Bykski Metal/POM GPU Water Block and Backplate For NVIDIA Geforce RTX 4090 Public Version (N-RTX4090-X)

Bykski Metal/POM GPU Water Block and Backplate For NVIDIA Geforce RTX 4090 Public Version (N-RTX4090-X)
Includes CNC backplate
In this gallery — tap to open full size
N-RTX4090-X Only 3 left in Boise, ID
$263.99USDFree shipping, lower 48

US import duties and tariffs are included in every price.

Ships the same business day on orders placed before 2:00 PM MST. Overnight delivery available at checkout.
Ships directly from our Idaho inventory. You avoid overseas sellers, processing delays, international shipping, customs hold-ups and additional fees.
Fits these 3 boards, and only these

This part is machined for the 3 boards listed below — nothing else. Board revisions and partner designs differ, so match your exact model against the list before you order.

  • NVIDIA NVIDIA 4090 - GEFORCE RTX 4090 PUBLIC VERSION
  • NVIDIA NVIDIA 4090 - GEFORCE RTX 4090 24GD6X TURBINE
  • LEADTEK NVIDIA 4090 - GEFORCE RTX 4090
Not sure? Send us your model/part number and we'll confirm it for you.
or ready to checkout now
Fittings for this block

PrimoChill SX fittings for the G1/4 ports, in stock in Boise. Pick a finish and how many you need; 6+ in any mix and the price drops.

Pick a finish, then add quantities.
Building your first loop? Plan the rest of it
Why buy it here
US warranty, handled in Boise
Claims are settled here, by the people who sold it to you.
Custom watercooling since 2002
PrimoChill, from Boise, Idaho.

About this part

Designed for the NVIDIA Geforce RTX 4090 Public Version graphics card requiring 24x7 hours of work to build all-metal construction, safety, and durability. The design of the stainless steel panel makes it possible for the video card water cooler head to be ultra-thin. 

The block is constructed of high-purity copper that is electroplated to prevent oxidation. A high-flow design is used to allow multiple blocks to run in series. 

In the box
  • 1x Full Coverage GPU Water Block
  • 1x Backplate
  • 1x Mounting Hardware
  • Thermal grease
If the gallery shows a parts diagram, that diagram is the source of truth for what ships.
Datasheet
Block MaterialNickel Electroplated High Purity Copper / Stainless Steel / POM
Backplate MaterialBlack Anodized Aluminum (not in contact with coolant)
SKUN-RTX4090-X

What buyers said

Left by people who bought this part here. Compatibility reports are the useful ones — if you installed it, say which board.

What installing it actually involves

Three steps, in the order that matters. The one people get wrong is the first.

01
Confirm the hardware

This block fits 3 boards:

  • NVIDIA NVIDIA 4090 - GEFORCE RTX 4090 PUBLIC VERSION
  • NVIDIA NVIDIA 4090 - GEFORCE RTX 4090 24GD6X TURBINE
  • LEADTEK NVIDIA 4090 - GEFORCE RTX 4090

Match your exact model — not the family.

02
Mount it dry

Thermal interface material as supplied. Even mounting pressure, correct bracket orientation, no over-torquing.

03
Leak test before power

Run the pump on a bench supply with the rest of the system unpowered. 24 hours is the standard, an hour is the minimum.

Custom water cooling is installed by you, at your own risk. We are not responsible for leaks, or for damage to your parts or system. If you're unsure at any step, ask before you power the loop.

Questions people ask about this part

Answers specific to N-RTX4090-X. If yours isn't here, ask — we'd rather talk you out of the wrong part than sell you one.

What does this part fit?

It is machined for 3 boards:

  • NVIDIA NVIDIA 4090 - GEFORCE RTX 4090 PUBLIC VERSION
  • NVIDIA NVIDIA 4090 - GEFORCE RTX 4090 24GD6X TURBINE
  • LEADTEK NVIDIA 4090 - GEFORCE RTX 4090

These are machined to a specific hardware layout, so match your exact model rather than the family before ordering. Part number N-RTX4090-X.

Is it in stock, and when will it ship?
Yes — only 3 left in Boise, Idaho. Orders placed before 2:00 PM MST on a business day ship the same day — we do not ship weekends or US holidays. Overnight delivery is available at checkout.
Can I return it if it turns out not to fit?
Yes. Returns are accepted within 30 days and are easy to start in the support center. Unopened items can be returned for store credit with no restocking fee; other returns carry a restocking fee, higher for items that have been installed or used. So we would rather check the fit with you first: send us the model and we will check it against this part.
Will I pay import duties or customs charges on delivery?
Not on a US order. US import duties and tariffs are already included in the price, so nothing is collected at the door and there is no brokerage fee. Orders shipped outside the US may owe that country's customs fees and duties.
Who handles the warranty?
PrimoChill, from Boise, Idaho. Every claim is handled directly by our support team rather than returned to an overseas factory. Installation is at your own risk: we are not responsible for leaks or damage to other hardware.
Is shipping free?
Yes — shipping is included at this price for addresses in the lower 48 US states.
Are printed instructions included?
No printed manual is included. Installation references are in the product gallery images, and the install guides on this site cover the process step by step.
Do I need anything else to use it?
A water block is one component of a loop: you also need a pump, a radiator, fittings, tubing and coolant. If you are starting from nothing, an AIO or a distro-plate kit is the shorter route — ask and we will spec it.

Ask us before you order

Send your exact hardware model and we'll confirm the right part before you spend $263.99 — or tell you honestly that this isn't the one.

Returns are accepted within 30 days and are easy to start in the support center. Unopened items can be returned for store credit with no restocking fee; other returns carry a restocking fee, higher for items that have been installed or used.

Ask about compatibility