While the company started out selling L2 cache modules for OEMs, today Corsair sells a wide variety of components and peripherals, like the Corsair 5000X case and CX750M Power Supply. Cooling has also been a staple of the company’s lineup for a long time; most recently we tested Corsair’s iCUE H100i Elite 240mm with Intel’s i9-12900K. 

But with Raptor Lake raising the bar of cooling difficulty, Corsair has sent us its strongest AIO yet – the 420mm iCUE H170i Elite LCD XT. Can it tame Intel’s 13900K and earn a spot on our best AIO coolers list? It definitely has a size advantage, as well as a high $309.99 MSRP, but we’ll have to put it through testing to find out how it performs. First, here are the specifications from Corsair.

Cooler Specifications

Packing and Included Contents 

420mm is far from small, and as such the Corsair iCUE H170i Elite LCD XT arrives in a package that’s almost as long as my arm.

Included with the package are the following:

• 420 mm Radiator
• CPU block with 2.1-inch IPS Display
• 3x 140 mm fans
• Mounts for all modern CPU sockets (including AM5 & LGA1700)
• Safety and warranty information
• Hardware lighting and PWM hub
• Pre-applied thermal paste

Installation

The installation of Corsair’s AIO is fairly simple.

1. Secure the backplate.

2. Secure the standoffs.

3. Secure the radiator and fans to the top of the case.

4. Secure the CPU block to the standoffs.

5. Secure the fan control hub, then connect the CPU block and fans to it.

Features of Corsair iCUE H170i Elite LCD XT

2.1-inch 480×480 IPS Display

On top of the CPU block is a vivid 480×480 IPS display that can show the sensor readings of your choice with a variety of display themes, or be loaded with a custom background or animated GIF of your choosing.

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Full Copper CPU plate

The CPU contact plate on Corsair’s iCUE H170i Elite LCD XT is made of copper and comes with thermal paste pre-installed.

Hardware RGB & PWM Hub

The H170i Elite comes with a hardware RGB & PWM hub, capable of supporting up to three additional extra fans, not including those that come with the cooler (6 devices supported in total).

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27mm thick 420 mm radiator

The S36 Prisma features a 420 mm radiator that’s 27 mm (1.06 inches) thick. This isn’t the thickest (or thinnest) radiator we’ve seen, but it should be compatible with any case that supports a 420mm AIO.

3x AF RGB Elite PWM 140mm fans

There’s more to a cooler than just the heatsink or radiator. The bundled fans have a significant impact on cooling and noise levels. Included with the iCUE H170i Elite LCD XT are three 140mm AF RGB Elite fans. The versions of these fans included with the cooler are slightly stronger than the standard AF RGB Elite fans, with a maximum speed of 1700RPM vs 1600 on the standard models. Corsair advertises powerful airflow, up to 89 CFM of peak airflow, a low-noise rating (10-33.8 dBA), and durability thanks to fluid dynamic bearings. Here are the fan’s specs:

Fan Curve tied to AIO Coolant temperature, rather than CPU temperature.

The pump and fan curves of the iCUE H170i Elite LCD XT are based on the temperature of the CPU coolant instead of the CPU. This has advantages and drawbacks, but many will appreciate how it reduces noise levels in common loads and eliminates bursty fan behavior. 

The disadvantage to this method is that semi-intensive, but sustained, workloads will cause the cooler to run just as loudly as it would in a fully unrestricted workload. The fans will also spin at higher speeds for a moderate period of time once the workload has completed, rather than instantly returning to low speeds. This happens because it takes a few moments to bring the AIO’s coolant temperatures down after a sustained workload.

Comprehensive Software Suite

Corsair’s iCUE software provides comprehensive customization for its coolers, components and peripherals. I was pleasantly surprised to see my motherboard’s RGB options detected by the software, allowing easy control over all system RGB functions. This is due to cooperation between the two companies that was first announced in 2020 (opens in new tab). Other motherboard brands are not currently supported by iCue.

