An Intel Workstation CPU Showdown: Comparing the i9-9900k to the i7-9800x

i9-9900k vs i7-9800x

Two new high-end, arguably-professional-grade Intel CPUs made their debut in late 2018: the i9-9900k and the i7-9800x, which come endowed with higher core counts, higher thread counts, and higher price tags than the previous generation of Intel CPUs.

They offer different features and are designed for compatibility with different chipsets. New Intel builders with hefty budgets and those looking to upgrade their high-end Intel workstation desktops will want to take a close look at these options.

The i9-9900k ($530)

i9-9900kThe i9-9900k is the latest addition to Intel’s 9th-generation CPUs. It boasts a 3.6 GHz base clock, 8 cores, 16 threads, and can support up to 64GB of RAM.  It offers 16 PCIe lanes, which allow you to hook up a maximum of two GPUs in SLI or Crossfire. As of January 2019, it has the distinction of being the fastest gaming CPU on the market due to its exceptional single-core speed. It also comes with integrated graphics.

The i9-9900k is compatible with B360, H310, H370, Q370, Z370, and Z390 chipset motherboards, granting it more versatility as an upgrade option (although any of those other than the Z390 will probably require a BIOS update before upgrading).

The i9-9900k outperformed the i7-9800x in every metric of the Puget Systems benchmark test. In Adobe Photoshop, the i9-9900k offered consistent speed boost in the range of 10-15% across the board.

The i7-9800x ($670)

i7-9800xThe i7-9800x offers a slightly higher base clock of 3.8 GHz, with the same 8 cores and 16 threads—but can handle 128GB of RAM. It comes with 44 PCIe slots, which is essential for anyone who plans to utilize three or more GPUs. Unlike the i9-9900k, it does not come with integrated graphics.

The i7-9800x is only compatible with X299 chipset motherboards.

The only feature advantages offered by the i7-9800x are its increased memory budget and higher number of PCIe lanes, which makes it operate like an updated i7-7820x.

Sizing up the Competition

Intel CPUs come with Turbo Boost technology, an Intel-exclusive feature designed to increase performance under load. While the i9-9900k’s base clock is slightly lower than the i7-9800x, it offers a significantly higher Turbo Boost, clocking in at 5.0 GHz compared to the to the i7’s 4.4 GHz.

As of the time of writing this article, the i9-9900k and i7-9800x average $530 and $670 on US markets respectively. This means that the faster i9-9900k is significantly cheaper than the i7-9800x.

Although (once you get past the midrange) the CPU has a minimal impact on metrics such as framerate, which is generally improved through GPU upgrades—its speed does make a difference, and impacts overall system performance. This means that gamers should consider the i9-9900k, even though the speed boost might not correlate perfectly to their framerate.

Many digital art and design programs rely on both GPU and CPU resources, such as Adobe Premiere and Photoshop, and the faster CPU has a tangible impact on workflow. Serious digital artists and video editors will benefit the most from choosing the i9-9900k over the i7-9800k as well.

r5 2400gOf course, gamers should not buy the i9-9900k expecting to use its integrated GPU for gaming. Despite being the best and latest in Intel’s line of gaming CPUs, the iGPU has remained virtually unchanged since Kaby Lake. The i9-9900k comes with UHD Graphics 630, which cannot be relied upon to play most modern games above 15 FPS on medium settings and 720p resolution, and which is easily outperformed by the iGPU that comes with AMD’s budget-tier Ryzen 5 2400g. In other words, casual gamers planning to build a mini-ITX computer without a discrete GPU—or considering a gaming laptop or drawing tablet—should look at a different line of CPUs entirely.


The average user will find the i9-9900k the more attractive option with little contest. The i9-9900k is heads and shoulders above the i7-9800x in terms of speed, and most people will find its 64GB memory budget and 16 PCIe slots more than sufficient.

The additional features of the i7-9800x are generally superfluous by comparison and, except in the most niche of circumstances, do not mitigate the lower speed and higher price. It would take a very particular and strange situation (e.g. a line of work that absolutely necessitates 128GB of RAM, or where the heavily diminishing returns of having 3 or 4 graphics cards seem worth the expense) to justify choosing the i7-9800x between these two options.