K stands for Unlocked
Intel has finally realized that unlocking some CPUs completely is not a bad idea and it looks like it's planning to introduce some new completely unlocked CPUs.
In the first days of June Intel plans to release Core i7 875K, which will be the first unlocked socket LGA1156 CPU. It fits on P55 powered motherboards and it is overclocking enabled CPU.
This means that this CPU will allow full control over the processor frequency ratio for the best possible overclocking results. The TDP of this CPU is 95W and your board will need a bios update to work. It's a quad-core CPU with Turbo Boost and dual channel DDR3 1333 memory support.
We don’t know the exact frequency but we believe that it should be close to 3.0GHz, simply as Core i7 870 works at 2.93GHz. So the logic is quite sound, when you see the K suffix, it will mean that you are getting the completely unlocked CPU.
Subject: core I7 unlocked multipliers 
Mon Mar 22, 2010 11:58 pm
