Intel Core i7-8700 vs Intel Core i7-6820HQ vs Intel Core i7-6870HQ

Intel Core i7-8700

The Intel Core i7-8700 is a high-end desktop processor with six cores based on the Coffee Lake architecture and was announced in September 2017. The processor clocks at between 3.2 and 4.6 GHz and can execute up to twelve threads simultaneously thanks to Hyper-Threading. According to Intel, the CPU is manufactured in an improved 14nm (14nm++) process. Compared to the slightly higher clocked Core i7-8700K, the i7-8700 offers a lower TDP and no unlocked multiplier (no easy overclocking).

Performance

Due to the two additional cores, performance has increased by almost 50% compared to the previous quad-core Kaby Lake models. Single-core performance has not improved much. As a high-end model, the i7-8700 is suitable for the most demanding applications and games.

Graphics

The integrated Intel UHD Graphics 630 iGPU is supposed to offer higher performance as its clock rate has been increased by 50 MHz. The build is identical to that of the Intel HD Graphics 630. We do expect a performance improvement, but as a low-end solution it will probably only display current games smoothly at reduced details - if at all.

Power Consumption

Intel specifies the TDP with 65 watts. Therefore, well-dimensioned cooling systems should easily manage to deal with the created heat. We expect increased efficiency due to the higher performance.

Intel Core i7-6820HQ

The Intel Core i7-6820HQ is a quad-core processor based on the Skylake architecture, that has been launched in September 2015. In addition to four CPU cores with Hyper-Threading clocked at 2.7 - 3.6 GHz (4 cores: max. 3.2 GHz, 2 cores: max. 3.4 GHz), the chip also integrates an HD Graphics 530 GPU and a dual-channel DDR4-2133/DDR3L-1600 memory controller. The CPU is manufactured using a 14 nm process with FinFET transistors.

Compared to the very similar Core i7-6820HK, the Core i7-6820HQ supports additional administration and security features like Intel vPro and TXT, but lacks the unlocked multiplier for OC.

Architecture

Skylake replaces both Haswell and Broadwell and brings the same microarchitecture in every TDP class from 4.5 to 45 W. The extensive improvements of the Skylake design include increased out-of-order buffers, optimized prefetching and branch prediction as well as additional performance gains through Hyper-Threading. Overall, however, performance per clock has been increased by only 5 to 10 percent (compared to Haswell) respectively under 5 percent (compard to Broadwell), which is quite modest for a new architecture ("Tock").

Performance

Thanks to the improved architecture, the Core i7-6820HQ performs roughly on par with the former Core i7-4900MQ (Haswell) or the Core i7-5700HQ (Broadwell). Under long-lasting full load, the Skylake chip will take the lead over most of its Haswell-based predecessors, as the advanced 14 nm process leads to a higher energy efficiency and reduces throttling.

Even the most demanding applications and excessive multitasking are handled easily.

Graphics

The integrated graphics unit called HD Graphics 530 represents the "GT2" version of the Skylake GPU (Intel Gen. 9). The 24 Execution Units, also called EUs, are clocked at 350 - 1050 MHz and offer a performance about 20 percent above the old HD Graphics 4600. Games of 2015 can thus be played smoothly in low or medium settings. For more information about performance and features, check our page for the HD Graphics 530.

Power Consumption

Specified at a TDP of 45 W (including CPU, GPU and memory controller), the CPU is best suited for bigger notebooks 15-inches in size and above. Optionally, the TDP can be lowered to 35 watts (cTDP down), reducing both heat dissipation and performance.

Intel Core i7-6870HQ

The Intel Core i7-6870HQ is a fast quad-core processor for notebooks based on the Skylake architecture and was introduced in the beginning of 2016. Besides four CPU cores including Hyperthreading, which are clocked between 2.7-3.6 GHz (probable Turbo steps: 4 cores: up to 3.2 GHz, 2 cores: up to 3.4 GHz), the processor also includes a very fast graphics unit. The Iris Pro Graphics 580 (GT4e) has 72 EUs as well as 128 MB eDRAM cache, which can also be used by the CPU cores. It is manufactured using a 14 nm process with FinFET transistors.

Contrary to other models like the Core i7-6820HQ, the i7-6870HQ does have a much faster GPU, but neither supports the instruction set extensions TSX-NI nor vPro.

Architecture

Intel uses Skylake to replace both Broadwell as well as Haswell and therefore uses one core design for all TDP classes between 4.5-45 Watts. Several improvements of the Skylake architecture include bigger Out-to-Order-Buffer, optimizations for pre-fetching as well as bigger gains by Hyperthreading. However, the changes are small for a "Tock" – a new micro architecture – in general, so the per-MHz performance is only between 5-10 % (compared to Haswell) or less than 5 % higher (compared to Broadwell), respectively.

The i7-6870HQ also benefits from the additional eDRAM cache in some cases, which can accelerate memory-heavy applications in particular.

Performance

Thanks to the additional eDRAM cache, the i7-6870HQ should even compete with the similarly clocked i7-6820HQ and is therefore one of the fastest notebook processors in the beginning of 2016. Even the most demanding applications and excessive multi-tasking are no problem for the high-end CPU.

Graphics

The integrated GPU with the designation Iris Pro Graphics 580 (also known as "GT4e") represents the fastest version of the Skylake GPU (Intel Gen. 9). 72 Execution Units (EUs) run at 350 up to 1000 MHz and allow a performance comparable to a dedicated mainstream chip. The GPU might be able to compete with a GeForce 945M under perfect conditions and it is therefore the fastest iGPU on the market by a pretty big margin. Modern games from 2015/2016 can usually be played smoothly at medium settings. More information about the performance and the features is available on our dedicated page for the Iris Pro Graphics 580.

Power Consumption

According to its TDP of 45 Watts, the chip is primarily designed for bigger notebooks starting with 15-inch screens. The TDP can optionally be reduced to 35 Watts (cTDP down), but this would obviously affect the performance.