The Skylake Architecture

The Skylake Architecture

We'll address some key aspects and a technical overview of the technology and architecture first. Chances are good that you already have learned about this information over time. Right lets step back a few generations and start at Sandy Bridge at 32 nm. Sandy Bridge really was a completely new architecture, its successor Ivy Bridge did share a lot of common denominators. When we look at Sandy versus Ivy Bridge, the foremost complicating factor was moving the architecture towards a smaller production node; Ivy Bridge is a 22 nm processor series. Haswell then, is a 22 nm product yet based on a FinFET process that uses a non-planar transistor that sits around the gate on three sides. Built using a 22 nm process, Haswell is the "tick" in Intel's "tick-tock" development cycle, so Ivy Bridge was just a process size shrink from Sandy Bridge's 32 nm to 22 nm.

Then a jump to 14 nm, Broadwell is a Tick in the release schedule to be followed by a Tock, Skylake. For Skylake several things changed, an increasingly more powerful graphics engine and that fabrication shrink at the 14 nm node, this allows for an even more power friendly processor. The 5^th generation processors there will of course be a distinction 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 8 MB L3 cache
• Desktop Core i5 processors have four cores / NO hyper-threading / Up to 6 MB L3 cache
• Desktop Core i3 processors have two cores (unannounced)

A lot of processors will be based on Skylake, the desktop side are actually the Skylake-S series, Skylake-Y series would power the Core M based processors for ultra low TDP devices, Skylake-U processors will be mainstream mobility devices and Skylake-H series are the high-end, performance focused mobility chips that will include both regular HQ variants along with Xeon processors for consumers demanding extra workstation capabilities on developer notebooks. But we focus on desktop, lets have a closer look.

Core Core i5-6600K and i7-6700K

Both models are quad-core processors based on the aforementioned Skylake architecture and supersedes the Core i7-4770 / 4790 processor range (in design). The Core i7 model has hyper-threading and your OS will see it as an 8-core products. The CPU has 1 MB L2 cache (256 kB per physical core). Then there is a 8 MB shared L3 cache. The integrated memory controller remains dual-channel, officially supporting up-to 2,133 MHz, but we all know how high these puppies can clock. The TDP for this processor is 65 Watts. The Core i5 model is fairly similar product, yet clocked a notch slower at a 3.5 GHz base clock and 3.9 Turbo allowance. This processor as stated does not have hyper-threading. Also it has slightly less L3 cache at its disposal, 6 MB.

Core i7 6700K - 4 cores and Hyper-Threading, 4.0 GHz frequency, 4.20 GHz maximum Turbo Boost frequency, 8 MB last-level cache, dual-channel DDR3/DDR4 memory controller with 1,600 MHz or 2,133 MHz support, Intel HD Graphics 5000-series integrated graphics core, LGA1151 packaging

Core i5 6600K - 4 cores, 3.50 GHz frequency, 3.90 GHz maximum Turbo Boost frequency, 6 MB last-level cache, dual-channel DDR3/DDR4 memory controller with 1,600 MHz or 2,133 MHz support, Intel HD Graphics 5000-series integrated graphics core, LGA1151 packaging;

There will be more varyants available though:

The Skylake cache memory consists of a 32 KB L1 Data cache, 32 KB Instruction cache (= 64 KB L1) and then we spot a 256 KB L2 cache per core (1 MB total) and then there's a L3 cache that is shared in-between the CPU cores which is 8 MB in total for the Core i7 processors and 6 MB for the Core i5 series. 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. You can house the new Skylake processors on motherboards with the H170 and Z170 chipset, later on other business orented chipsets will be introduced as well. So no, the H97/Z97 chipset is not compatiable! For end consumers like you and me the H series chipset is less performance targeted and comes with better support for HTPC monitor connectivity. The Z series chipset is targeted at performance and enthusiast end users allowing much more tweaking and providing performance features. It also brings USB 3.1, SATA Express and PCIe M.2 SSD connectivity to the platform. 

CPU	Core i7-5775C	Core i5-5675C	Core i7-6700K	Core i5-6600K	Core i7-4790K	Core i7-4770K
Codename	Broadwell	Broadwell	Skylake	Skylake	Haswell	Haswell
Package	LGA1150	LGA1150	LGA1151	LGA1151	LGA1150	LGA1150
Cores/threads	4/8	4/4	4/8	4/4	4/8	4/8
Frequency（GHz）	3.3-3.7	3.1-3.6	4.0-4.2	3.5-3.9	4.0-4.4	3.5-3.9
memory	DDR3-1600	DDR3-1600	DDR4-2133	DDR4-2133	DDR3-1600	DDR3-1600
IGP	Iris Pro 6200	Iris Pro 6200	Intel HD 530	Intel HD 530	Intel HD 4600	Intel HD 4600
L3 Cache	6MB	4MB	8MB	6MB	8MB	8MB
Fab	14nm	14nm	14nm	14nm	22nm	22nm
Unlocked multiplier	Yes	Yes	Yes	Yes	Yes	Yes
TDP	65W	65W	92W	92W	84W	95W