z390, 9700k: can high BCLK (150+ Mhz.) cause instability?

[80251]

If you run a high BCLK (say 150+ Mhz.) would this cause instability all by itself? I've been experimenting w/a high BCLK to facilitate a higher FCLK.

 

[ir_cow]

Yes.

 

[Macro Device]

Of course. I don't know what exact numbers are on LGA1151 but anything higher than 170 MHz was considered voodoo on LGA1155/2011.

 

[80251]

Yes.

What I don't understand ir_cow is why does it matter? If I'm running the uncore/core/RAM at moderate overclocks why should it matter what BCLK they're running at?
If I run my 9700k at a 100Mhz. BCLK and 5000 core clock/4700 uncore/3900 RAM clocks and nearly the same core/uncore/RAM clocks at 150Mhz. BCLK, it can make a difference in stability?

 

[docnorth]

Usually you can increase baseclock up to 3%, in theory 103MHz, if I understand correct what you mean. You can check Intel locked CPU reviews, @W1zzard almost checks BCLK ‘overclocking’. I don’t know if unlocked CPUs have higher BCLK limits, except of course if the MB has an external BCLK generator.

 

[FreedomEclipse]

What I don't understand ir_cow is why does it matter? If I'm running the uncore/core/RAM at moderate overclocks why should it matter what BCLK they're running at?
If I run my 9700k at a 100Mhz. BCLK and 5000 core clock/4700 uncore/3900 RAM clocks and nearly the same core/uncore/RAM clocks at 150Mhz. BCLK, it can make a difference in stability?

Because BCLK also ties into different things on your system like memory speeds and PCI-E clock for instance and that could mess with things like storage or GPU. It puts the system out of whack thats why most overclocking is done by multiplier or tweaking the PBO if you're on AMD.

Its not like those days where you could increase both the multi and FSB at the same time for better clocks. Those days are long gone.



::EDIT::

Although I have seen after a quick google that some people have managed 150-180 BCLK on older Intel and AM4 platforms. Im not sure if they were just extremely lucky to pull it off or if it was 200% stable but you could find out more for yourself if interested.

 

[ir_cow]

I'm happy if 103 works lol

 

[Dr. Dro]

BCLK overclocking has long since been "dead", multiplier is heavily preferred because it stretches farther out and doesn't affect memory, bus timings, PCI clocks, etc. like base clock overclocking does.

50*100 is much preferred to 33.5*150 when targeting 5 GHz, for example.

 

[80251]

Aren't PCI clocks irrelevant now? You can adjust the memory speed independently of the BCLK though.

The only reason I was interested in an increased BCLK was so I could up the FCLK.

 

[natr0n]

I have a 9600k with gigabyte z390

I like doing 101.11 can go higher. I dont like seeing 99.99 so .11 is nice

you should play with other settings perhaps

 

[Toothless]

Aren't PCI clocks irrelevant now? You can adjust the memory speed independently of the BCLK though.

The only reason I was interested in an increased BCLK was so I could up the FCLK.

Throw it at 150 and see what happens. You'll answer your own questions.

 

[80251]

150+ Mhz. doesn't work, even at RAM/uncore/core clocks + voltages that work at lower BCLK -- unless it's the much higher FCLK that is causing the issue (1500+ Mhz. as opposed to 1000Mhz.), but I read that FCLK can hit 1600Mhz. without any issue.

 

[OneMoar]

150mhz? how tf is it even booting
103mhz max

 

[Toothless]

It's like what people have been telling OP..

 

[Mussels]

If you run a high BCLK (say 150+ Mhz.) would this cause instability all by itself? I've been experimenting w/a high BCLK to facilitate a higher FCLK.

Even 101 can cause instability.
it hasn't been since 1156 that i've seen bclk overclocking even work, so few motherboards have the ability to do it properly with a dedicated timing chip so it doesn't screw with everything on the board.

Varies massively by platform, too.

"Why does it matter?"
Because you're overclocking your PCI-E lanes too, and that can cause literally every component to crap out.

 

[Dr. Dro]

Aren't PCI clocks irrelevant now? You can adjust the memory speed independently of the BCLK though.

The only reason I was interested in an increased BCLK was so I could up the FCLK.

In most cases yes, but this can still affect older platforms. In general, you want to be doing your overclocks by multiplier, whenever possible.

 

[chrcoluk]

I agree with what the replies say, the scariest outcome of upping BCLK is corrupting your i/o storage data as you increasing the bus speed on the data pipe it runs over.

 

[damric]

Remember that these are Skylake refreshes, and thus the base clock is NOT tied to pci. So it's ok to raise as long as you keep your various multipliers in check.

However the Intel Management Engine should be keeping it from booting. Remember in 2016 Intel tried to block non-k skylake OC via bclk.

So what's going in here? Did Intel relax the microcode to allow bclk once again? If so, this is going to be very awesome for overclocking all of those non-k Lake CPUs.

 

[chrcoluk]

Might be they only blocked it on non Z chipsets and/or non K CPU's?

OP is using Z chipset with K CPU.

 

[damric]

Might be they only blocked it on non Z chipsets and/or non K CPU's?

OP is using Z chipset with K CPU.

They blocked it on all, asfaik. Like if I update my Z170, I wouldn't be able to base clock my Skylake i3 lol.

The thing that's weird of course, is that it was allowed again with Alder Lake, but then they blocked it again with Raptor Lake. And this is totally an artificial block. The last Intel CPUs that were actually bus-tied were Haswell, Ivy and Sandy.

So you shouldn't be able to do it, but if you can get around the artificial limit, DO IT

And when you run into a wall, it's most certainly memory timings in auto that need loosened. Example: if your memory is set to 3200 with auto/xmp timings, it's still going to try and use the 3200 timings even though you raised base clock by 50% and are running the RAM at 4800. I can explain how to do that better if you want later but I'm hardly awake right now.

 

[DR4G00N]

OP is using Z chipset with K CPU.

Yes, this allows BCLK oc just fine on 1151 and prior at least, IDK about 1200.

@80251 FCLK doesn't help much of anything, even going from 400MHz to 1GHz does practically nothing. If anything you'd want to lower it as BCLK oc'ing is usually better at 400MHz FCLK.

 

[80251]

@DR4G00N
An FCLK <= 800Mhz. causes noticeable stuttering w/my 4090. I believe anandtech did some testing w/FCLK and found that raising it increased 3dMark scores by a few percent, but that was w/a much less powerful GPU.

 

[Toothless]

That increase is not worth it if it stutters. Honestly just leave BCLK and FCLK alone before you really start messing things up.

 

[80251]

My apparent problems w/the high BCLK were all down to my Rosewill 750 Watt PSU, which couldn't handle an overclocked 9700k and a 4090. My ghetto mod of using two PSU (the 4090 gets its OWN PSU now)
is working.

The stutters occur if the FCLK is too low, not too high, right now my FCLK/system agent clock is at 1571 Mhz. without any apparent problems.

 

[Mussels]

Remember that these are Skylake refreshes

Not every motherboard handles it the same, is the key here.

Internally it's all dividers and multipliers - 100x8 for 800MHz (DDR3 1600) could then become 101x7.5 (757/1,515) or 808/1616 depending on how the board feels like doing things. Sometimes they change these in real-time too, with power saving mechanisms.

You then throw in that theres dividiers on just about every component, and 'not tied together' can still result in some decent swings - even GPU's work that way, my 'flat' undervolt curve on my 3090 has a 50MHz swing either way from what it's set to at times, as different dividers are used at different speeds invisible to the end user.