The differences between the Intel® Core™ i5-2500K and the Intel Core i5-2500 come down to just a couple things.
Intel Core i5-2500:
-Support for TXT (Trusted Execution Technology)
-Support for VT-d (virtualization directed I/O)
-Intel HD 2000 Graphics
Intel Core i5-2500K:
-Unlocked multiplier (allows overclocking of the processor)
-Intel HD 3000 Graphics
Now there is about a $ 15 dollars price difference between these processors and with the better graphics for back up the value for the Intel Core i5-2500K is still thought to be worth more than the $15 even if you don’t overclock.