Byksk Armored GPU Water Block and Backplate for ASUS ROG Astral Gaming GeForce RTX 5090 32GB (N-AS5090ASTRAL-X)

Includes CNC backplate

In this gallery — tap to open full size

N-AS5090ASTRAL-X Only 8 left in Boise, ID

$296.99USDFree 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 8 boards, and only these

This part is machined for the 8 boards listed below — nothing else. Board revisions and partner designs differ, so match your exact model against the list before you order.

ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090 32GB
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090 32GB
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090D 32GB
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090D 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090D 32GB
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090D 32GB OC

Not sure? Send us your model/part number and we'll confirm it for you.

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.

1/2in. Rigid RevolverSX Series Fitting

$7.99 ·

SecureFit SX - 3/8in ID x 5/8in OD Flexible Tubing

$8.99 ·

Male to Female G 1/4in. 90 Degree SX Rotary Elbow Fitting

$11.99 ·

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

The Bykski N-AS5090ASTRAL-X is a full-cover water block with a matching backplate for builders adding an ASUS graphics card to a custom water loop. It fits the ASUS ROG Astral Gaming GeForce RTX 5090 32GB and the other cards it fits, including the LC, OC and RTX 5090D models of the same board.

One nickel-plated copper block cools the GPU chip, memory and power stages together, and it replaces the card's fans, so the card runs cooler and quieter. Coolant passes through 56 micro-channels on the cold plate to pull heat away from the chip. The clear acrylic top and built-in 5V addressable lighting make the card a visible part of the loop.

In the box

GPU water block with backplate: 1
1.5mm thermal pads: 5
Thermal paste: 1
M2 set screws: 3
M2 x 9.5mm backplate screws: 8

If the gallery shows a parts diagram, that diagram is the source of truth for what ships.

Datasheet

Technical specifications 17 specs

Brand	Bykski
Model	N-AS5090ASTRAL-X
Cold Plate Material	Nickel-plated T2 copper
Plating Thickness	0.001 mm - 0.002 mm electroless nickel
Top Material	PMMA acrylic with armored metal plate
Backplate Material	Frosted aluminum
Block Dimensions	283.021 x 136.25 x 30.10 mm
Backplate Dimensions	283.02 x 136.25 x 22.89 mm
Cold Plate Overall Length	159.226 mm
Cold Plate Thickness	6.0 mm
Base Thickness Under Channels	0.35 mm
Micro-Channel Jet Gap	0.3 mm
Micro-Channel Count	56
Micro-Channel Surface Area	10,962.06 mm2
Port Thread	G1/4
Lighting	5V ARGB, 3-pin header
LED Strip Width	5.00 mm

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.

Confirm the hardware

This block fits 8 boards:

ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090 32GB
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090 32GB
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090D 32GB
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090D 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090D 32GB
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090D 32GB OC

Match your exact model — not the family.

Mount it dry

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

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-AS5090ASTRAL-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 8 boards:

ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090 32GB
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090 32GB
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090D 32GB
ASUS NVIDIA 5090 - ROG ASTRAL GAMING GEFORCE RTX 5090D 32GB OC
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090D 32GB
ASUS NVIDIA 5090 - ROG ASTRAL LC GAMING GEFORCE RTX 5090D 32GB OC

These are machined to a specific hardware layout, so match your exact model rather than the family before ordering. Part number N-AS5090ASTRAL-X.

Is it in stock, and when will it ship?

Yes — only 8 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 $296.99 — 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