://www.overclockers.com/forums/showthread.php?t=646515
 
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