BLCK Straps Section:
First we have to realize that SBe also has BLCK overclocking. SB also had slight BLCK overclocking; the base frequency of 100 MHz could be OCed 5-7%. The same thing is possible with SBe, so you could look at 106-107 MHz BLCK on average. The issue with going higher is that the BLCK is now tied to the PCI-E bus and DMI. You can corrupt your OS and your GPUs by increasing the BLCK too much. Otherwise the CPU also won’t want to do it either. So Intel introduced BLCK straps, multipliers really, at 1.00(stock), 1.25, 1.67, and 2.5.

So final CPU frequency = CPU Multiplier X BLCK X BLCK Strap.
Memory Frequency= Memory Multiplier X BLCK X BLCK Strap

Since the memory frequency is also tied to the BLCK Strap you need to pay attention to it. Most users will just OC with 1.00 BLCK Multiplier, as it is easier. BLCK straps of course let you use frequencies like 2000 MHz memory speed that previously were very hard/impossible to produce. Also the BLCK multipliers don’t really increase performance, how do I know? Well I tested it. I asked myself the question, “at what frequency can I use the 1.00 and 1.25 multipliers, but also have the same memory and CPU frequency?” Answer: 4.00 GHz CPU and 1333 MHz Memory, here were my results:


It seems that the BLCK straps are virtual. They do however offer the benefit of hitting frequencies that cannot be done with stock multipliers. For instance if you want to get 2000 MHz memory, you have to use a strap.

Here are some Tips:

  • Remember to LOWER CPU and MEMORY Multipliers after changing BLCK Straps!!!!!!
  • Set the Straps/multiplier for the BLCK BEFORE changing other settings.
  • VCore Helps with higher BLCK, you can also try VTT.
  • 1.67 multiplier is very hard to use with 100.00mhz BLCK, to use this multiplier you should try 90.00mhz BLCK and then change the multiplier to 1.67, that will give you 150mhz BLCK. Then work your way up. A very small percentage of CPUs can do 100x1.67.
  • CPU Switching Frequency can slightly help BLCK, I saw no affect though.
  • Changing the BLCK or Straps in BIOS WILL require a reboot of the system, so keep that in-mind when OCing.
  • It might be easier to hit higher memory frequencies with the 1.25 strap than 1.00, but I saw no difference in ease.
  • If you are having trouble hitting 1.67, first try 1.00x90.00, than try 1.25x90.00, then try 1.67x90.00
  • Disabling C States might help
  • Increasing memory frequency slightly might help


My Examples:
5GHz WITH 1.25 Strap. So with straps you use lower CPU Multiplier and Memory Multiplier.

How about 132.5mhz BLCK?

Here is my max BLCK with 1.00, that is stable (it required increased VCore):