https://www.techpowerup.com/234497/i...by-lake-x-sell

Intel announced retail availability of its new Core X-series HEDT (high-end desktop) processors in the LGA2066 package, designed for motherboards based on the Intel X299 Express chipset. These include the 4-core/4-thread Core i5-7640X and 4-core/8-thread Core i7-7740X based on the "Kaby Lake-X" silicon; and 6-core/12-thread Core i7-7800X, 8-core/16-thread Core i7-7820X, and 10-core/20-thread Core i9-7900X chips based on the "Skylake-X" silicon. Compatible socket LGA2066 motherboards based on the X299 chipset began selling, too.

The Core i5-7640X features 4.00 GHz clocks with 4.20 GHz Turbo Boost, and 6 MB of L3 cache. The i7-7740X tops that with 4.30 GHz core and 4.50 GHz Turbo Boost out of the box, 8 MB of L3 cache, and HyperThreading. Both these chips feature just dual-channel DDR4 memory controller, meaning that you'll be able to use just four out of eight DIMM slots in most LGA2066 motherboards. The i5-7640X is priced at USD $242, while the i7-7740X goes for $339. These are the same prices at which you can buy the LGA1151 Core i5-7600K and i7-7700K, respectively, so an attempt is being made to transition all PC enthusiasts over to the HEDT platform.
The Core i7-7800X 6-core/12-thread chip ships with clock speeds of 3.50 GHz, and 4.00 GHz Turbo Boost; and 8.25 MB of L3 cache. You get a full quad-channel DDR4 memory controller; but like the "Kaby Lake-X" chips, this chip too has a limited PCI-Express budget of 28 lanes, so you can't run two graphics cards at full x16 bandwidth (wasn't that the whole point of the HEDT platform?). The i7-7800X is priced at $389, just $50 more than the i7-7740X, which seems like a bargain for the two extra cores and a whopping 0.25 MB of more L3 cache.

The Core i7-7820X 8-core/16-thread part is clocked at 3.60 GHz with 4.30 GHz Turbo Boost; featuring 11 MB of L3 cache, a quad-channel DDR4 memory controller; yet the same limited 28-lane PCIe root complex. It is priced at $599. Back in my day, a $279 Core i7-920 paired with any X58 motherboard to give you full x16 lanes to two graphics cards, and enabled 3-way and 4-way multi-GPU configurations. If that's what you want, then get ready to pay top-dollar for the Core i9-7900X.

The Core i9-7900X at $999 is your price of admission for the 44-lane PCIe root complex of the "Skylake-X" silicon. This 10-core/20-thread processor is clocked at 3.30 GHz, with 4.30 GHz Turbo Boost, and 13.75 MB of L3 cache. Both the i9-7900X and i7-7820X feature Intel's new Turbo Boost Max 3.0 feature, which adds a further 200 MHz to the max Turbo Boost frequency, if your cooling is satisfactory. All chips being launched today feature unlocked base-clock multipliers, which make overclocking a breeze. All "Skylake-X" chips feature TDP ratings of 140W.