# i7 4790 Overclock Even Further



## Damocles (Jul 5, 2016)

I have managed to overclock my non K CPU from 100 to 106.5 bclk. My current CPU speed is 4.22 GHz and the system is completly stable under this overclock. But if I set the bclk to 107 or up, it becomes unstable. Is it possible to overclock CPU even further by changing voltage or RAM timings or anything else?


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## ratirt (Jul 6, 2016)

Well I think You might have hit the roof with your CPU. Without "K" version the OC is limited a lot. still that's not a bad result but compare to "K" it's like nothing. you can try Voltage change and maybe there's some other stuff that block your OC. MOBO, RAM etc. Good luck.


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## Damocles (Jul 6, 2016)

Well, that's a shame. I would have bought a K CPU but it was much more expensive back when I bought the parts and assembled my PC.

But to be completely honest, I don't see any difference in performance when gaming. If I overclock a GPU with afterburner, that's a whole different story.


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## basco (Jul 6, 2016)

at your monitor resolution gtx 1080 is overkill and i dont see the need for overclocking your graphic card.
and 200mhz on your cpu will not make much diff while boosting to 4.0ghz standard


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## Tatty_One (Jul 6, 2016)

When you increase the Bclk does it also increase the PCI-E speed?  If so can you lock the PCI-e independently as that would/could cause instabilities.  Additionally, is it playing with your ram speeds also?


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## Damocles (Jul 6, 2016)

basco said:


> at your monitor resolution gtx 1080 is overkill and i dont see the need for overclocking your graphic card.
> and 200mhz on your cpu will not make much diff while boosting to 4.0ghz standard


Overkill? Tell that to GTA V grass quality or AC Syndicate PCSS shadows  I mostly play demanding games on max settings (of course I want 60 FPS), but a lot of them are struggling to maintain 60 fps especially when I turn on anti-aliasing or similar resource hog settings. This is also a reason why I want to overclock my non-K CPU as highly as possible --> to get the most of my system.


Tatty_One said:


> When you increase the Bclk does it also increase the PCI-E speed?  If so can you lock the PCI-e independently as that would/could cause instabilities.  Additionally, is it playing with your ram speeds also?


I actually don't know. All my BIOS settings are at their default values except BCLK. Haven't really played with other things.


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## basco (Jul 7, 2016)

106,5 is really high but it should be the end.
there is no hidden setting to push these cpu´s higher-if there is you would see it all over inet.
and some settings in game are not worth the lower frames but with nearly null visual effect-my2c.


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## TheGuruStud (Jul 7, 2016)

Don't worry, haswell OCs like shit. Look at the worthless clocks I have. Screw intel.
These aren't the only pieces of shit I've encountered that maxed out this low.


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## Damocles (Jul 7, 2016)

Oh well, I will live with this OC. Maybe if I'll have the time I'll play with some other options in BIOS.


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## basco (Jul 8, 2016)

the only thing i can think of is cache frenzy or how is this handled on non-k chips.
can ya up the multi on cache?
will not bring much but you are after every fps.


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## Vayra86 (Jul 8, 2016)

TheGuruStud said:


> Don't worry, haswell OCs like shit. Look at the worthless clocks I have. Screw intel.
> These aren't the only pieces of shit I've encountered that maxed out this low.



The age of Monster OC"s is over anyway buddy. Intel and AMD already do it for us since Sandy Bridge and the margin for error gets tighter every new gen, and much tighter with every new process node.

Enter 16/14nm where you can see GPU's that auto-OC to within 5% of their maximum stable clocks...


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## TheGuruStud (Jul 8, 2016)

Vayra86 said:


> The age of Monster OC"s is over anyway buddy. Intel and AMD already do it for us since Sandy Bridge and the margin for error gets tighter every new gen, and much tighter with every new process node.
> 
> Enter 16/14nm where you can see GPU's that auto-OC to within 5% of their maximum stable clocks...



I know, but it's rather pathetic for haswell. You have to win the lottery if you want a good OC.


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## Tatty_One (Jul 9, 2016)

Your 106.5 Bclk is the limit you can go simply because you are probably also overclocking the PCI-e and it's that causing the instability.


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## Hood (Jul 9, 2016)

Damocles said:


> I have managed to overclock my non K CPU from 100 to 106.5 bclk. My current CPU speed is 4.22 GHz and the system is completly stable under this overclock. But if I set the bclk to 107 or up, it becomes unstable. Is it possible to overclock CPU even further by changing voltage or RAM timings or anything else?


