Alphacool ST30 X-Flow 360mm Radiator Review

Welcome to another Extreme Rigs radiator review. Today our attention is on the NexXxos ST30 X-Flow 360mm which is another model from Alphacool’s ever expanding and extremely popular range of water cooling radiators.

In this ST30 X-Flow review we’ll share the results of our thermal performance and restriction testing. We’ll also take a look at it’s construction, analyze the performance data and compare some of it’s results against the regular ST30 360.

Firstly a big thanks to Aqua Tuning for providing the Alphacool ST30 X-Flow review sample. The ongoing support offered by Aqua Tuning is greatly appreciated by Extreme Rigs and ultimately means you the reader can make more informed purchase decisions.

What’s in the Box?

The ST30 X-Flow sample arrived in full retail packaging consistent with the Alphacool NexXxos range.
Flipping the lid on the box we see the familiar internal packaging layout.

The radiator is enclosed in a bubble wrap bag and at one end is a small cardboard box which contains the included accessories. Small foam pieces have also been placed at each end to prevent movement during shipping.

Alphacool usually package their products extremely well and the ST30 X-Flow is no exception. Every effort has been made to ensure the product arrives to the purchaser in tip top shape.


Extent of Delivery: (as listed by Alphacool)

1x Radiator
2x screw plug
Mounting Material

Inside the accessory box pictured above are 8 x zip lock bags:

3 x bags: M3 x 30mm (12 screws)
3 x bags: M3 x 35mm (12 screws)
1 x bag: M3 x 6mm (12 screws)
1 x bag: 2 x Stop Plugs and 1 x Allen Key

Only the last ~4mm on both 30mm and 35mm screw sets have been threaded before a short taper into a thicker shank. We certainly like this process because it is a fail safe for radiator punctures often caused from wrong length screws being used.

The screws in the short set measure ~6mm in length are ideal for attaching reservoir/pump brackets onto the radiator OR to mount the radiator directly to a chassis panel or radiator mounting bracket. There is a caveat with the second option though, the panel/bracket must have a cutout for the stop plug or fitting at each end.

All the screws are deep black and feature hex head drive slots and wide heads. M3 is not our preferred thread, but apart from that, the provided screw sets are as good as one could hope for and the included “bonus” Allen Key for installation/removal is a welcome inclusion.

The 2 x stop plugs provided are brass with a black nickel finish.
ST30-360-X-Flow-206While certainly functional and the aesthetics may appeal to some users, we can’t help thinking that all black stop plugs such as those provided with the Eisdecke D5 Pump Top would be a better inclusion.
Onwards to technical specifications!


    • Alphacool also have x-flow versions of their other radiators such as the XT45 and UT60. If you want thickest I think the UT60 is the only choice out there 🙂

    • In general the Black Ice Nemesis GTS generally seems to perform the best out of any slim radiators though the tradeoff is that it’s very high restriction.

      • Does that cancel out their overall performance though (which seems excellent)? I would have thought for the vast majority loops the Nemesis GTS would still be the best choice when seeking a low RPM rad solution?