Intel Core i7-8700 vs Intel Core i7-6650U vs Intel Core i5-8600K

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 i7-6650U

The Intel Core i7-6650U is an ULV (ultra low voltage) dual-core SoC based on the Skylake architecture. In September 2015, it's the fastest CPU of the 15 W series (besides the i7-6600U) and can be found in ultrabooks as well as normal notebooks. In addition to two CPU cores with Hyper-Threading clocked at 2.2 - 3.4 GHz (2 cores: max. 3.2 GHz), the chip also integrates an Iris Graphics 540 GPU with 64 MB of dedicated eDRAM memory and a dual-channel DDR4-2133/DDR3L-1600 memory controller. The SoC is manufactured using a 14 nm process with FinFET transistors.

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").

Furthermore, the organisation of the eDRAM cache has been modified. Instead of acting like a victim cache, which has to be adressed via the L3/LLC, the eDRAM can now be adressed directly by programms just like the main memory. The size is still 128 MB for the quad-core models (4C + GT4e), while the dual-core chips (2C + GT3e) only offer 64 MB.

Performance

According to the specified clock rates and the improved architecture, the Core i7-6650U should perform similar to a Core i5-4310M (Haswell, 37 W) and is one of the fastest ULV dual-cores as of late 2015. Thus, the CPU has sufficient power for office and multimedia purposes as well as more demanding applications and multitasking.

Graphics

The integrated graphics unit called Iris Graphics 540 represents the "GT3e" version of the Skylake GPU (Intel Gen. 9). The 48 Execution Units, also called EUs, are clocked at 300 - 1050 MHz and offer (thanks to the fast eDRAM cache) a performance sligthly above a dedicated GeForce 920M. 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 Iris Graphics 540.

Power Consumption

Specified at a TDP of 15 W (including CPU, GPU and memory controller), the CPU is best suited for small notebooks and ultrabooks (11-inches and above). Optionally, the TDP can be lowered to 9.5 watts (cTDP down), reducing both heat dissipation and performance and allowing even more compact designs.

Intel Core i5-8600K

The Intel Core i5-8600K 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 3.6 and 4.3 GHz and can execute up to six threads simultaneously (no HyperThreading). According to Intel, the CPU is manufactured in an improved 14nm (14nm++) process. The i5-8600K is comparatively easy to overclock thanks to the unlocked multiplier.

Performance

Due to the two additional cores, performance has increased significantly compared to the Core i7-7700K when all cores are in use. Single-core performance has not improved since its Kaby Lake predecessor. As a high-end model, the i5-8600K is suitable for the most demanding applications and games.

Graphics

The integrated Intel UHD Graphics 630 iGPU is basically identical to the previous generation Intel HD Graphics 630. Only some low demanding games are playable with this graphics card (see GPU page linked above).

Power Consumption

Intel specifies the TDP with 95 watts. Therefore, well-dimensioned cooling systems should easily manage to deal with the created heat. We expect increased efficiency due to the higher performance.