  That's not bad, and as you said, it's only a couple FPS in games when OCing.  If you want a little bit more, higher memory clocks may help you get the most out of your CPU overclock.  RAM prices are at an all-time low, 16GB of 2400MHz as low as  $60 (same kit in 1600MHz is $55).  This can also help reduce load times for games and levels.  I recently was bored and decided to overclock my Adata 2400 kit, and got it up to 2666, completely stable.  Every little bit helps...  Maybe not very noticeable in games, but it certainly helps with all the other tasks (editing, rendering, compressing, converting video & audio, etc).


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## Recon-UK (Jul 9, 2016)

You are incredibly lucky to have even got it that far.


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## Aquinus (Jul 9, 2016)

Bumping the bclk on the 4790 will increase the clock speed of the DMI between the PCH and the CPU as well as the PCI-E root complex on the CPU. Most PCI-E devices don't take too kindly to the bus frequency changing however, the PCH is a different story. You would probably get a different result if you removed or disabled every PCI-E device however, DMI is very similar to how PCI-E works.

*IF* the PCH is the limiting factor and not the PCI-E devices, increasing the PCH voltage *might* get you a little more out of it. However I say this with extreme warning as the PCH is passively cooled and pumping more voltage through it could prove to be unwise. Either way, @Tatty_One is correct, the PCI-E bus is usually the main reason why you can't get more out of the bclk on this generation of CPUs unless you have a CPU like Skylake with the independent clock gens or, with skt2011(or -3) with bclk straps (an internal multiplier if you will,) but even those are limited to around 5Mhz overclock over the strap (+/- 3Mhz.)

The PCH is a little odd because it usually has more than one voltage and it's uncertain to me which ones drive which components. Either way, I urge caution should you decide to muck around with PCH voltages.


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## Tatty_One (Jul 9, 2016)

Aquinus said:


> Bumping the bclk on the 4790 will increase the clock speed of the DMI between the PCH and the CPU as well as the PCI-E root complex on the CPU. Most PCI-E devices don't take too kindly to the bus frequency changing however, the PCH is a different story. You would probably get a different result if you removed or disabled every PCI-E device however, DMI is very similar to how PCI-E works.
> 
> *IF* the PCH is the limiting factor and not the PCI-E devices, increasing the PCH voltage *might* get you a little more out of it. However I say this with extreme warning as the PCH is passively cooled and pumping more voltage through it could prove to be unwise. Either way, @Tatty_One is correct, the PCI-E bus is usually the main reason why you can't get more out of the bclk on this generation of CPUs unless you have a CPU like Skylake with the independent clock gens or, with skt2011(or -3) with bclk straps (an internal multiplier if you will,) but even those are limited to around 5Mhz overclock over the strap (+/- 3Mhz.)
> 
> The PCH is a little odd because it usually has more than one voltage and it's uncertain to me which ones drive which components. Either way, I urge caution should you decide to muck around with PCH voltages.



Indeed, I am just about to pull the trigger on a Skylake 6400 (obviously non K) and try some Bckl overclocking, I have seen results of 4.7gig +.


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## Aquinus (Jul 9, 2016)

Tatty_One said:


> Indeed, I am just about to pull the trigger on a Skylake 6400 (obviously non K) and try some Bckl overclocking, I have seen results of 4.7gig +.


I'm waiting for this awesomeness to find its way into the next HEDT socket. My 3820 is still plenty fine for the time being and always has that 125Mhz BCLK strap should I require more than 4.3Ghz. Maybe then we'll get to have some fun with Xeons again.


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## Damocles (Jul 10, 2016)

Well to be completely honest, when I said I only changed BCLK the ram speeds also increased from 1600 MHz to about 1700 MHz even though my CPU can't support speeds above 1600 MHz.

That said, my PCI speed probably increased to but I haven't found where to check that or how to block this option from changing.


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## Hood (Jul 10, 2016)

Damocles said:


> Well to be completely honest, when I said I only changed BCLK the ram speeds also increased from 1600 MHz to about 1700 MHz even though my CPU can't support speeds above 1600 MHz.
> 
> Your CPU can support any RAM speed, 1600 is just the starting point for minimum MHz.  Your Asus Z97 P supports at least 3200MHz (per Asus specs).  It doesn't matter if it's a K or non-K CPU, i7, i5, or i3.  (I have run RAM@2400MHz on an Asus Z87 K with an i3-4130) - as long as your motherboard is Z87 or Z97 it has all settings for RAM speed and timings.  The limiting factor is the chipset, and  and since you splurged on a Z97 board, you're good to go.  1600MHz is the nominal (minimum) RAM speed, such as you'd run on a H87 or H97 board, which has no RAM dividers.


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## Damocles (Jul 10, 2016)

Well, to be honest I didn't know that. Thanks for sharing this info 

Do you by any chance know where can I disable PCI-E speeds so they won't change when I overclock?


