Intel launched this month their new CPUs based on the “Sandy Bridge” architecture. Let’s check the performance of the new Core i7-2600K (3.4 GHz) and compare it to the CPU it came to replace, the Core i7-875K (2.93 GHz), and to the most expensive CPU from AMD, the Phenom II X6 1100T (3.3 GHz).

For a detailed explanation of what is new in the Sandy Bridge architecture, please read our Inside the Intel Sandy Bridge Microarchitecture tutorial.

The new Core i7-2600K (3.4 GHz) is a quad-core CPU, coming in two flavors: with its clock multiplier unlocked (“K,” being the equivalent to the “Extreme Edition” CPUs Intel used to carry and to the “Black Edition” CPUs from AMD), giving you an extra way to overclock the CPU, and the standard model with a locked clock multiplier. The “K” model can be found today costing USD 330, while the standard model can be found for USD 300.

The Core i7-2600K comes with Hyper-Threading technology, meaning that the operating system recognizes eight CPUs, two per CPU core. Of course these extra “cores” are simulated.

We decided to compare the new Core i7-2600K (3.4 GHz) with the Core i7-875K (2.93 GHz), since both carry similar price tags.

The truth is that the new Core i7-2600K (3.4 GHz) has no direct competition. The most expensive CPU AMD currently has is the Phenom II X6 1100T (3.3 GHz), at USD 270, which is a six-core CPU. Therefore, throughout our review we will consider it as the Core i7-2600K’s main competitor, since no other CPU fits this spot.

CPU Cores HT IGP Internal Clock Turbo Clock Base Clock Core Technology TDP Socket Price
Core i7-2600K 4 Yes Yes 3.40 GHz 3.8 GHz 100 MHz Sandy Bridge 32 nm 95 W 1155 USD 330
Core i7-875K 4 Yes No 2.93 GHz 3.6 GHz 133 MHz Lynnfield 45 nm 95 W 1156 USD 340
Phenom II X6 1100T 6 No No 3.3 GHz 3.7 GHz 200 MHz Thuban 45 nm 125 W AM3 USD 270

TDP stands for Thermal Design Power which advises the user of the maximum amount of heat the CPU can dissipate. The CPU cooler must be capable of dissipating at least this amount of heat.

Prices were researched at on the day we published this review.

CPU L1 Cache L2 Cache L3 Cache Memory Support Memory Channels
Core i7-2600K 32 KB + 32 KB per core 256 KB per core 8 MB total DDR3 up to 1333 MHz Two
Core i7-875K 32 KB + 32 KB per core 256 KB per core 8 MB total DDR3 up to 1333 MHz Two
Phenom II X6 1100T 64 KB + 64 KB per core 512 KB per core 6 MB total DDR3 up to 1333 MHz Two

While all CPUs listed above have an integrated memory controller, only the new Core i7-2600K has an integrated graphics processor (IGP). Both the Core i7-2600K and the Core i7-875K have an integrated PCI Express 2.0 controller, handling 16 PCI Express lanes, allowing those CPUs to drive one PCI Express slot at x16 or two PCI Express slots at x8.

AMD CPUs talk to the external world (i.e. the chipset) thru a bus called HyperTransport. For a detailed explanation how this bus works, please read our The HyperTransport Bus Used by AMD Processors tutorial.

Socket LGA1156 and 1155 CPUs use the DMI (Digital Media Interface) bus to talk to the chipset, which is the interface previously used to make the connection between the north bridge and the south bridge chips on Intel chipsets.

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.