Bclk adjustment

[Be1n]

If my ivy bridge motherboard is running at 99.8mhz, is it safe to move it up to 100.2mhz? Otherwise the processor and ram would be slower than stock.

Thank you.

 

[ViRGE]

Does your board even allow such a fine adjustment? 99.8MHz is 0.2% below the spec, and is quite likely within the allowed variance. I'm not sure it's worth the time to even address it.

 

[ShintaiDK]

Its part of the spectrum changes isnt it. For EMI.

So that behaviour is actually stock.

 

[Magic Carpet]

If my ivy bridge motherboard is running at 99.8mhz, is it safe to move it up to 100.2mhz? Otherwise the processor and ram would be slower than stock.

Thank you.

Move it up to about 105 Mhz. Shouldn't affect system stability and give you a bit faster processor, completely free of charge

 

[Ben90]

Not sure about newer boards, but when Sandy came out 105 was definitely starting to push the boundaries of stability. For a set and forget without testing anything higher, I wouldn't recommend 105.

 

[pantsaregood]

I don't recommend BCLK overclocking. Even when it doesn't cause crashes, it can lead to sorts of "silent" instability.

That said, there have always been boards that have issues running at the proper BCLK (or older analogs of it), and adjustments to "correct" this shouldn't lead to any issues.

My i5-2500K defaults to a BCLK of 99.8 MHz if I use the stock BIOS on my GA-Z68A-D3-B3, and 100.2 MHz if I use the UEFI upgrade Gigabyte provided.

My mom's Athlon 64 X2 runs at 198 MHz "BCLK."
My aunt's Pentium 4 has FSB stuck at 131 MHz, rather than 133 MHz.

 

[Magic Carpet]

I don't recommend BCLK overclocking. Even when it doesn't cause crashes, it can lead to sorts of "silent" instability.

Like not adding up numbers correctly, 4 + 4 = 6?

I want to experience that

 

[Puppies04]

Move it up to about 105 Mhz. Shouldn't affect system stability and give you a bit faster processor, completely free of charge

105 is getting very close to the point where it won't even boot on some chips, advising someone to do this and risk silent data corruption is completely irresponsible.

 

[Magic Carpet]

105 is getting very close to the point where it won't even boot on some chips, advising someone to do this and risk silent data corruption is completely irresponsible.

Again, I would appreciate if you could suggest how to diagnose "silent data corruption" with only 5% BCLK OC. Real example please.

 

[Puppies04]

Again, I would appreciate if you could suggest how to diagnose "silent data corruption" with only 5% BCLK OC. Real example please.

You diagnose it when your files become unreadable or your system fails to boot. As I said, you can pretty easily make any SB/IB system fall to its knees with around 106-108 BCLK (some are higher or lower depending on the chip lottery) so blindly advising someone to just set it at 105 is irresponsible.

 

[Puppies04]

Again, I would appreciate if you could suggest how to diagnose "silent data corruption" with only 5% BCLK OC. Real example please.

You diagnose it when your files become unreadable or your system fails to boot. As I said, you can pretty easily make any 1155 system fall to its knees with around 106-108 BCLK (some are higher or lower depending on the chip lottery) so blindly advising someone to just set it at 105 is irresponsible.

 

[toyota]

leave it alone or turn off spread spectrum for 100.

 

[Magic Carpet]

You diagnose it when your files become unreadable or your system fails to boot.

You can have these problems running everything at stock, as well. I thought, maybe you had an internal Intel tool, you wanted to share :whiste:

As I said, you can pretty easily make any 1155 system fall to its knees with around 106-108 BCLK (some are higher or lower depending on the chip lottery) so blindly advising someone to just set it at 105 is irresponsible.

Most Ivy Bridge builds I have assembled have been safely running with ~105Mhz BCLK.

Please come forward whoever damaged his/her computer and / or lost data using BCLK 105 or less.

 

[Borealis7]

speaking of BCLK tuning, what do you think will be more stable for Haswell - BCLK or Multi OCing?
because i assume there is no chance the cpu would run on 166MHz BCLK on stock voltage, and setting that BCLK is the equivilant of a x55 multiplier on a 4770K.
i can't imagine the voltage needed for that to work properly!

 

[pantsaregood]

The problem isn't that 5% is a huge overclock, it is that the base clock of Sandy Bridge/Ivy Bridge controls a large host of components, and modifying it slightly can cause them to go out of sync dramatically.