Question What is the biggest AIO CPU cooler I can buy for my new Super Tower Case? Does bigger radiator = lower CPU temperatures vs smaller radiators?


Mar 17, 2016
Hello all,

I recently bought this Super Tower PC case by Thermaltake: 900&cm_re=thermaltake_900-_-11-133-327-_-Product

I have a 9900k CPU and currently have this air cooler rated at 230W:

I never owned a AIO liquid cooler before so I need help, I am shopping around online and all I see are these AIOs with only either 1,2, or 3 fans attached to the radiator.
According to my new Thermaltake Super Tower specs, my side panel can fit a AIO with up to 5 fans but I cant find any company that sells such a AIO with 5 fans. Do 5-fan AIOs exist?

If a AIO has more fans, it means it cools the CPU better and at a lower temperature than a AIO with less fans correct? A 3-fan AIO brings a lot better temperature than a 1-fan AIO right? (And a 5-fan AIO is better than a 3-fan AIO?)

Also, if I buy a AIO, how long will it last before the liquid inside must be replaced?

Any recommendations for a BIG AIO CPU cooler for my super tower would be appreciated as well as answers to my above questions...


This is what the manufacturers spec sheet is for

Radiator Support
Left / Right Side:
1 x 480mm , 1 x 560mm

So yes, it can take large radiators.
480mm = 4x 120mm fans
560mm = 4x 140mm fans

Does larger always mean "better"? No.
A crappy 560mm setup is probably worse than a good 280mm setup.

Lower temp does not always mean "better"
The performance difference between 70C and 65C is exactly zero.

Apr 2, 2019
I believe the biggest AIO is a 360mm, which like you stated has 3 fans. The number of fans that fit is due to the rad size. Generally, the bigger the radiator the better the cooling capacity. if you want a 420 or larger or something larger than a 360 you must go with a custom loop. Keep in mind that AIO tend to have a shorter life span versus going custom loop. EK makes some decent kits that are relatively easy to install.
There's a big difference between efficiency and capacity. The more effective coolers have higher efficiency, so they'll have lower temps under high loads than less efficient designs. Capacity is somewhat different. A 120mm is roughly 140w+, 140mm/180+w, 240mm/250w+, 280mm/300w+ and the 360mm/350w+. You can generally also add upto @ 50w for the high efficiency models, so a very good 240mm can easily equal a crappy 280mm.

But that's also using the stock fans. They have a lot to do with the ability of the aio. ie: Corsair H150i Pro had great fans, the ML120mm are quiet, put out a ton of air at good speeds. The H150i Pro RGB has nice looking fans, same ML120mm (RGB version) that are just as quiet, but have half the cfm and less than half the static pressure, so efficiency drops, and the aio is better(?) looking but performance is lackluster.

You have an i9-9900k. Welcome to monster heat output, especially under higher OC values. It's best cooled by a full custom loop, which is where you get the 480/560mm coolers (4x120mm/4x140mm) from as nobody makes a stock aio above 360mm that I ever heard of.
So with AIO's, your choices are limited, best 280mm you can get, (doesn't mean most expensive) or at least a mediocre 360mm. That'll give you higher efficiency combined with high capacity.
High end popular aio review
Cross checking with other reviews will give broader results and will include a larger variety of coolers.
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