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## Aquinus (Jul 10, 2016)

Damocles said:


> Do you by any chance know where can I disable PCI-E speeds so they won't change when I overclock?


The clockgen for the bclk and PCI-E is the same. You can't decouple them. The best you could do would be to remove any PCI-E devices you have, which includes your GPU so, I would say it's probably not worth doing anything to it. If you can get more by over-volting your PCH, that's great, if you can't then this is the end of the line.


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## hat (Jul 11, 2016)

Tatty_One said:


> Indeed, I am just about to pull the trigger on a Skylake 6400 (obviously non K) and try some Bckl overclocking, I have seen results of 4.7gig +.





Aquinus said:


> I'm waiting for this awesomeness to find its way into the next HEDT socket. My 3820 is still plenty fine for the time being and always has that 125Mhz BCLK strap should I require more than 4.3Ghz. Maybe then we'll get to have some fun with Xeons again.



Until intel pulls the plug on you because you didn't spend $7000,0000 for the K edition.


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## cadaveca (Jul 11, 2016)

Damocles said:


> Well, to be honest I didn't know that. Thanks for sharing this info
> 
> Do you by any chance know where can I disable PCI-E speeds so they won't change when I overclock?



In a way, yes. Try like 125 BCLK, 166 BCLK, and dropping multiplier down



Aquinus said:


> The clockgen for the bclk and PCI-E is the same. You can't decouple them. The best you could do would be to remove any PCI-E devices you have, which includes your GPU so, I would say it's probably not worth doing anything to it. If you can get more by over-volting your PCH, that's great, if you can't then this is the end of the line.



That actually depends on the board. Some boards feature external clockgen capable of doing much higher than other boards.


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## Aquinus (Jul 11, 2016)

cadaveca said:


> That actually depends on the board. Some boards feature external clockgen capable of doing much higher than other boards.


On a non-skylake board? I thought that wasn't done until the DC ship had sailed.


cadaveca said:


> In a way, yes. Try like 125 BCLK, 166 BCLK, and dropping multiplier down


Doesn't he need to have BCLK straps for that to work? That's different than just adjusting the BCLK because it actually adjusts DMI and PCI-E clock multipliers. Just changing the BCLK as you suggest probably won't work unless you know something that I don't.


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## cadaveca (Jul 11, 2016)

Aquinus said:


> unless you know something that I don't.


You are ignoring that Haswell has BCLK straps? Both Z87 and Z97 support this. Straps worked since before the 4770K launch.  You have to do a cold-start to get it enabled though, and not all boards do that (why I am not sure.




Aquinus said:


> On a non-skylake board? I thought that wasn't done until the DC ship had sailed.



Uh, yeah, Where have you been? AMD-land?


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## BiggieShady (Jul 11, 2016)

cadaveca said:


> Uh, yeah, Where have you been?


I can't let you do that Dave. 
I have to defend fellow knowledgeable bastard. 
Wherever he may have been, I'm sure he wasn't reviewing tons of motherboards


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## Aquinus (Jul 11, 2016)

cadaveca said:


> You are ignoring that Haswell has BCLK straps? Both Z87 and Z97 support this. Straps worked since before the 4770K launch.  You have to do a cold-start to get it enabled though, and not all boards do that (why I am not sure.


I thought that BCLK straps were only available to K-edition CPUs for Haswell (not -E) and wasn't available otherwise although, I can't quite recall where I read that so, my memory could be failing me. I feel like we would have heard a lot more about being able to overclock non-K CPUs before Skylake if that was the case. Maybe not?


cadaveca said:


> Uh, yeah, Where have you been? AMD-land?


Pretty sure that between Sandy Bridge and Devil's Canyon that the bclk was tied to other clock domains. I'm not talking about skt1366 and earlier, I'm thinking more skt1155/skt2011 until Skylake but please, continue to be a smart ass.


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## cadaveca (Jul 11, 2016)

Aquinus said:


> I thought that BCLK straps were only available to K-edition CPUs for Haswell and wasn't available otherwise although, I can't quite recall where I read that so, my memory could be failing me. I feel like we would have heard a lot more about being able to overclock non-K CPUs before Skylake if that was the case. Maybe not?


That's why you need the board with external clockgen. Intel locked-out OC on non-K with Skylake as well, but hacked BIOS allows it to work; Haswell is no different IIRC.

But you have a good point!

Maybe it changed since I was at IDF. Pretty sure you can find news articles about Intel claiming Haswell non-K bclk here on TPU, even. But maybe that turned into boards that were not supposed to support OC being able to do so...


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