Introduction

We got our hands on the new Pentium Gold G5600 dual-core processor based on the "Coffee Lake" architecture and designed for the Intel 300-series chipset platform. There was a time when the Pentium brand denoted the very best in client computing. Since the advent of the Core brand of multi-core processors, Intel brands from the previous millennium, such as Pentium and Celeron, were relegated to the entry-level segments. The fastest Pentium couldn't match the performance of the slowest Core 2 Duo, so this product stack change made sense. AMD did something similar with its Athlon brand. Over the years, Intel's entry-level client processor lineup swelled, and stratified.

For the past decade or more, since the advent of the ULPC and Atom brand, the company maintained two distinct implementations of its x86 machine architecture—a low-power micro-architecture (e.g.: "Goldmont") and a high-power micro-architecture (e.g.: "Skylake"). This created branding chaos at the entry-level segment to where people found it difficult to tell a Pentium processor based on "Goldmont" apart from a socketed Pentium chip based on "Skylake," for example. To clear this confusion, Intel divided the Pentium brand into two, with Pentium Silver denoting a non-socketed chip based on the low-power architecture and Pentium Gold denoting socketed high-performance architecture.

Socketed Pentium chips, for the past several generations, have been dual-core and contributed to a chaos of a different kind as Intel found itself having three brands of socketed dual-core processors—Celeron, Pentium, and Core i3; features such as L3 cache amount and HyperThreading were used to differentiate the three, besides clock speeds. Then, AMD Ryzen came along and torpedoed Intel's entire mainstream desktop processor lineup, forcing a 50-100 percent core-count increase across the Core brand. With the Core i5 and Core i7 brands being six-core, Intel marked the Core i3 as quad-core. It could now make the Pentium brand a better-endowed dual-core chip (complete with HyperThreading and more L3 cache) to capture the $70-$100 market.

The Pentium Gold "Coffee Lake" series is hence the very best socketed dual-core processor Intel made to date. It's based on a new dual-core die built on the 14 nm++ silicon fabrication process, has HyperThreading (making them 2-core/4-thread), and is endowed with a healthy 4 MB of shared L3 cache (something $150-ish Core i3 SKUs used to get in previous generations). Intel also clocked the processor at 3.90 GHz, way north of the 3.20-ish GHz of previous generations. For those who don't intend to pair it with graphics cards (the vast majority of its target audience), Intel also gave it a slightly better Gen 9.5 GT2-variant iGPU, branded as UHD Graphics 630, with 24 execution units and up to 1.10 GHz clocks.



Today, we're reviewing the Pentium Gold G5600, which leads the Pentium Gold "Coffee Lake" series that also features the lower-priced G5500 and G5400. Priced just under $93, this chip is clocked at 3.90 GHz, has 4 MB of L3 cache, and features HyperThreading enabling four logical CPUs. Most desktops built with this chip won't have discrete graphics and will be used for non-gaming purposes (business desktops and mom-and-pop home PCs). We think you could also build gaming PCs with this chip, looking purely at its high clock speed and the fact that games still aren't very parallelized.

This review uses our updated test suite for processors in 2018, which includes the latest BIOS updates with microcode fixes for recent security issues, Windows 10 Fall Creators Update with all updates, and new software tests and games, which are all using the latest versions, too.

A Closer Look

The Intel Pentium Gold G5600 comes in a normal-sized box with a prominent "Gold" marking. There is a clear indicator to tell you that you need 300-series chipset motherboards to use these chips.


Intel's stock fan-heatsink for LGA115x sockets hasn't changed much in the past decade beyond evolving regulatory compliances (becoming lead-free, RoHS, etc.) It's the same top-flow cooler that has a cylindrical heatsink with radially projecting, forked aluminium ridges, which is ventilated by a 70 mm fan. With its TDP rated at 54 W, you should be able to run the G5600 with this cooler.


The Pentium Gold G5600 looks like every other LGA115x processor launched in the past decade. A point to note here is that unlike AMD, Intel is using glue and thermal paste as the interface material between the integrated heatspreader and die. Enthusiasts generally prefer soldered dies. Gamers don't care as long as their machines are quiet enough.


