EK-FB MSI X399 RGB Monoblock Review: Full Coverage For Threadripper

Editor's Choice

Tom's Hardware Verdict

EKWB's custom liquid-cooling block for X399 motherboards and AMD's Threadripper is designed for full coverage of the die and surrounding hardware. It's a solid performer (we tested the MSI version) that comes at a price premium.


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    Excellent cooling performance

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    Exceptional build quality and materials

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    RGB lighting


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    Premium pricing

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Features & Specifications

For almost two decades, EKWB has been an iconic liquid-cooling vendor for the custom-cooling community. Widely known for offering high-quality water blocks and components, the company has grown to become a prolific one-stop vendor for providing complete cooling-loop kits, step-by-step component selection, and extreme-performance products.

The introduction of AMD’s Threadripper processors in 2017 required redesigns of all current cooling products to account for the larger surface area of these new CPUs. EK has been providing CPU-plus-motherboard monoblock products for several socket revisions, so it was only a matter of time until enthusiast TR4 socket boards would get the same treatment.

EK released early versions of its Threadripper CPU blocks, but the company found itself redesigning these parts in the midst of something of a block-performance controversy. However, the part being tested on our lab system includes the newly re-engineered block and cold plate, which was the result of EK working to make things right for its customers. (Read more on that issue here.)

The EK-FB MSI X399 Gaming RGB monoblock we are testing here is made for use with certain MSI X399 motherboards. (EK also offers versions for other makers' X399 Threadripper boards; see the full line here for Gigabyte-, ASRock-, and Asus-compatible offerings.) It comes packaged only with installation-specific items, typical for hardware designed for such a focused use. A small syringe of amusingly named "Thermal Grizzly Hydronaut" thermal paste is a welcome surprise. Installation directions step through the use of the included thermal pad, screws, and washers; you'll remove and replace the MSI stock voltage regulators’ heatsink to allow the monoblock to instead absorb heat and provide cooling.

Weighing in at 1.3 pounds, the EK-FB MSI X399 monoblock feels every bit as hefty as it looks. Using such a large amount of copper and solid acrylic proves the dedication that EK has toward using quality materials in its products.

Our Threadripper reference system uses an MSI X399 Gaming Pro Carbon AC motherboard and plays host to an AMD Threadripper 1900X processor overclocked to 4.1GHz. So naturally, this would be a perfect fit for the EK-FB MSI X399 RGB Monoblock. The full copper block is milled to exact fitment within the confines of MSI X399 boards, and nickel-plated to a lustrous, silvery finish.

The acrylic plexi top is also milled and includes a pair of liquid-cooling industry-standard G1/4 threaded connector ports. The inlet port is directly over the center of the TR4 CPU die, and the outlet is near the block’s voltage-regulator contact bar. The use of clear acrylic provides a monolithic, industrial look by providing view of the O-rings, hex screws, and milled channels below. The quad TR4 mounting bolts are embedded within the block and make use of firm spring mounts to be torqued down via the included Allen key.

A laser-cut aluminum corner trim piece, with “Threadripper” etched into it, contrasts and provides accent for the polished nickel finish.

As expected, the EK-FB MSI X399 Gaming RGB monoblock provides full coverage of the Threadripper CPU heat spreader. The nickel base and voltage-regulator contact plate also get the same plating and polish treatment. One benefit of being produced as an exact-fitment piece for specific mainboards allows mounting hardware to be engineered and milled directly into the block itself. An integrated four-pin RGB cable extends from under the laser-cut Threadripper logo plate and is compatible with standard four-pin RGB motherboards or third-party controllers.

With the EK-FB MSI X399 RGB monoblock installed on our MSI X399 Gaming Pro Carbon AC motherboard, the block dominates the PCB landscape while allowing access to all DIMM slots and nearby motherboard headers. The finish and design of the block are right at home with the silver-and-black color scheme of the MSI board.

With built-in RGB LED lighting, the EK-FB MSI X399 Gaming RGB monoblock is compatible with standard four-pin RGB lighting controls, including those on our MSI X399 Gaming Pro Carbon AC motherboard. Under low-light conditions, the LEDs produce impressive luminance and glow directly around the center of the block's inlet port.


Swipe to scroll horizontally
MaterialsCopper, nickel, acrylic
Block Width3.89" / 86.1mm (4.48" / 113.9mm voltage-regulator contact)
Block Length5.63" / 142.9mm
Block Height0.8" / 20.2mm (1.1" / 27.6mm voltage-regulator contact)
AMD SocketsTR4, SP3
Intel Sockets
ConnectorsFour-pin RGB
Weight21.4 oz. / 606g
PortsG1/4 (x2)
WarrantyTwo years

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Garrett Carver
CPU Cooling Reviewer

Garrett Carver is a contributor for Tom’s Hardware, primarily covering thermal compound comparisons and CPU cooling reviews; both air and liquid, including multiple variations of each.