Conclusion: Liquid Metal vs. Thermal Paste on Delidded CPUs
We want to make clear – primarily for Intel – that this isn’t just looking at CPU thermal performance from the perspective of overclocking. Yes, a higher frequency can be had more easily by driving down temperatures, but that’s not the core of this. Intel has a few classes of users with these HEDT CPUs, one of which includes professional workstation users, another includes enthusiasts, and then some smaller grouping of “I want the best and have lots of money” users.
For almost all of these, perhaps excluding overclocking enthusiasts, noise is a concern. Cost of the cooling solution is a concern. The near-necessity to purchase high-end 240 & 280mm coolers and run them at max or near-max fan speeds means that there is a hidden cost to these CPUs, and it’s in the cooler. Overclocking starts demanding exotic solutions, custom loops, or 360-420mm radiators with high-end fans. Prices are high on all of these components and noise is high, and yet, not one of these solutions is remotely as efficient at improving thermal performance as a $5 liquid metal application. We are not asking Intel to use liquid metal, but we’d ask that the company considers something between the current Dow Corning TIM and our liquid metal stand-in as “anything better.” Solder has been done in the past, but it may be out of the cards depending on the real reason for sticking to TIM – this could be a matter of grants and environmental impact, it could be engineering challenges (that somehow exist now and not previously, granted), it could be cost, or it could be something else altogether. We don’t know.
What we do know is that, just from the above testing, Intel isn’t doing the best it can, and the company is failing to exploit its biggest advantage over AMD – significant overclocking headroom given controlled thermals. For non-overclocking workstation users, we defer to this chart from one of our previous noise tests on CLCs:
Above: Taken from one of our CPU cooler reviews, the higher dBA units are what would be deployed for keeping X299 CPUs reasonably cool.
Intel HEDT parts would put you, if we’re being generous, in the range of the ~50dBA CLCs at max RPMs. Existing in an ambient environment greater than ours (24C), like a case (we’ve seen up to 40C internal case ambient in some units), means that the cooler requirement boosts along with noise output.
There are more arguments for Intel to consider than just “we want to overclock higher because we’re enthusiasts,” and those arguments must be made to convince a giant like Intel to listen. Enthusiast overclocking is insignificant. Noise emissions, higher cooler costs, OEM fear of high liquid temperatures that could breach Asetek specification – these are all strong arguments against Intel’s present HEDT TIM practices. Just looking at some of the liquid temperatures hitting the 50-55C range, it’s clear that we’re rapidly approaching the 60C limiter before tripping Asetek’s out-of-spec concerns. Inside of a case, that’s easily done in heavy load scenarios (like AVX workloads). We’d implore OEM giants like Dell and HP to perform internal testing of CLC-enabled HEDT products under various workloads, particularly AVX, to determine if Intel’s TIM is forcing those companies to border on the cooler spec or forcing higher-end cooler purchases, thus potentially losing competitive edge.
If Intel is going to listen to anyone, it’s going to be OEMs.