Details
Thermal Grizzly's DeltaMate GPU Block - ROG Astral RTX 5090 is a full-cover GPU water block for ASUS ROG Astral GeForce RTX 5090 graphics cards, here with the tempered acrylic (PMMA) viewing window. Prefer glass? The Glass Edition is here.
Properties
- Fits
- ASUS ROG Astral and Astral LC GeForce RTX 5090
- Cold plates
- Nickel-plated copper, 86 microfins at 0.2 mm
- Window
- Tempered PMMA (acrylic), 27 addressable RGB LEDs
- Ports
- 2x G1/4-inch, 28 mm apart
- Size
- 28.2 x 13.5 x 2.8 cm, 1.5 slots
- Weight
- 2142 g, 3600 g boxed
Massive copper cooler with dual cold plate design
The block features a massive copper cooler composed of two coldplates secured together with screws, and the coolant flow across it is what Thermal Grizzly credits for the cooling performance. The smaller core coldplate makes direct contact with the GPU die. It is a modular Ultra High-Performance Coldplate, milled separately, with a slot width of 0.2 mm, a fin width of 0.2 mm and a fin height of 2.5 mm. That results in a nickel-plated copper surface area of 21,009 mm² on the core coldplate alone.
The larger VRM/VRAM coldplate is designed for cooling the video memory (VRAM) and the voltage regulation modules (VRM), giving targeted cooling for all VRAM and VRM components. It weighs over 1,100 grams and is also made of nickel-plated copper. After glass bead blasting, the contact surfaces for the GPU, VRAM and VRM are finely CNC-machined to ensure optimal thermal transfer. Both plates are CNC-machined rather than made by the skiving process. Skiving can produce a similar microfin structure, but according to Thermal Grizzly it deforms the material as the fins are raised, which can reduce cooling performance.
Durability and design
This is a full metal construction: a black anodized aluminum housing (6082 alloy) and backplate around the cold plates, sealed with EPDM O-rings, with an RGB-illuminated viewing window on top. Integrated into the housing is a strip of 27 addressable RGB LEDs that illuminate the tempered acrylic. These LEDs plug into the motherboard and are controlled via its 3-pin ARGB header (+5V/DATA/GND). Once the milling process is done, the acrylic glass undergoes an annealing process to relieve internal stresses. Thermal Grizzly says this ensures that no stress cracks form over time, as can occur with tempered acrylic during prolonged use.
Terminal and fittings
The block comes pre-equipped with the DeltaMate GPU Block - Direct Terminal, made of solid nickel-plated brass and featuring one inlet and one outlet, each with G1/4-inch threading. In a standard ATX case both ports face the front of the case. Brass is an alloy of copper and zinc. It offers the advantage of being anodically compatible with other metals while being both harder and more corrosion-resistant than pure copper. Both ports must be used, so the block takes two compression fittings, such as the DeltaMate 16/10.
The block is configurable with either direct (2-port) or pass-through (4-port) brass fittings. The 4-port option is the separate Through Terminal, which adds inlet and outlet ports on the top and bottom for more ways to route the tubes.
"The Oracle"
The GPU water block is shipped mounted to a spacer PCB, also referred to as a "dummy" PCB and known as "The Oracle". It matches the exact dimensions of the original ASUS ROG Astral RTX 5090 PCB. This allows the block to be used directly out of the box for planning a custom liquid cooling loop. It enables users to check alignment and fitment before any disassembly, significantly simplifying the installation process. The PCB also serves as a template for the mounting process, showing the positions of screws and thermal pads at 1:1 scale. After installation of the water block it can be used to reinstall the original air cooler for safe storage.
Compatible graphics cards
Thermal Grizzly has verified the block on the cards below and says any card not listed should be considered incompatible.
- ROG Astral GeForce RTX 5090 32GB GDDR7 OC Edition
- ROG Astral GeForce RTX 5090 32GB GDDR7
- ROG Astral LC GeForce RTX 5090 32GB GDDR7 OC Edition
- ROG Astral LC GeForce RTX 5090 32GB GDDR7
- ROG Astral GeForce RTX 5090 32GB GDDR7 WHITE OC Edition
- ROG Astral GeForce RTX 5090 32GB GDDR7 WHITE Edition
Important notes on fitting it
This product requires assembly and is recommended for use and installation by experienced users only. Upgrading a graphics card to a custom water cooler may void the card manufacturer's warranty. The box includes Thermal Grizzly thermal paste and pads for the whole job. The pads are packed by thickness and must be cut to size, with the protective foil removed from both sides before they go on. TG Putty Advance may be used on the VRAM in place of pads, and the Duronaut paste goes on the GPU die in a thin, even layer. The block holds 76 ml of coolant.
General notes on water-cooling products
- Do not use the block in combination with water cooling components made of aluminum that come into contact with coolant, such as radiators with aluminum tubing.
- We recommend using suitable coolants: ones that contain biocides and corrosion inhibitors and are free of particles that could restrict flow or clog the loop.
- Before filling, the system should be tested for leaks using an air pressure tester (maximum 0.5 bar) for at least one hour. We stock a leak tester here.
- After filling, the loop should be regularly inspected during the first 24 hours for any signs of coolant leakage.
- According to Thermal Grizzly's specification, the operating pressure must not exceed 0.6 bar.
In the box
- DeltaMate GPU Block - ROG Astral RTX 5090 Black
- HexThinHead M2.5 x 4mm screws, black
- HexThinHead M2.5 x 6mm screws, black
- DIN934 M2.5 nuts, black
- M2.5 polyamide washers
- Pair of latex gloves
- Allen keys: 1.5 mm, 2 mm, 2.5 mm and 8 mm
- TG Spatula and TG Spatula Pro
- TG Putty Advance, 30g
- TG Duronaut, 6g
- TG Minus Pads Advance in 1.0 mm, 1.5 mm and 2.0 mm
- TG Minus Pad High Compression in 3.0 mm and 4.0 mm
Thermal Grizzly's manual, data sheet and compatibility list are PDFs, and a 3D model (STEP) is on its product page.
