▷ Intel core i7 【all information】

What is Intel Core i7 and what are its characteristics

Intel Core i7 is a brand of Intel that applies to various families of desktop and laptop processors based on the x86-64 instruction set, using Nehalem, Westmere, Sandy Bridge, Ivy Bridge, Haswell, Broadwell, Skylake, Kaby Lake and Coffee Lake. The Core i7 brand targets high-end business and consumer markets for desktops and laptops, distinguishing itself from Core i3 (core consumer), Core i5 (core consumer), and Xeon (server and workstation).

Intel introduced the Core i7 name with the quad-core Bloomfield processor based on the Nehalem architecture in late 2008. In 2009, new Core i7 models based on the Lynnfield desktop quad-core processor, a slight evolution from Nehalem, and the Clarksfield mobile quad-core processor, also based in Nehalem, and models based on the mobile processor were added. Dual-core Arrandale in January 2010. The first six-core processor in the Core i7 line is Gulftown, also based on the Nehalem architecture, and was released on March 16, 2010.

In each of the brand's microarchitecture generations, Core i7 has family members using two different system-level architectures, and therefore two different sockets (for example, LGA 1156 and LGA 1366 with Nehalem). In each generation, the highest performing Core i7 processors use the same socket, and an internal architecture based on the technology of that generation mid-range Xeon processors, while the low-performance Core i7 processors use the same socket and architecture. internal than the Core i5.

Core i7 is a successor to the Intel Core 2 brand. Intel representatives stated that they intended to use the term Core i7 to help consumers decide which processor to buy.

Intel Turbo Boost

Intel Turbo Boost is Intel's trade name for a feature that automatically increases the operating frequency of some of its processors, and therefore their performance when performing demanding tasks. Turbo-Boost enabled processors are the Core i5, Core i7, and Core i9 series manufactured since 2008, more particularly those based on Nehalem, Sandy Bridge, and later microarchitectures. The frequency is accelerated when the operating system requests the highest performance state of the processor. Processor performance states are defined by specifying the Advanced Configuration and Power Interface (ACPI), an open standard compatible with all major operating systems; no additional programs or drivers are required to support the technology. The design concept behind Turbo Boost is commonly known as “dynamic overclocking”.

A technical report from Intel in November 2008 describes "Turbo Boost" technology as a new feature built into Nehalem-based processors released in the same month. A similar feature called Intel Dynamic Acceleration (IDA) was available on many Core 2-based Centrino platforms. This feature did not receive the marketing treatment given to Turbo Boost. Intel Dynamic Acceleration dynamically changed the core frequency based on the number of active cores. When the operating system instructed one of the active cores to enter the C3 sleep state using Advanced Configuration and Power Interface (ACPI), the other active cores were dynamically accelerated to a higher frequency.

When the processor workload demands faster performance, the processor clock will attempt to increase the operating frequency in regular increments as needed to meet demand. Increasing the clock frequency is limited by processor power, current, thermal limits, the number of cores currently in use, and the maximum frequency of active cores. Frequency increases occur in increments of 133 MHz for Nehalem processors and 100 MHz for Sandy Bridge, Ivy Bridge, Haswell and Skylake processors and later. When electrical or thermal limits are exceeded, the operating frequency automatically decreases in 133 or 100 MHz increments until the processor is again operating within design limits. T urbo Boost 2.0 was introduced in 2011 with the Sandy Bridge microarchitecture, while Intel Turbo Boost Max 3.0 was introduced in 2016 with the Broadwell-E microarchitecture.

One of the cool things that came up lately was the fact that Intel made a very clear change in policy when it comes to press release. When asked about the turbo per core values for each of the CPUs, Intel made a clear statement first, and then a secondary one when asked later:

“We are only including processor frequencies for single core and turbo base in our materials in the future; the reasoning is that turbo frequencies are opportunistic given their dependence on system configuration and workloads. ”

This change in policy is worrying and completely unnecessary. The information itself could be easily obtained by actually taking the processors and testing the required P states, assuming the motherboard manufacturer does no tricks, so this implies that Intel will retain information for arbitrary reasons.

However, you can get the turbo ratios per core for each of the new processors for a motherboard. Considering Intel's statement above, it seems to suggest that each motherboard could have different values for these, without Intel's guidelines.

For the most part, there is nothing out of the ordinary here. Intel uses base frequency as a guaranteed base under abnormal environmental circumstances and heavy code (AVX2), although in most cases, even the all-core turbo ratio will be higher than the base frequency.

What is Intel hyper-threading

Hyper-threading technology is Intel's simultaneous multi-process implementation (SMT), it is used to improve the parallelization of calculations, that is, to be able to perform multiple tasks at the same time, on x86 microprocessors. It first appeared in February 2002 on Xeon server processors and in November 2002 on Pentium 4 desktop CPUs. Later, Intel included this technology in Itanium, Atom and Core 'i' series CPUs, among others.

For each physically present processor core, the operating system targets two virtual (logical) cores and shares the workload with each other when possible. The main function of hyper-threading is to increase the number of independent instructions in the pipeline; leverages superscalar architecture, in which multiple instructions operate on separate data in parallel. With HTT, a physical core appears as two processors in the operating system, allowing the simultaneous programming of two processes per core. Also, two or more processes can use the same resources: if the resources for one process are not available, then another process can continue if its resources are available.

In addition to requiring simultaneous multithreading support (SMT) in the operating system, hyper-threading can be used appropriately only with an operating system specifically optimized for it. Additionally, Intel recommends that hyper-threading be disabled when using operating systems that are unaware of this hardware feature.

