Architecture

Under the hood of the Core i5-10400F is the 6-core "Comet Lake-S" silicon built on the same 14 nm++ process as the previous two generations. The die area is estimated to be 149.6 mm². This die looks similar to the 6-core "Coffee Lake" or "Coffee Lake Refresh" dies.


The "Comet Lake-S" silicon is laid out similar to the past four generations of Intel mainstream processors, with two rows of CPU cores flanked by the iGPU on one side and the system agent (integrated northbridge) on the other, and a Ringbus Interconnect serving as town square between the various components. The last-level cache is scattered across as slices of 1 MB or 2 MB, adding up to 12 MB of unified L3 cache all cores can access equally.

Much of the processor's uncore components are clumped into the System Agent, which contains the memory controller, PCI-Express gen 3.0 root-complex, DMI interface, and memory PHY. The iGPU solution, though present on the silicon, is permanently disabled by Intel.


The core itself is identical in design to "Skylake," and there are hence no IPC increases to be had. As we explained in the introduction, all of Intel's efforts to increase gaming, single-threaded, and less-parallelized application performance revolve around increasing clock speeds and deploying as many as three intelligent boosting algorithms to achieve the advertised clock speeds.

The Core i9-10400F has a nameplate base frequency (aka nominal clock) of 2.90 GHz, and a maximum Turbo Boost frequency of 4.30 GHz. Unlike the Core i9-10900K, it lacks Turbo Boost Max 3.0 or Thermal Velocity Boost. It still has significantly increased power limits compared to something like a Core i7-8700K, with PL1 set at 65 W and PL2 at 134 W, with a 28-second Tau (time value at which the processor is allowed to sustain elevated power levels before having to drop down to nominal clocks).

Motherboard manufacturers have been given the freedom to override PL2 and Tau as they see fit, so various motherboards implement power limits differently depending on the effectiveness of their VRM solution. You are hence rewarded for buying a pricier motherboard that has a better VRM and more aggressive vendor-supplied power-management. Of course, all boards come with Intel-spec fallbacks.

Intel introduced a handful of overclocking enhancements with the 10th generation, including the ability to toggle HyperThreading on a per-core basis rather than globally. This could be an interesting option for those gaming and streaming, where a certain number of cores have HTT disabled for the best gaming performance and certain cores have them enabled, with Windows process core affinity settings taking care of the rest.

The company also introduced the ability to overclock the DMI chipset bus. DMI is a PCIe-based interconnect that handles transfers between the processor and the chipset (PCH). The LGA1200 platform uses DMI 3.0 (comparable to PCI-Express 3.0 x4 in terms of bandwidth). Intel has apparently decoupled PCIe clock domains to enable you to overclock the DMI and PEG (that topmost x16 PCIe slot) without destabilizing your PCIe setup for graphics cards. Multiplier-based overclocking, however, isn't possible on the i5-10400F.

The Z490 Platform

Z490 is the top 400-series chipset targeted at gaming desktops and PC enthusiasts, as it enables serious overclocking and multi-GPU support. In terms of I/O capabilities, the chipset is nearly identical to the Z390, with 24 downstream PCIe gen 3.0 lanes, six SATA ports, six USB 3.2 gen 2 ports that can be converted to three USB 3.2 gen 2x2 ports, ten USB 3.2 gen 1 ports, and fourteen USB 2.0 ports. Intel is recommending its i225-V 2.5 Gbps Ethernet chip as the wired networking solution to go with Z490, and the company's AX201 802.11ax WiFi 6 WLAN solution to go with the chipset's CNVio interface.

For multiplier-locked chips like the i5-10400F, you could save a lot of money by opting for cheaper H470 or B460 chipset motherboards.