My buddy and I are bored, trying to mess around with BCLK OC'ing.

Okay, so to kill some time and as a fun little side project, a buddy of mine brought a basic home theater PC over to me to see what all we could do with a locked CPU (i5-4460) as far as BCLK OC'ing. It has an ASRock Pro3 board, same as mine, and yet I've no idea what to do here as for voltage. I've seen BCLK OC guides online saying if you give it some voltage, Haswell and Skylake can be OC'd via BCLK even if they have a locked multiplier. We located the Vcore voltage setting, and as you'd expect it's on auto. BIOS says we can go as low as .8V or as high as 2V, but gives no info on the default voltage. Just wondering if there even is such a thing, or if the system just fluctuates the voltage as needed automatically. We were afraid to mess with anything without knowing where we were starting from, so I figured a quick post to the forums could help clear things up.

Regardless of additional voltages, most boards will be limited to ~103MHz bclk. On some "overclocking" motherboards you can set it a bit higher but I wouldn't expect more than ~105-107MHz.

Well the whole reason he wanted to try it is because he showed me a video of a guy getting to 4.2GHz on an i5-6500 with just BCLK. Figured it might not be possible on Haswell though.

Vishera said:

Well the whole reason he wanted to try it is because he showed me a video of a guy getting to 4.2GHz on an i5-6500 with just BCLK. Figured it might not be possible on Haswell though.

Click to expand...

You cant oc haswell with BLCK, cause its connected to the PCI and RAM slots and will oc them too of you set the BLCK higher(oc). Skylake mobos has different chipset "architecture" and the BLCK is connected only to the CPU so you can set the BLCK higher and it will oc the CPU only. Dont try it unless you want to damage your board and RAM and everything connected to the PCI slot.

Indeed. If that system has an SSD forget it. Higher than norm (100Mhz) BCLK kills SSD's. If it doesn't though, OS corruption will eventually happen. That said I was running 108Mhz BCLK on my i5 2300 stable for a month. It can be done, but not worth the risk for 3 extra Mhz.

*Note that I was running Sandy Bridge NOT Haswell!*

Get yourself an AsRock the earlier BIOS allowed BCLK adjustments to your hearts desire. The AsRock Z170-Pro4 is a affordable and quality board. Side note your board might to just roll back the BIOS past one that has Skylake OC removed.

Silver_Pharaoh said:

Indeed. If that system has an SSD forget it. Higher than norm (100Mhz) BCLK kills SSD's. If it doesn't though, OS corruption will eventually happen. That said I was running 108Mhz BCLK on my i5 2300 stable for a month. It can be done, but not worth the risk for 3 extra Mhz.

*Note that I was running Sandy Bridge NOT Haswell!*

Click to expand...

SSD actually like higher bclk/pcie than HDD. On boards that let you OC bclk/pcie you can make up to 115-120MHz pcie and SSD will still run fine. That of course depends from series but it's my general experience while benching. For example on AMD Kabini I was able to push pcie up to 130MHz and I was able to run benchmarks. Some other devices will give up faster like graphics cards or audio cards.

I think that bclk limit is till some point just "fake" limit made by Intel. Look how unlocked chips are working. Nearly every K CPU on good overclocking board can make 107-112 bclk. On the same board nearly every Pentium or i3 can make max ~103-104MHz. Xeons also can't make more than ~103Mhz bclk.

Safe limit is about 103MHz. Above that as I mentioned some devices won't work but I haven't heard about any damaged hardware because of bclk overclocking. On the other hand 3% OC is like nothing so I'm not sure if there is even point to make it.

Oh. I was told that SSDs just weren't as reliable as spinners with high BCLK...

That was years ago when SSDs were the latest thing so that's probably why. They were still very new and at that point in time. Probably still buggy/unreliable.

OptyTrooper said:

Get yourself an AsRock the earlier BIOS allowed BCLK adjustments to your hearts desire. The AsRock Z170-Pro4 is a affordable and quality board. Side note your board might to just roll back the BIOS past one that has Skylake OC removed.

Click to expand...

Its a skylake supporting board not haswell.

M@rk said:

Its a skylake supporting board not haswell.

Click to expand...

I know there are bios that allow BCLK over clocking for skylake. Case in point. http://www.overclockers.com/forums/showthread.php/770763-Pentium-G4400-5103-09

You are right, but the OP is using Haswell, not skylake. His CPU won't work in a Z170 board.