Thank you be quiet! for sending us 1g of this liquid metal to review!

Late last year, my wife and I took advantage of an eBay refurbished sale around Black Friday to purchase each of us an extremely high-end laptop for an incredible price.  We ended up getting Acer Predator Helios 18s, with the Intel Core i9 14900HX CPU and NVIDIA RTX 4090 mobile graphics.  The system specifications are incredible, with 18" 2560x1600 250Hz miniLED screens, and fantastic performance all around.  Unfortunately, they tend to overheat at the drop of a hat when used in Performance or Turbo modes, which is required to get the most out of that GPU, so I was hoping a proper repaste would solve our problems with these laptops.  Unfortunately, solve our problems it did not.  But it was not a total waste.

I was convinced, based on comments that I saw online, that Acer often did not do a particularly good job applying thermal compound to their laptops.  There's no way that Acer just didn't give these huge laptops (18" laptops are big!) enough heat sink area, right?  Hoping to solve this, I reached out to be quiet! for the opportunity to redo the stock liquid metal with all new using their DC2 Pro, and hopefully show how much better things would be with it replaced.  They graciously accepted.  

When it comes to thermal compounds, there are a few main types.  First is the basic thermal paste.  This has been used for the vast majority of CPU coolers for many decades.  The thermal conductivity is somewhere between 5 and 10 W/mK.  (It's watts per meter-Kelvin, which measures the rate of heat transfer.)  Most paste is non-conductive, making it easy to use and work with.  

Liquid metal trades this ease of use for a much, much higher thermal conductivity.  Instead of that 5-10 W/mK conductivity, it's around 80 W/mK.  This means that if all goes according to plan, it can help lead to a nearly perfect heat transfer.  The biggest downside is that if a single drop of liquid metal gets in the wrong place, it can destroy hardware.  I tried some I had gotten in the past with my desktop PC, and had to replace my motherboard when a tiny ball of it got under the CPU socket.  This stuff is not to be trifled with, and must be handled with utmost care.

Other thermal compounds include thermal pads, thermal putty, and thermal goop.  These are often used for parts that generate heat, but to much lesser extents.  This includes things like video RAM (VRAM) chips, VRMs (voltage regulator modules), and similar parts.  It's still important to cool these, but something like liquid metal is overkill (or outright dangerous) with them.

Laptops are some of the most difficult computers to keep cool.  Especially with high-end models, they generate an incredible amount of heat in a very small space.  These days, it's actually the CPU that causes the most problems.  Pro tip: If you are buying a gaming laptop, please strongly consider an AMD CPU if it's available in the performance tier you are looking for.  You will thank me later.

Intel, for the last several years, has had both a dominant position in the high-end laptop market, and has also made some of the objectively worst CPUs when considering performance per watt compared to the competition.  While they might top the charts in pure performance in some cases, the cost to get there is an incredibly high power consumption, to the point that their CPUs are degrading and Intel is being forced to ship replacements to customers.  (This applies mostly to their desktop chips, but the laptop models use the exact same die, so there is no logical reason this couldn't happen on laptops also).  Intel's 13th and 14th generation CPUs have been a disaster unlike almost anything else in recent memory, not to mention a really expensive mistake.

In order to prevent permanent damage to their processors, Intel has shipped microcode updates that limits the maximum voltage to the CPU die.  (If you own a laptop or desktop with a 13th or 14th gen CPU inside, please update the BIOS immediately.)  Unfortunately, Acer has not shipped that update for my model.  Fortunately, third-party modders have released an unlocked BIOS that allows advanced users to limit the maximum voltage there; I have done this by limiting my CPU max voltage to 1.4V.  (Before this change, I would see spikes of around 1.55V.)  This is outside of the stock configuration, and that does somewhat invalidate my testing compared to others with the same laptop, but I am not going to knowingly damage my CPU for a test since I plan to keep this laptop for a while.  It does lower maximum performance some, but to me that longevity is more than worth the sacrifice.

On this line of laptops, only the CPU cooler interface uses liquid metal.  That is the most common component cooled this way, because of the high heat generation.  NVIDIA has done a much better job at keeping their GPU's heat generation under control, so liquid metal is unnecessary.  It's important to note that if a component is not designed to be used with liquid metal, it can and will be damaged if it's used.  For example, a heat sink with an aluminum or copper plate will corrode if liquid metal is used.  Most commonly, surfaces designed for liquid metal will be nickel-plated, which is safe to use together.  On my laptop, only the CPU part of the heat sink has the required plating.  (My desktop CPU cooler, the be quiet! Silent Loop 3, also has the required nickel plating to use liquid metal.)  On my Acer, they include special spacers around the CPU to prevent the liquid metal from escaping.  Without this, it could escape and drip onto other components, which could easily damage the system.  

When I planned my repaste, I purchased quite a bit outside of just this review sample of liquid metal.  I bought some PTM (a new type of phase-changing thermal pad) for the GPU, and some thermal putty and goop for the rest of the components.  This other stuff ended up being much more expensive than what the liquid metal would cost, thanks to be quiet!'s competitive pricing for the DC2 Pro, and how much of that other stuff I needed.  Thermal goop and especially putty does not go nearly as far as it appears like it should because of how thick it is.  But at least twice what you think you might need.  PTM is just a thin sheet, so you can accurately measure the die area and buy just what you need.  It's worth noting that if you mess up and need to reapply, you can't reuse PTM at all, so plan that into your budget.

I spent close to $50 for the 'other' cooling products, though I ended up wasting the thermal putty trying to get better results; more on that later.  The PTM and K5-Pro thermal goop I purchased ended up to be right around $30.  With the DC2 Pro added in, what I did would cost around $45 for everything.