After our launch-day investigation into delidding the 9900K and finding its shortcomings, we’ve been working on a follow-up involving lapping the inside of the IHS and applying liquid metal to close the story on improvement potential with the delid process. We’re also returning to bring everyone back to reality on delidding the 9900K, because it’s not as easy as it may look from what you’re seeing online.
We already know that it’s possible to see performance improvement, based on our previous content and Roman’s own testing, but we’ve also said that Intel’s solder is an improvement over its previous Dow Corning paste. Considering that, in our testing, high-end Hydronaut paste performs nearing the solder, that’s good news when compared to the older thermal compound. Intel also needed to make that change for more thermal headroom, so everyone benefits – but it is possible to outperform it.
“How frequently should I replace liquid metal?” is one of the most common questions we get. Liquid metal is applied between the CPU die and IHS to improve thermal conductivity from the silicon, but there hasn’t been much long-term testing on liquid metal endurance versus age. Cracking and drying are some of the most common concerns, leading users to wonder whether liquid metal performance will fall off a cliff at some point. One of our test benches has been running thermal endurance cycling tests for the last year now, since September of 2017, just to see if it’s aged at all.
This is a case study. We are testing with a sample size of one, so consider it an experiment and case study over an all-encompassing test. It is difficult to conduct long-term endurance tests with multiple samples, and would require dozens (or more) of identical systems to really build-out a large database. From that angle, again, please keep in mind that this is a case study of one test bench, with one brand of liquid metal.
We already have a dozen or so content pieces showing that delidding can improve thermal performance of Intel CPUs significantly, but we’ve always put the stock Intel IHS back in place. Today, we’re trying a $20 accessory – it’s a CNC-machined copper IHS from Rockit Cool, which purportedly increases surface area by 15% and smooths out points of contact. Intel’s stock IHS is a nickel-plated copper block, but is smaller in exposed surface area than the Rockit Cool alternative. The Intel IHS is also a non-flat surface – some coldplates are made concave to match the convex curvature of the Intel IHS (depending on your perspective of the heat spreader, granted), whereas the Rockit Cool solution is nearly perfectly flat. Most coolers have some slight conformity to mounting tension, flattening out coldplates atop a non-flat CPU IHS. For this reason and the increased surface (and contact) area, it was worth trying Rockit Cool’s solution.
At $14 to $20, this was worth trying. Today, we’re looking at if there’s any meaningful thermal improvement from a custom copper IHS for Intel CPUs, using an i7-8700K and Rockit Cool LGA115X heat spreader.
Delidding the AMD R3 2200G wasn’t as clean as using pre-built tools for Intel CPUs, but we have a separate video that’ll show the delid process to expose the APU die. The new APUs use thermal paste, rather than AMD’s usual solder, which is likely a cost-saving measure for the low-end parts. We ran stock thermal tests on our 2200G using the included cooler and a 280mm X62 liquid cooler, then delidded it, applied Thermal Grizzly Conductonaut liquid metal, and ran the tests again. Today, we’re looking at that thermal test data to determine what sort of headroom we gain from the process.
Delidding the AMD R3 2200G is the same process as for the 2400G, and liquid metal application follows our same guidelines as for Intel CPUs. This isn’t something we recommend for the average user. As far as we’re aware, one of Der8auer’s delid kits does work for Raven Ridge, but we went the vise & razor route. This approach, as you might expect, is a bit riskier to the health of the APU. It wouldn’t be difficult to slide the knife too far and destroy a row of SMDs (surface-mount devices), so we’d advise not following our example unless willing to risk the investment.
Overclocking engineer "Der8auer" has come out with his newest product: The Skylake-X Direct Die Frame cooling bracket. The bracket is intended to replace the ILM (independent loading mechanism) on the motherboard, used to act as a shim between a delidded CPU and a cooler. The goal is to not only delid the CPU and replace the compound, but also completely eliminate the heatspreader. Traditionally, the IHS would be kept post-delid, just with better compound and with removal of the silicone adhesive. In this application, you would delid the CPU, refresh the compound, remove the adhesive, and leave the IHS off, then mount it in the Skylake-X direct die bracket.
Some of our recent delid-focused content, "What We've Learned Delidding Intel CPUs," has highlighted that a light silicone adhesive seal vs. no seal vs. heavy seal can have significant impact on cooling. Heavy seals, for instance, can easily result in worse performance than stock -- even with liquid metal. We recommend not resealing the IHS at all and just allowing the cooler to retain the IHS, but a seal is sometimes needed. Shipping is a good example of this.
