Core i5 2500K and Core i7 2600K review - Meet the Sandy Bridge Architecture

Meet The Sandy Bridge Architecture

Sandy Bridge really is a completely new architecture. The overall processor performance, really, is going to stagger you. And inside the die, merged deeply in there, we spot an integrated GPU (I really like to call it a video processor though), with twice the performance of the last generation we saw from Clarkdale processors. By itself that's still not a lot, but it definitely is an improvement in the low-end segment. There's more though, we see the new AVX instruction set extension which is really gonna help out in say transcoding matters, we spot an updated Turbo engine allowing much more efficient per core performance and clock frequencies, we notice really good power consumption especially in idle, we spot new chipsets and well... it's just a lot to digest, so let's go through some of the more important aspects point by point.

What is Intel releasing?

Intel today releases the next (2nd) generation Core i3/i5/i7 processor family. Though today is all about the Core i5 2500K and Core i7 2600K processors, there will be a huge lineup in the months to come, below you can see a small overview of what you can expect based on this new architecture for desktop processors:

Desktop Core i7 processors: i7-2600K, i7-2600S, i7-2600
Desktop Core i5 processors: i5-2500K, i5-2500S, i5-2500T, i5-2500, i5-2400, i5-2400S, i5-2390T, i5-2300
Desktop Core i3 processors: i3-2120, i3-2100, i3-2100T

Paired with these processors come new motherboard chipsets, ten in total of which five are intended for desktop processors, namely the P67, H67, Q65, Q67, and B65. For end consumers like you and me the H67 chipset will be less performance targeted and comes with support for monitor connectivity. The P67 chipset is targeted at performance and enthusiast end users allowing much more tweaking and providing performance features. In the coming weeks we'll be testing a lot of these chipset based motherboards, of which some will now also have support for the new UEFI BIOS. A graphics user interface BIOS that is going to astound you.

Sandy Bridge architecture

Whereas the previous Clarkdale processors had a 45nm GPU and a 32nm CPU core placed onto one chip package, the new Sandy Bridge architecture comes together and merges these two parts on the die, all based on a 32nm fabrication node.

SB (Sandy Bridge) Core i5 and i7 based processors will have four physical (execution) CPU cores each capable of one hyper-thread (making 4 physical cores and 8 logical cores hyper-threaded), they include integrated graphics and a memory controller. Like other 1st generation Nehalem derivatives, SB will feature Intel Turbo Boost which has been further developed and is now at revision 2.0.

For the Sandy Bridge generation there will of course be a distinctions per processor segment (i3/i5/i7). What you get in terms of features and what you need to remember limitation wise:

• Desktop Core i7 processors have four cores / eight hyper-threads / Up to 8MB cache
• Desktop Core i5 processors have four cores / NO hyper-threading / Up to 8MB cache
• Desktop Core i3 processors have four cores / NO hyper-threading / Up to 3MB cache

All models will come with a respective Turbo mode though but only the Core i7 series will be capable of handling two independent software threads per core, hyper-threading. It's a feature we like very much as it really helps out on peak performance, it allows a processor to execute two different code streams at pretty much the same time.

The Core i7 SB processors feature 8MB of Intel Smart Cache and an Integrated Memory Controller (IMC) that supports two-channels of DDR3 memory at officially supported speeds of up to 1333MHz. Core i5 and i3 will have small L3 caches, 6MB.

I've created a nice table where you can observe all primary specifications and prices, have a good look.

As you can see, there will also be a 2400 model and later on even more, you will also spot S models like the Core i7 2600S, these all have a lower TDP (65W) but also come with a lower base clock frequency (2.5 GHz for the 2400S, 2.7 GHz for the 2500S and 2.8 GHz for the 2600S).

If you go a little deeper into the core then your first question will be, what about L1 and L2 caches? The Sandy Bridge cache memory consists of a 32KB L1 Data cache, 32KB Instruction cache (= 64KB L1) and then we spot a 256KB L2 cache per core. Then there's a nice L3 cache that is shared in-between the CPU cores which is 8MB in total for the Core i7 2600 processors and 6MB for the Core i5 2500. The L3 cache is where the magic happens, surrounding the segments inside the die, the L3 cache sits in the physical form of a ringbus. Thus the L3 cache can be used by the processor cores and also the graphics core.