And liquid coolers get better with size. Like some huge air coolers, not every case has the fittings to even route an external radiator and at that point you're also increasing in cost, a lot more. In the end liquid coolers and air coolers end with the same process. Dissipating the heat through a gigantic chunk of metal. The difference is where it resides and the method of transferring it. Liquid goes with well, a liquid, of course, and air goes through heat pipes. A larger radiator the better the cooling as the liquid has more surface area to dissipate the heat and in turn the fan has more surface area to cool down said radiator. Increasing in pipe diameter is also a consideration for increasing performance.