The software allows for in-depth controls of the cooler’s LEDs. You can change the settings for each individual LED on the included AF RGB Elite fans.

You are also able to change what is shown on the CPU block’s small screen via the software. You can set it to show the time, coolant temperature, or another sensor of your choice. The background can be changed from a variety of customizable presets, or you can also upload an image or GIF file.

Testing Methodology

While it was fairly easy with previous CPU generations for coolers to keep the flagship i9 processor well under TJ max (the maximum temperature a CPU can sustain without throttling) in tough workloads, this is no longer realistically possible on current generation CPUs (and the 13900K specifically) without extreme cooling (or enabling power limits).

While in the past a CPU hitting its peak temperature was cause for concern, enthusiasts are going to have to learn to accept high temperatures as “normal” while running demanding workloads with Raptor Lake and Ryzen 7000 CPUs. Modern AMD and Intel CPUs are designed to run fairly hot without any problems – up to 95 degrees Celsius and for AMD Ryzen 7000 CPUs and up to 100 C for Intel’s Core i9-13900K. Similar behavior has been standard in laptops for years due to cooling limitations in tight spaces.

Furthermore, Intel’s Core i9-13900K supports Adaptive Boost Technology (ABT) which allows Core i9 processors to dynamically boost to higher all-core frequencies based on available thermal headroom and electrical conditions. This allows multi-core loads to operate at up to 5.5 GHz if the necessary amount of thermal dissipation is there. This feature works in a way that actively seeks high temperatures: If the chip sees that it is running underneath the 100-degree C threshold, it will increase its performance and power consumption until it reaches the safe 100 C limit, thus maintaining higher clocks (and providing better performance) for longer periods.

The increased cooling challenges posed by Raptor Lake mean that we’ve had to change some of the ways we test coolers. Some coolers were able to pass Cinebench R23 multicore testing with Intel’s 12th Gen i9-12900K when power limits were removed (although only the strongest models were able to pass that test). Most liquid coolers and all air coolers I’ve tested “failed” that test because the CPU reached TJ max in this scenario.

With Raptor Lake’s 13900K, not a single cooler tested has been able to keep the CPU under TJ max in this test – because as we pointed out, the chip is designed to dial up performance and power until it reaches that thermal result. For these intense loads, we’ll test performance by comparing the total amount of watts cooled and noise levels.

I’ll be testing Intel’s i9-13900K CPU using Asus’ TUF Gaming Z690 Gaming Plus WIFI motherboard and Cooler Master’s HAF 700 Berserker PC case, with case fans limited to 35% speeds. The motherboard’s default fan curve is used for the CPU Cooler’s fans.

In addition to testing Cinebench without power limits enforced, we’ll also be showing results when the CPU’s power consumption is limited to a more reasonable 200W. We’ll also show results at 125W for those who prefer whisper-quiet cooling, at the cost of some performance. For both of these results, we’ll show traditional delta over ambient temperature results.

We’ll provide noise level measurements recorded using a PSPL25 Sound Meter for all three power levels tested to compare how much noise each cooler makes in different scenarios. We expect most coolers to run quietly at 125W.

LGA1700 Socket Bending

Note there are many factors other than the CPU cooler that can influence your cooling performance, including the case you use and the fans installed in it. A system’s motherboard can also influence this, especially if it suffers from bending, which results in poor cooler contact with the CPU.

In order to prevent bending from impacting our cooling results, we’ve installed Thermalright’s LGA 1700 contact frame into our testing rig. If your motherboard is affected by bending, your thermal results will be worse than those shown below. Not all motherboards are affected equally by this issue. I tested Raptor Lake CPUs in two motherboards. And while one of them showed significant thermal improvements after installing Thermalright’s LGA1700 contact frame, the other motherboard showed no difference in temperatures whatsoever! Check out our review of the contact frame for more information.

Testing Configuration

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