Question Overclocking of Non K Intel CPUs on Z270 Chipset - Success Single Time Only!??

[Moochiek]

Hi.

I'm trying to find out how it was possible to get a stable Overclock of a Non K Intel i5-6500 CPU on MSI Z270 SLI Plus motherboard (at 4.1GHz) only for for the motherboard to just ignore the settings with all subsequent reboots and changes to the BIOS.

Did anyone experience this? I would understand if it didn't work from the start but I ran CPU-Z and my BCLK was at 130MHz and Benchmark was higher than i5-7600K, stress test running for 20 minutes. The computer went into a sleep mode after inactivity and would not wake from it. Once I shut down the computer and booted up again, back to 3.2GHz default. BIOS settings still showing all the changes I made to BCLK, CPU voltages, RAM speed etc but also showing CPU running at 3.2GHz and memory at default.
I used latest 2018 BIOS from MSI site. I thought maybe going back to the very first BIOS will allow overclock but no, same things, BIOS ignoring any BCLK settings.
According to searches I made, it seems the overclock should not be possible. How did it work at all?

If anyone has a logical explanation, I would like to hear it. I'm thinking the BIOS may have registered failed overclock and keeps it in some kind of log?

Thanks.


Intel i5-6500 3.2GHz CPU
MSI Z270 SLI Plus (original BIOS version right now)
MSI GTX 1070 Ti Armor
Corsair 16GB DDR4 (single stick, I know) 2400MHz
Toshiba 1TB SSD

PS: Would UEFI have any way of interfering?

 

[Barty1884]

A 130 BCLK? I'm stunned that would even boot.

I'm thinking it was unstable, and the BIOS reset? Maybe...

 

[Moochiek]

Thanks, the OC seems pretty standard according to guides on Youtube (with Z170 boards) and I have a pretty good watercooler. The OC only affects the CPU and memory, which was running slightly bellow it's speed.
I keep reading about Windows 10 updates disabling the OC, it's possible as I switched from a B250 motherboard without reinstalling Windows and perhaps not all drivers were installed for the Z270 board when I OCed.

 

[Barty1884]

Hmm, odd. I haven't heard of a BCLK being able to go that high in years - but looking it up, people are suggesting that for a 6400, so would assume possibel on a 6500 too.

I know at one point (~Skylake launch), non-K CPUs were able to be OC'd, but that functionality was removed with a BIOS update and you could not roll back from it - if a board was updated, it was updated.

Doesn't sound like that's what happened here though? The BIOS doesn't 'lock in' the settings BEFORE you attempted updating the BIOS?

 

[Moochiek]

Hmm, odd. I haven't heard of a BCLK being able to go that high in years - but looking it up, people are suggesting that for a 6400, so would assume possibel on a 6500 too.

I know at one point (~Skylake launch), non-K CPUs were able to be OC'd, but that functionality was removed with a BIOS update and you could not roll back from it - if a board was updated, it was updated.

Doesn't sound like that's what happened here though? The BIOS doesn't 'lock in' the settings BEFORE you attempted updating the BIOS?

What is happening is I set the OC settings, computer reboots with no OC fail (which does come up when I try something different than guides) and happily goes to Windows but all CPU settings are standard. When I go back to the BIOS, CPU runs at default 3.2GHz but OC settings show the BCLK overclock and all adjustments. I have to go to load defaults to change the OC settings to defaults.

Again, the one explanation might be that not all hardware changes were done when switching motherboards (from B250 to Z270). Still disappointing. Now I have to look for a Z170 motherboard that will take old BIOS to overclock. There is a list online with downloadable BIOS files for the Z170.
If I have time, I may try older version of Windows 10 and see if the OC will stick.

 

[Darkbreeze]

Overclocking in that manner is pointless and probably harmful to the rest of the system anyhow, since everything else uses the BCLK such as the PCI bus, USB bus, etc., and none of that is intended to be overclocked. Even so, I'd try this FIRST, and see if you can reconfigure and get settings to stick if you still wish to do so. A hard reset should resolve the hardware table issues you are currently seeing.

Power off the unit, switch the PSU off and unplug the PSU cord from either the wall or the power supply.

Remove the motherboard CMOS battery for five minutes. During that five minutes, press the power button on the case for 30 seconds. After the five minutes is up, reinstall the CMOS battery making sure to insert it with the correct side up just as it came out.

Now, plug the power supply cable back in, switch the PSU back on and power up the system. It should display the POST screen and the options to enter CMOS/BIOS setup. Enter the bios setup program and reconfigure the boot settings for either the Windows boot manager or for legacy systems, the drive your OS is installed on if necessary.

Save settings and exit. If the system will POST and boot then you can move forward from there including going back into the bios and configuring any other custom settings you may need to configure such as Memory XMP profile settings, custom fan profile settings or other specific settings you may have previously had configured that were wiped out by resetting the CMOS.

 

[Moochiek]

Darkbreeze, thanks for the info. The only thing that is wrong in your post is the effect of BCLK on PCI-E bus etc. It does not have effect on those chipsets, it only affects RAM and the BIOS anticipates that and allows choice of RAM speed at or bellow its speed.
I did do the battery removal process, just too busy today to try overclocking.

 

[Darkbreeze]

Maybe, I know it was uncoupled at some point but I thought it was an all in or nothing except for the core clock on Z270. Perhaps not. Still, gains from BCLK are generally minimal and usually don't offer enough to be worth it in most cases anyhow. But to each his own. I tend to overclock all my systems, but I buy unlocked skus as well, so I understand the desire to eek out whatever you can get.

 

[TJ Hooker]

It does not have effect on those chipsets, it only affects RAM

FYI, BCLK also affects FCLK and cache frequency, in addition to core clock and RAM.