Conclusion

Like the EK Supreme HF Full-Nickel we just tested, we really like the AquaComputer kryos HF for its performance.  It doesn’t stand out with clearcut supremacy, however. With premium TIM, it falls behind the Supreme HF Full-Ni; with subpar TIM it falls behind the CPU-370; with MX-2 class TIM it does eke out a victory over the Supreme HF and CPU-370.  But to get the victories, it needs to be altered from its stock form.  Overall, no single block is the hands-down best performer and that seems to be the state of the CPU block market right now. That leaves the rest of the block and kit to impress and differentiate.  Because everyone has a different take and a different valuation of how much looks mean (and what looks good), it really comes down to usability, price, mounting, and the slight separations in performance.

First, the good.  The AquaComputer cuplex kryos HF is easily the best performer to-date with Stock TIM.  It does this by including PK-1, which is a phenomenal TIM. With the thick o-ring installed, it’s also the best performer with MX-2.  The mounting system produces high mounting pressure that’s even at all four corners, minimizing the performance impact of TIM (TIM only hurts performance, the best TIMs are the ones that degrade performance the least…like with the CPU-370, the kryos HF does a good job of mitigating TIM performance deficiencies).  Fitting compatibility is a lot better than it was with the original kryos blocks.

But not everything is rosy.  While the thermal performance is great, the restriction is medium-high and the decrease in flowrate it causes may impact the performance of other blocks in your loop.  Overall, I’d say the restriction is acceptable and appropriate, but it’s not low enough to be of no concern.

Once you step away from the restriction, the thermal performance, and the mounting system performance and look at block and mounting system usability, things can get pretty bleak.  The mounting system, in use, is even worse than the original EK mounting system.  Initial installation is more difficult and so is repeated use. The one redeeming quality it has is that it has stops for the thumbscrews, meaning even pressure.  Those stops kick in at extremely high mounting pressure, resulting in good mounting system performance, making the mounting system impressive in the graphs but in actual use the mounting system is just unpleasant. Like we said in the Supreme HF Full-Ni review, we maintain that assembly shouldn’t be required and small, losable parts (like washers) shouldn’t be required anywhere. Additionally, mounting a block should be straightforward and really easy. The kryos HF doesn’t meet any of those criteria.

With block usability, the kryos HF isn’t that impressive, either.  The fitting compatibility, while improved over the original kryos XT, isn’t great.  Socket compatibility is lacking–only Intel or AMD is included with the block, not both.  The mounting brackets don’t rest in their final position, making bracket swaps (or any block-opening task) a chore.  The best configuration isn’t the stock configuration, either, which I don’t understand.  Why include a component (in this case, the thick o-ring) that improves performance but not make it a stock component?  If there’s good reason to not make it stock (permanent deformation of the base?), maybe it shouldn’t be included at all.   From my perspective, the stock o-ring only has one use: improved compatibility with Indigo Xtreme (IX can be difficult to reflow with bowed blocks)…but that’s a corner case.

It’s not that I don’t like this block: I like it a a lot, but it’s my responsibility to be critical.  Not all blocks are equal in performance and not all blocks are equal in usability, I try to point out the differences everywhere I can.  As for improvements that I’d like to see, I’d like to see some significant mounting system usability improvements, I’d like to see the thick o-ring installed as stock, and I’d like to have seen more clarity on the revisions out there (it seems every block in the kryos line has been revised for the HF barb spacing, but when the change happened there was no way to differentiate from new vs. old).

So if you’re looking to buy the AquaComputer kryos HF, what do you get?  Why should you buy it?  Why shouldn’t you buy it?  You get a block that is a great performer with all TIMs and at all pumping powers.  It comes with great TIM, so great there’s almost no reason to buy any other TIM.  It comes in four trims ranging in looks, price, and mounting system, all with similar performance: Delrin (black, plastic variety at just $50, but with an even more primitive mounting system), Pro (plain brass, no backplate), HF (plain copper, full mounting system), and the XT (nickel plated brass, full mounting system).

However, as good as the performance is, it’s hard to outright recommend this block. Its barb compatibility is only decent. At just under $100, the price can be a deal breaker. The usability isn’t quite a deal breaker, but assembling the block to swap o-rings (which you should) or to switch mounting plates (definitely should if you have the wrong ones) is cumbersome and annoying.  And then to top it off, the mounting system is a deal breaker. Initial assembly is the worst of any block I’ve tested so far, as is repeated use (but the mounting system does, eventually, get the job done well).  Like with the Supreme HF Full-Ni, its issues largely concern things that can’t be summed up in a chart, which is why they’re repeated multiple times throughout the review.

In all, the AquaComputer kryos HF is a combination of great performance, a pretty poor mounting system, and a couple noteworthy usability and configuration issues. In order for someone to pick a kryos HF, they should do it based on looks or its overall great performance.

A big thanks goes out to Enerdyne for the Indigo Xtreme ETIs used in this review and to XtremeSystems.org member “theseeker” for providing the kryos HF.