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Overclocking the BCLK on 7600K?

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SPL Tech

Member
Joined
Nov 28, 2006
I have a MSI Pro SLI Plus Z270 mobo and I am running my 7600k stable at 4.8 GHz. Running at 4.9 GHz requires a bit more voltage than I would like for 24/7 (about 1.37v vs 1.31 for 4.8 GHz). As such, I am thinking 4.85 GHz which would require a BLCK of around 101.1. Is it safe to mess with the BCLK? I've read conflicting stories and one overclocking guide on this website says that Kaby Lake CPUs can be ran to 170 BCLK which seems really high considering previous generation CPUs couldent handle more than 104.

http://www.overclock.net/t/1621347/kaby-lake-overclocking-guide-with-statistics



"The higher you go from 100 base clock, the harder it is to stabilize. Generally the stability at 170 bclk and up will vary depending on the motherboard. You will sometimes fail to boot if the bclk is too high. There's usually no good reason to set the base clock above 170 though. With smart math, it should be possible to get very close to any frequency without exceeding 150 bclk."

Seriously, 170 BCLK? I cant see any reason to go over 103, because after that you can just use the multiplier to overclock... None the less, is this legit? Can the mobo really handle 150, because if it can then 101 is obviously perfectly fine.
 
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EarthDog

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Yes you can. Bclk limits will vary dramatically by board..id bet 150+ out of yours, sure.

Personally, i wouldnt bother.
 

trents

Senior Member
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Dec 27, 2008
How can you do this unless you have a modded bios or one of those boards with a clock gen chip, which I don't think there are any for the Kaby Lake generation. Apart from that, all I can get out of bclk increases are one or two ticks over 100 mhz before the system won't even boot.

Actually, I've never tried a significant bclk overclock on an k chip. Can you do this? I was thinking the PCI bus is still locked to the bclk even on the k chips or any CPU with IGP. I've overclocked with fsb/bclk on many older AMD and Intel CPUs without IGP.
 
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EarthDog

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The ones with the clockgen are good to a couple hundred bclk or more. Otherwise you should be able to get 150+...
 
OP
S

SPL Tech

Member
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Nov 28, 2006
So why is it that Z270 mobos can handle 150+ BCLK but Z170 and older mobos can only handle around 104 before they start crashing? I cant imagine the PCI-E bus changed that much from 170 to 270.
 

EarthDog

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There are z170 boards with and without bclk generators that can go way over that...they shouldnt hang at 104... ive had several at 200+ on ambient cooling. There are plenty of z270 with and without bclk gens that overclock well.. the asus apex says up to 400 mhz...

Pcie bus isnt attached!!!
 

trents

Senior Member
Joined
Dec 27, 2008
So I experimented with this concept this morning. I lowered my my overclock multipler a little and upped the BCLK by 10 mhz. I should have also lowered my RAM speed probably. Booted into Windows fine but then after a bit I got a blue screen so I set everything to UEFI defaults and rebooted and was still getting blue screens, message something about Kmode exception not handled. Researched this and found it's probably a driver issue as Whocrashed indicated it was as well. Did a fresh clean install of Windows and after Windows updates were added it started blue screening again, same issue. I ran 4 passes of memtest86 and the RAM checked out fine. Ran CrystaldiskInfo on the hard drive and no issues. I suppose it's just coincidence this happened in conjunction with my little bclk overclock experiment.

So I did a fresh clean install of Windows 10 once more but no Microsoft updates so far and it seems stable. One of those updates apparently has a buggy driver. Now got to figure out which one and which driver.
 

trents

Senior Member
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Dec 27, 2008
Its still attached to your memory..correct.

What is "it"? Not sure I understand your question.

Anyway, I reinstalled Windows one more time and restored my overclock from the bios profile I had created and all seems well now, even after all available Windows 10 updates were added back in.

I'm guess the oveclocked memory caused the first blue screen and that corrupted a driver.

The only reason I can imagine that I was still getting blue screens after putting everything in bios to default and doing a fresh clean install of Windows 10 was that some driver didn't install correctly.
 

EarthDog

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I didnt ask a question...that was a declarative statement. "It" is the bclk. Its still bclk x mem multi = mem speed. I was confirming what you were seeing/alluding to. ;)
 
OP
S

SPL Tech

Member
Joined
Nov 28, 2006
There are z170 boards with and without bclk generators that can go way over that...they shouldnt hang at 104... ive had several at 200+ on ambient cooling. There are plenty of z270 with and without bclk gens that overclock well.. the asus apex says up to 400 mhz...

Pcie bus isnt attached!!!
So what is all this stuff I read about PCI-E connected to BCLK and never go above 104 or you'll cook your SATA drives and mobo? I've seen that on tons of forums. So if PCI-E is not connected, what is? CPU, RAM, iGPU? what else?
 

EarthDog

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Sounds like advice for sandybridge amd ivybridge. But i believe ever since haswell or skylake, bclk doesnt affect pci bus. As i said earlier, It is attached to memory.
 

wingman99

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Dec 10, 2003
What is "it"? Not sure I understand your question.

Anyway, I reinstalled Windows one more time and restored my overclock from the bios profile I had created and all seems well now, even after all available Windows 10 updates were added back in.

I'm guess the oveclocked memory caused the first blue screen and that corrupted a driver.

The only reason I can imagine that I was still getting blue screens after putting everything in bios to default and doing a fresh clean install of Windows 10 was that some driver didn't install correctly.

I had a problem with playing with BCLK and reflashing the Bios twice fixed all the problems I was having.