Bykski Armored End Port GPU Waterblock with Backplate for ASUS ROG Astral GeForce RTX 5090 32GB OC Edition (N-AS5090ASTRAL-X)

Includes CNC backplate

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Bykski Armored End Port GPU Waterblock with Backplate for ASUS ROG Astral GeForce RTX 5090 32GB OC Edition (N-AS5090ASTRAL-X)

5.0 (1) 5.0 out of 5 stars, 1 review Read the reviews

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.

What this works with

Check these against your build before you order. If anything here does not match what you have, ask us first — it is cheaper than a return.

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

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

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.

Exclusive US distributor

The official US source for Bykski, so every part is genuine.

Before you install it

This is a component, not an assembly — how it goes in depends on the loop it is joining. What does not change is the last step: 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.

About this part

The Bykski N-AS5090ASTRAL-X water block and aluminum backplate cool ASUS ROG Astral GeForce RTX 5090 cards. A CNC-machined T2 copper base cools the GPU chip, while thermal pads transfer heat from the memory and power stages.

Coolant flows through 56 micro-channels with 0.3 mm jet spacing across 10,962.06 mm² of surface area to lower operating temperatures and remove fan noise. The clear acrylic top displays fluid flow through the cooling 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 fitted it, say which board.

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?

This part is specified by what it connects to, not by a card model:

ONLY Compatible with:

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

Check those against your build before you order. If anything does not match, ask us first — it is cheaper than a return. 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?

BYKSKI.US, the exclusive US distributor, from Boise, Idaho. Claims are handled domestically 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?

Check the parts list above against what you already have. If you are building a loop from scratch, send us the full parts list and we will tell you what is missing before you order.

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