World's smallest RTX 4090 card: Alphacool's latest waterblock transforms the Nvidia beast into a compact 1-slot GPU

The rate at which Nvidia’s GPU coolers are bulking up with every new generation these days is subject for vehement critics as well as wild internet memes. The top-tier GeForce cards have gone from 1 slot die-sized coolers in the early days to massive 3-slot coolers the size of a brick for the latest models, and we are wondering if these can get any bigger in a few years. This is particularly frustrating for DIY builders who find it increasingly difficult to fit such monsters in ITX builds, but there is still hope. Alphacool’s latest waterblock can tame the beasts and turn them into 1-slot neat-looking cards that can fit a large variety of form-factors without sacrificing any performance, and at the same time keeping the cards at sub-60° C.

Now, there is a small caveat here, as the Alphacool enterprise-level waterblock only fits a particular PCB size found on INNO3D’s RTX 4090 cards. The silver lining is that these cards are some of the most affordable versions on the market. The replacement of the air-based cooler is quite easy, and the waterblock also comes with its own thermal pads for the front and back plates.

YouTuber Optimum Tech demonstrates this process in his latest video where he shows how the waterblock essentially cuts down the length by almost 50%, in addition to making it an ultra-compact 1-slot card. With the water coolant fittings at the right end, the waterblock is only 210 mm in length and 150 mm in width.

Optimum Tech tested the Alphacool waterblock with a 280 mm radiator and the temperatures go up to 57° C during a Furmark session, but in gaming scenarios the temperatures would drop to 53-54° C. Granted, the tests are performed on an open-air setup, so a dual-radiator would work better inside an ITX case.

The Alphacool ES GeForce RTX 4090 reference design waterblock with backplate is available at retailers like Aquatuning for US$166 excluding shipping.

Buy the INNO3D GeForce RTX 4090 iChill X3 GPU on Amazon