Fractal’s New Celsius+ S36 Prisma Liquid Cooler Review

System Installation & Testing

Test Platform:

CPU – AMD Ryzen 9 3900X
Mobo – MSI MEG X570 Godlike Gaming
RAM – 16GB (2x8GB) Silicon power XPOWER RGB 3600MHz C18
GPU – Nvidia RTX 2080 Founders Edition
SSD – Corsair MP600 2TB
PSU – Thermaltake Toughpower Grand RGB Gold 750W
Chassis – Fractal Design Meshify 2 XL

All testing is performed at default settings except for enabling XMP

Installation is ridiculously easy with Fractal’s Celsius+ S36 Prisma. Screw the fans to the radiator, and plug them into the integrated hub on the radiator. The RGB cable connects here too and daisy-chains between the fans. After this, just screw the radiator to your case, ours will be in the top.

For AMD’s AM4 socket, mounting the block is also extremely easy. Just twist the Intel bracket off, and the AMD bracket on. Hook one side over the motherboard’s mounting bracket, and use the clip and thumbscrew on the other. All that’s left is to run the 4-pin cable up and to the CPU_FAN header on your board. This is by far the easiest AiO cooler we’ve ever installed by virtue of how Fractal handles wiring with the built-in lighting and fan hub on the radiator

There are two settings for the cooler that you can select by twisting the face of the CPU block. Auto will control the fans and pump by the temperature sensed by the block, while PWM will allow your motherboard to control it like any other cooler. We’ll test both. Under power, the selected setting will glow white for a few moments before fading out.

Testing

Testing was conducted at an ambient temperature of 19C or 66F. Testing is one hour of an AIDA64 stress test, and the temperature is logged with HWiNFO.

We tested an hour with everything on auto/default. Fractal’s Celsius+ S36 provides quite acceptable results for our 3900X on auto but hovers closer to the silent end of the spectrum rather than more performance. Switching over to PWM mode and allowing the motherboard to dictate fan and pump speed directly from CPU temps shows a notable drop in temp. Forcing the PWM output to 100% drops temps a few more degrees, but it doesn’t appear the 3900X is stressing this larger cooler than much.

With all modern CPUs from both Intel and AMD automatically adjusting clock speeds based in part on cooling capability, or more specifically, temperatures, cooler temps can result in higher clock speeds. With the Cooler set to Auto, the temps are warmer, and the clock speed averages out around 3.87GHz. switching to PWM so the motherboard can control it, we see our average clock speed climb to 4.04GHz. Moving to manual 100%, clock speeds climb a hair more but not enough to write home about.

In Auto, we see the coolant is coming into the rad at about 42C, but cools down pretty quickly, dropping around 10C before it makes a U-turn at the end and comes back for a second pass.

In PWM mode, temps drop quite a lot. The coolant temp seems to be just under 30C entering the rad and drops off pretty quick. Interestingly, the motherboard VRM area is around 2C cooler as well, likely thanks to the CPU not running as warm.