Intel UHD Graphics

The new Intel UHD graphics cores built into the Coffee Lake processors support HDCP2.2 on DisplayPort and HDMI, although an external LSPCon is still required for HDMI 2.0. The video outputs for Coffee Lake are similar to those for Kaby Lake, with three compatible display tubes for motherboard manufacturers to configure as needed.

Most Core i7 Coffee Lake processors will have Intel UHD Graphics 630 with 24 Execution Units. This graphics core is basically identical to the previous generation HD Graphics 630, except that now the name is UHD, which we assume is for marketing purposes now that UHD content and displays are more ubiquitous when naming first started.. The big major change is the addition of HDCP2.2 support.

Intel says there are performance improvements with the new graphics core, primarily from an updated driver stack, but also an increase in frequencies from the previous generation. Core i7-8559U is the only model that differs by integrating the Intel Iris Plus Graphics 655 graphics core, which is much more powerful thanks to the fact that it contains 48 Execution Units. Intel Iris Plus Graphics 655 also contains a small 128MB eDRAM cache, reducing the need for the graphics core to access system RAM, which is much slower than this eDRAM.

Current Intel Core i7 processors

Ten years have passed since Intel introduced quad-core Core i7 processors in its core product range. The six-core parts were expected to hit the segment a few years later, however due to process improvements, microarchitectural gains, cost, and lack of competition, the main processor in the consumer segment has remained a quad-core model for ten years.

Currently, we have the eighth generation Intel Core processors, also known as Coffee, with the Core i5 and Core i7 models that have finally made the leap to a six-core physical configuration after ten years. There are a number of interesting elements that will excite you in this release, and a number of factors that raise even more questions, to which we will refer. In this generation, the Core i7-8700K came in as the most powerful member with an impressive six-core, twelve-thread-processing configuration.

All new Coffee Lake desktop processors are socket processors for use on appropriate motherboards with 300 series chipsets, including the Z370, H370, B360, H310, and future Z390. Technically, these processors use the LGA1151 socket, which is also used by sixth and seventh generation processors with chipsets 100 and 200. However, due to differences in the pin design of these two processor sets., The eighth generation only works on 300 series motherboards as there is no cross compatibility level.

In previous generations, 'Core i7' meant we were talking about quad core processors with hyperthreading, but for this generation it is moving to a six core configuration with hyperthreadin g. The Core i7-8700K starts at a base frequency of 3.7 GHz and is designed to achieve a 4.7 GHz turbo in single-wire workloads, with a 95W thermal design power (TDP).

The K designation means that this processor is unlocked and can be overclocked by adjusting the frequency multiplier, subject to proper cooling, applied voltage, and chip quality. Intel only guarantees 4.7 GHz, so going from there is quite a lottery. The Core i7-8700 is the non-K variant, with lower clocks with a 3.2 GHz base speed, a 4.6 GHz turbo, and a lower TDP of 65W. Both processors use 256 KB of L2 cache per core and 2 MB of L3 cache per core.

When compared to the previous generation, the Core i7-8700K came in at a higher price, but for that price it offers more cores and a higher operating frequency. The Core i7-8700K is a good example of how core aggregation works, because to maintain the same power consumption, the overall base frequency must be lowered to match the presence of additional cores. However, to maintain higher responsiveness than the previous generation, single-threaded performance is typically tuned to a higher multiplier.

Below the Core i7 we have the Core i5 processors, which maintain the same core configuration, but without hyperthreading, so they only offer six processing threads. The Core i5s operate at lower clock speeds compared to the Core i7, especially with the Core i5-8400 having a base frequency of just 2.8 GHz. When comparing cache sizes with the Core i7, the Core i5s have the Same L2 setting at 256KB per core, but have L3 reduced to 1.5MB per core as part of product segmentation.

It is interesting to note that in the past few generations, Intel had quad-core processors with hyperthreading, leading to a quad-core, eight-threading configuration. With the move to 6-core and 12-thread on the high-end Core i7 and 6-core and 6-thread on the mid-range Core i5, Intel completely bypasses the 4-core and 8-thread configurations, and moves directly to 4-core and 4 threads on the Core i3. This is likely because a 4-core, 8-thread processor could overtake a 6-core, 6-thread processor in some performance tests.

The following table summarizes the features of current Intel Core i7 Coffee Lake desktop processors:

Intel Core i7 Coffee Lake for desktop
	Core i7-8086K	i7-8700K	i7-8700
Cores	6C / 12T
Base frequency	4	3.7 GHz	3.2 GHz
Turbo boost	5	4.7 GHz	4.6 GHz
L3 Cache	12 MB
Memory support	DDR4-2666
Integrated graphics	Intel UHD Graphics 630
Graphics base frequency	350 MHz
Graphics Turbo Frequency	1.20 GHz
PCIe Lanes (CPU)	16
PCIe Lanes (Z370)	<24
TDP	95 W	65 W

The following table summarizes the characteristics of the current Intel Core i7 Coffee Lake processors for laptops:

Intel Core i7 Coffee Lake for Laptops
	Core i7-8850H	i7-8750H	i7-8559U
Cores	6C / 12T	4/8
Base frequency	2.6	2.2 GHz	2.7 GHz
Turbo boost	4.3	4.2 GHz	4.5 GHz
L3 Cache	12 MB	8 MB
Memory support	DDR4-2666	DDR4-2400
Integrated graphics	Intel UHD Graphics 630	Intel Iris Plus Graphics 655
Graphics base frequency	350 MHz	300 MHz
Graphics Turbo Frequency	1.15 GHz	1.2 GHz
TDP	35 W	28W