For me, water-cooling began out of necessity. I water-cooled my first PC nearly ten years ago, when, living in a house with a flat roof, my bedroom got incredibly hot in the summer months. I was already hooked on overclocking at the time and strove to save money by buying cheap, but very overclockable hardware. Unfortunately, the combination of the house's architecture and high system temperatures meant that my PC was intolerably noisy and unstable.
Infuriated, I made the move to water-cooling - not a particularly easy one as there were few guides and even fewer off-the-shelf components back then, which resulted in regular trips to the local DIY store to search for parts. I initially water-cooled my CPU, and my overheating and noise issues were solved instantly - my PC went from a hot, noisy box to a cool and quiet machine of wonder. I had more overclocking headroom than before too.
Every one of my main rigs since then has also seen me spend entire weekends building and leak-testing. In fact, the last three PCs I've built have had a water-cooled CPU and GPU, as well as the various hotspots on the motherboard too. However, a lot of today's hardware simply doesn't need water-cooling as urgently as its equivalent back in the day. People still want water-cooling, but it seems to be a desire that's separate from the need to actually cool the hardware.
Even as far back as the release Intel's first mainstream quad-core CPUs, such as the Core 2 Quad Q6600, air coolers were quickly becoming potent enough for newcomers to question the significant outlay involved with water-cooling. The new heatpipe-clad tower coolers were becoming more efficient at every step, and there's usually an air cooler that will enable you to push all but the hottest running CPUs to the max, albeit with additional noise.
However, with Intel's LGA1155 CPUs, we've seen time and time again that air coolers such as Thermaltake's Frio and BeQuiet Dark Rock Advanced are more than able to provide just as much overclocking headroom as a decent water-cooling kit, and with similar noise levels too. Our current LGA1155 thermal test kit is a case in question - we've overclocked our Core i7-2600K to a lofty 4.6GHz, and both the aforementioned coolers handled this overclock admirably.
Graphics cards are a slightly different matter, however, as we've found just as much reason to water-cool the current graphics cards such as the GeForce GTX 590 3GB as any previous generation. In fact, even mid-range graphics cards such as the GTX 560 Ti 1GB get quite warm and noisy under load, and many third party coolers haven't been able to tame them significantly.
Motherboards are a bit of mixed bag, though. I'd go as far as saying that I've had far fewer failures and stability issues since I've been water-cooling the motherboard in my PCs - the hot-running chipset on LGA1366 motherboards, for example, is almost certainly the reason for quite a few dead systems in our lab, as well as other problems I've read about in various forums.
Water-cooling your motherboard can drastically reduce the temperatures of the chipset and MOSFETs, but the water blocks are expensive
However, water-cooling your motherboard is an expensive business - full cover blocks can retail for over £100, and most LGA1155 motherboards simply don't require shedloads of voltage either. With Intel and AMD's next-generation high-end CPUs on the horizon, it will be interesting to see how future families of motherboards fare on a day to day basis - will LGA2011 be another hot-running LGA1366 for example?
Aside from noise reduction, where water-cooling still has the edge in a few key areas, there is one other reason to invest in water-cooling. It looks fantastic. There's a reason why we award points to cases that look good, and why modding projects are so popular. Lots of us want to have a cool-looking PC and are willing to spend money achieving that goal. Thankfully, the water-cooling industry has taken notice and strived to meet the demand for a diverse and flexible range of hardware.
You only have to look at websites such as Aquatuning, Chilled PC and FrozenCPU to see the huge the range of components on offer these days, which makes it very easy to make a unique water-cooled PC. In addition, the huge range of gear is appealing to those who want to go one step further than just bolting a load of off-the-shelf parts together, and instead want to either mod their PC or even build it from scratch.
Even if the next generation of hardware doesn't notably benefit from water-cooling, there's always a small gap between air cooling and extreme cooling, and there will still be a huge market for it, for the simple reason that it's cool.
What do you think the future has in store for water-cooling? Have you been put off for any reason, or do you swear by it? Let us know in the forums.