As we pack before CES, this is just a quick video update in a non-standard format. We decided to put together a loose video that details the practical learnings of delidding -- things we've picked up over the past few months of taking the IHS off processors. During this time, we've learned a few tricks pertaining to resealing, preventing electrical shorts and damage, and applying liquid metal. These are all things that we could have used when learning about delidding, and so we decided to compile it into one content piece. The format is less formal and in our "tear-down" setup, just with a different tone to the content.
Just a quick update for everyone: We've got a major feature -- an end-of-year special that includes a short film (something we've never done before) -- going up tomorrow at around 9AM EST. That'll be sort of an end-of-year recap of a few key components, primarily those that disappointed us.
In the meantime, while we were playing one-day roles of directors and cinematographers, we've set to work on delidding another 7980XE. This will be our third delid of the 18C CPU, with another ~4~5 delids of lower-end CPUs from the past few months. Our previous delid was for Kyle of "Bitwit," which later led to our Intel X299 VRM thermal investigation of the ASUS Rampage VI Extreme motherboard's VRM temperatures. It was an excellent opportunity for us to explore potential sideshoot content pieces in more depth, and gave us multiple samples to build a larger sample size.
We're now up to 3x 18C CPUs delidded, and are collecting data on the latest for Ed from Tech Source. The delid just completed, and we're now in the resealing stage.
Tripping VRM overtemperature isn’t something we do too often, but it happened when working on Bitwit Kyle’s 7980XE. We’re working on a “collab” with Kyle, as the cool kids call it, and delidded an i9-7980XE for Kyle’s upcoming $10,000 PC build. The delidded CPU underwent myriad thermal and power tests, including similar testing to our previous i9-7980XE delid & 7900X “thermal issues” content pieces. We also benchmarked sealant vs. no sealant (silicone adhesive vs. nothing), as all of our previous tests have been conducted without resealing the delidded CPUs – we just rest the IHS atop the CPU, then clamp it under the socket. For Kyle’s CPU, we’re going to be shipping it across the States, so that means it needs to not leak liquid metal everywhere. Part of this is resolved with nail polish on the SMDs, but the sealant – supposing no major thermal detriment – should also help.
Tripping overtemperature is probably the most unexpected side of our journey on this project. We figured we’d publish some data to demonstrate an overtemperature trip, and what happens when the VRMs exceed safe thermals, but the CPU is technically still under TjMax.
Let’s start with the VRM stuff first: This is a complete sideshoot discussion. We might expand it into a separate content piece with more testing, but we wanted to talk through some of the basics first. This is primarily observational data, at this point, though it was logged.
Running through the entire Skylake X lineup with TIM vs. liquid metal benchmarking means we’ve picked-up some very product-specific experience. Skylake X has a unique substrate composition wherein the upper substrate houses the silicon and some SMDs, with the lower substrate hosting the pads and some traces. This makes delidding unique as well, made easier with Der8auer’s Delide DieMate X (available in the US soon). This tutorial shows how to delid Intel Skylake X CPUs using the DieMate X, then how to apply liquid metal. We won't be covering re-sealing today.
Still, given the $1000-$2000 cost with these CPUs, an error is an expensive one. We’ve put together a tutorial on the delid and liquid metal application process.
Disclaimer: This is done entirely at your own risk. You assume all responsibility for any damage done to CPUs. We will do our best to detail this process so that you can safely follow our steps, and following carefully will minimize risk. Ultimately, the risk exists primarily in (1) applying too much force or failing to level the CPU, both easily solved, or (2) applying liquid metal in a way that shorts components.
Our 7900X delidding benchmarks weren’t published by coincidence: Today, we’re expanding on our liquid metal vs. Intel TIM testing with the new Intel i9-7960X and i9-7980XE CPUs, the 16C and 18C Skylake-X parts, respectively. These CPUs are Intel’s highest multithreaded performers in this segment, and are priced alongside that status – the 7960X costs $1700, with the 7980XE at $2000.
Rather than focusing entirely on delidding and thermal benchmarks, we’ll also be including power testing and some production benchmarks (Blender, Premiere). This review of the Intel i9-7960X and i9-7980XE will primarily test thermals, power, delidded thermals, liquid metal thermals, rendering benchmarks, and some synthetics.
Recapping the previous test approach for delidding & liquid metal:
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