arges86 :
they are exactly the same, accept that the 4770k is an unlocked chip, which allows you to overclock,
if you compare these two pages, you see they are nearly identical
http://ark.intel.com/products/75123/ & http://ark.intel.com/products/77656
Since people asked how they were different, I'll provide some more detail... As previously mentioned, the main difference is that the "k" chips are designed for enthusiasts & overclockers, and so they are unlocked. The 4771 is designed for a cloud/server environment and has special technology built into the chip for this purpose. Those technologies are:
1. Intel® Virtualization Technology for Directed I/O (improves hardware performance in virtual environments.)
2. Trusted Execution Technology TXT (addresses a security hole in cloud based systems.)
3. Intel® vPro Technology (great security features)
4. Intel® TSX-NI (increases performance for parallel operations)
The 4770k lacks these technologies. For your average enthusiast home user, these technologies won't be missed unless you run a virtual OS or have security concerns. If your worried about someone hacking your BIOS/Firmware or installing some other nefarious device on your system, TXT should recognize the change, and prevent the system from booting. If your upgrading your firmware and BIOS a lot, TXT might actually cause you some security headaches.
The vPro technology might be the biggest sacrifice you make by going with a "k" chip. Who isn't concerned with security? Intel describes it like this: "1) Threat management, including protection from rootkits, viruses, and malware 2) Identity and web site access point protection 3) Confidential personal and business data protection 4) Remote and local monitoring, remediation, and repair of PCs and workstations."