The Watercool Heatkiller 3.0 LT is regarded as the king of the mountain right now. And for good reason, it’s a low restriction block that has tremendous popularity due to its thermal performance. Though the Heatkillers have long used channel based cooling (akin to the Supremes and Whitewater and others), the newest flagships, 3.0 LT and Cu, take it to a whole new level. There’s more channels than ever providing more low-restriction surface area within just 2mm of the IHS than ever. It’s less complicated than it sounds really–the base is 2mm thick and over the width of a typical IHS, it has ~52 microchannels that are 1.5mm deep into the base. What does that mean for you? You have water flowing within .5mm of the very bottom of the base and have a lot of surface area really, really close to the heatsource, your CPU. In addition to that, you also have an impingement plate meant to distribute flow evenly through the channels. It’s a winning combination. It should be no surprise that the Heatkiller 3.0 LT provides the best as-tested performance of any block I’ve tested so far (though the review is of course worth a read–I show you how to get an even better performance below!).
The Watercool Heatkiller 3.0 LC is the low cost sibling of the LT/Cu. Coming in some twenty dollars less expensive, it’s an interesting block. It provides all the features of the LT/Cu, but does it with less intricacy and flair. There’s no metal accent piece at the nozzles, a minor aesthetic difference–but there’s also more important differences to performance. The number of microchannels is down roughly 1/3rd (reducing surface area by roughly 25%) and the impingement plate is down. What results is an even lower restriction block with the same fundamental performance as the LT/Cu, but just a tick or two hotter and tick or two less expensive.
This test will focus on the performance of the blocks in general and over a large flowrate spectrum. Results from the installments of Roundup #2 will be compiled, as they’re posted, into an Overall Comparison page.
My waterblock testing methodology has evolved over the past few months and I think it’s finally at a resting point where I can start piling up test results rather than tweak the methodology (and thus preventing cross-comparisons). I use Dallas One Wire DS18B20 temperature probes at various points through my watercooling loop and at the air intake to measure temperatures, I’ve isolated the radiators so that the flowrate through them never changes, I use six different pump settings for each block, and use good testing practice by performing 5 mounts. Where applicable, I will also test various modifications to the blocks. These include testing various orientations and removing/adding various midplates, nozzles, dividers, etc. In some cases I will also modify the mounting system and present results from increased mounting pressure. For my waterblock tests, I’ll perform 5 mounts of each configuration for every waterblock. The best configuration will then go on to be tested through the full flowrate spectrum.