Introduction

We have with us for review the Intel Core i5-10400F 10th generation six-core processor. The i5-10400F joins a line of popular sub-$200 processors from Intel, such as the i5-9400 and i5-8400. They offer hardware similar to the $250 Core i5 part at lower pricing, with slightly lower clock speeds. With the 9th generation, Intel began rolling out the "F" brand extension that denotes a lack of integrated graphics, beginning with the popular $160 Core i5-9400F. The lack of iGPU lets Intel harvest silicon dies with defective graphics cores. The i5-10400F is a direct successor to this chip and is launching at $160.

The Core i5-10400F in this review is a juicy lure for gamers as it offers 6 cores, 12 threads, and 12 MB of shared L3 cache—identical to the Core i7-8700, but with lower clock speeds at less than half its price. With the advent of the 8th generation Core "Coffee Lake" triggered by AMD "Zen," game developers were finally motivated to optimize their game engines to take advantage of more than four cores. AAA titles such as "Battlefield 5", among others, are built to take advantage of six cores. The Core i5-10400F cannot simply waltz into this segment as the $180-ish AMD Ryzen 5 3600 is found to be trading blows with the much pricier i5-10600K.



The Intel Core i5-10400F is based on Intel's new "Comet Lake" microarchitecture that enables HyperThreading, increased L3 cache, and higher clock speeds across the entire 10th generation Core product stack, and debuts new boosting algorithms, although just for the Core i7 and Core i9 SKUs. Our tested Core i5-10400F ticks at the same 2.90 GHz as its predecessor, but has an increased maximum Turbo Boost frequency of 4.30 GHz, double the threads, and 50% more L3 cache. The increase in clocks is necessitated as the underlying CPU cores are of the same design as the nearly five-year-old "Skylake" microarchitecture.

The Core i5-10400F is a "locked" processor, which means you cannot overclock it using the base-clock multiplier. However, there are alternatives, such as tweaking the base clock itself. As an "F" SKU, you also lose out on the integrated graphics, particularly its awesome Quick Sync media encoder. However, if you don't care about the iGPU, you get to save around $30 over the i5-10400 that's going for around $200 these days.

In our Core i5-10400F review, we take a close look at the processor across our large selection of CPU and gaming performance benchmarks to figure out if you can potentially save yourself at least $100 by opting for this chip over the i5-10600K, or if the AMD 3600 can thwart it with its aggressive price and unlocked multiplier. We also take a look at what "overclocking" options exist on this multiplier-locked processor.

A Closer Look

Our Core i5-10400F sample came in a tray-only package. The retail packaging includes a heatsink, which will help keep overall system cost down.


The Core i5-10400F looks like any LGA1xxx processor released by Intel in the past decade. The processor is only compatible with socket LGA1200 motherboards because the position of the round notches has been changed. It will not work with an older motherboard.


Luckily, socket LGA1200 retains cooler compatibility with all older LGA115x-series sockets. This means you're going to be spoiled for choice when picking a cooler to go with this processor.

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.

Test Setup

• All applications, games, and processors are tested with the drivers and hardware listed below—no performance results were recycled between test systems.
• All games and applications are tested using the same version.
• All games are set to their highest quality setting unless indicated otherwise.