With this generation, the biggest point of confusion has been the package. The 8th generation Core and Pentium Gold desktop processors bear the "LGA 1151" package markings and look like they'll work on older 100-series and 200-series chipset motherboards. They'll even physically fit on them since nobody at Intel bothered to put the key notches elsewhere. The chips, however, will not work on older motherboards. The machine won't even POST. The box clearly states that you need a 300-series chipset motherboard to use the processor.

Architecture

The Pentium Gold G5600 is based on Intel's 8th generation "Coffee Lake" micro-architecture. The CPU circuit design is essentially the same as with "Skylake" but the silicon is built on Intel's third iteration of the 14 nanometer silicon fab process, which the company refers to as 14 nm++. This node improves the ability for the chipmaker to dial up clock speeds at minimal power/thermal cost. The G5600 is based on the dual-core+GT2 variant of the silicon, which has two physical CPU cores (no hidden/disabled cores), 4 MB of L3 cache across four blocks, and a Gen 9.5 GT2 graphics core with 24 execution units, commercially labeled "Intel UHD Graphics 630". The "Coffee Lake" dual-core silicon measures roughly 100 mm², physically features two CPU cores with 256 KB of dedicated L2 cache per core, and 4 MB of shared L3 cache, or 2 MB per core. The Celeron SKUs based on this silicon have 1.5 MB per core (3 MB shared L3 cache).



The system agent (integrated Northbridge) also appears to be carried over from the "Kaby Lake" die, with its dual-channel DDR4 memory interface. The processor now natively supports DDR4-2400 (JEDEC). It puts out 16 PCI-Express gen 3.0 lanes meant for PEG (PCI-Express discrete graphics). It talks to the motherboard chipset over the DMI 3.0 chipset bus with a 32 Gbps-per-direction bandwidth.



The "Coffee Lake" CPU core is of the same exact design as Skylake and Kaby Lake, which dates back to 2015. Compared to the Haswell/Broadwell core, it features an improved front-end with a 25% fatter 5 µOP pipeline, a 50% wider allocation queue depth, an improved branch-prediction unit, and a wider instruction window. The execution stage features a slightly bigger re-order buffer, a bigger integer register file, and an improved on-chip memory system. All of these contribute to a 5-10 percent IPC increase over "Haswell" to "Skylake" clock-for-clock.



Between "Skylake" and "Coffee Lake," Intel turned its R&D efforts toward refining the 14 nm process. It met with success on "Kaby Lake," and owing to its significantly higher clock speeds, "Kaby Lake" was able to provide higher performance than "Skylake." With "Coffee Lake," the nominal clock speeds look low, but Turbo Boost frequencies are higher than with "Kaby Lake," and refinements in the process allow the chip to sustain elevated boost-clock states better. As we mentioned throughout the introduction, the design focus of these chips is to increase core counts across the board in order to better compete with AMD Ryzen.

The Gen 9.5 integrated graphics core takes up nearly a third of the die area. Since it's of the same core configuration as the one on the "Kaby Lake" silicon, it still features 24 execution units in the GT2 trim (featured on the i7-8700K). Higher clocks and some driver magic let Intel brand it "UHD Graphics." Don't expect to play PUBG at 4K on this; the "UHD" moniker only indicates that the IGP can handle 4K Ultra HD displays, features modern connectivity options such as DP 1.4 and HDMI 2.0, and can playback 4K video in new formats with 10-bit color and HDR10/Dolby Vision standards.

Intel 300-series Platform

Chipset options for the Pentium Gold G5600 include the top-end Z370 Express, which the platform debuted with, followed by the H370 Express, B360 Express, and entry-level H310 Express. The Z370 Express chipset, which succeeds the Z270 Express, appears to carry over the same platform feature set. It wouldn't surprise us if the Z370 turns out to be a re-brand of the Z270; however, we have no way of telling right now. The H370 has almost all features of the Z370, but one lesser M.2 slot, lack of CPU overclocking support, and lack of multi-GPU support. The B360 Express has fewer M.2 slots still. The entry-level H310 chipset is what most people will pair this chip with. As we mentioned on the previous page, 8th generation Core processors won't work on 100-series/200-series chipset motherboards.