Precision-Cooled: The Hidden Engineering Behind Every Nerdaxe Hydro Cold Plate

If you’ve spent any time mining at home, you know ASICs (Application-Specific Integrated Circuits) can crank out serious heat for such small, specialized machines.

They’re purpose-built chips designed to do one thing (like hashing Bitcoin) really, really fast. But that kind of speed doesn’t come free. Every time current flows through the chip’s silicon, it creates heat (thanks to something called resistive or “Joule” heating). And if you don’t deal with that heat properly? You’ll end up with throttled performance, more errors, and a shorter lifespan for your gear.

That’s where cold plate design becomes mission critical.

The First Line of Defense: Thermal Paste

Before we even get to the metal and coolant, let’s talk about thermal paste. Between your ASIC chip and the cold plate, you’ve got microscopic gaps that trap air. And air? Terrible at moving heat.

A high-quality thermal paste, such as the one we picked for Nerdaxe Hydro with 18 W/m·K conductivity, spreads out and fills in all the tiny air gaps between the chip and the cold plate, making sure heat flows smoothly from one to the other.

Upgrading just your thermal paste could drop temps by 5–10°C. That’s more uptime, more hashes, and a longer life for your ASICs.

Copper vs Aluminum: Why We Go Heavy

Next up—the base material. A lot of standard heatsinks and cold plates you’ll find out there are made from aluminum. It’s lightweight, cheap, and doesn’t rust, so it gets the job done for basic cooling needs and for large, industrial-sized miners where copper is prohibitively expensive. Aluminum’s thermal conductivity sits around 205 W/m·K, which is decent for general use.

But when you're cooling small home miners with high-power ASICs and want to squeeze out every bit of efficiency, copper wins. With thermal conductivity closer to 385 W/m·K, nearly double that of aluminum, copper spreads heat more evenly across the cold plate, cutting down on hot spots and helping your coolant pull heat away faster and more effectively. That means more even cooling, fewer hot spots, and a cooler junction temperature overall. And with the small, compact size of a home miner, the cost difference between copper and aluminum is a no-brainer.

Let’s say you have two cold plates (same design, same thermal paste) but one’s aluminum and the other’s copper. Once the ASIC starts working hard, the aluminum plate will heat up unevenly, creating hot spots right where it contacts the chip. This is because aluminum doesn’t spread heat as quickly. Copper, on the other hand, distributes that heat much more evenly across its surface. That means lower peak temps at the ASIC itself. And since the water flowing through the cold plate sees a more consistent temperature, it pulls heat away more efficiently. Overall, the copper setup ends up with lower thermal resistance and better cooling performance.

We use copper for a reason—it works better. Yes, it’s heavier. Yes, it costs a little more. But in a setup where quality matters, that trade-off is 100% worth it.

Microfins Matter: How We Make Every Drop of Coolant Count

Even with copper’s excellent heat conductivity (385 W/m·K), a flat copper base on its own just isn’t enough to get the most out of your cooling system. To really move heat efficiently from the cold plate into the coolant, we use microfins—tiny, tightly packed ridges inside the plate. These microfins massively increase the surface area and stir up turbulence in the coolant flow, so the liquid touches more of the copper and pulls heat away faster. Without them, you’d get a smooth, laminar flow that acts more like an insulator than a heat mover.

But designing the right microfin layout isn’t just a guessing game, it’s a balancing act. Here’s what we tune to get it just right:

1. Baseplate Thickness

Too thin and it can’t spread heat well, so hot spots form fast. Too thick and it slows down thermal response. With the Nerdaxe Hydro, we’ve found the sweet spot between strength and fast heat spreading.

2. Microfin Height

Taller fins mean more surface area and better cooling, but they also increase resistance to flow, making your pump work harder. Our design incorporates the ideal fin height for the given size and heat load of the Nerdaxe Hydro. This keeps things efficient without adding too much pressure drop.

3. Fin Density (Spacing)

More fins per inch (FPI) gives you more surface area, but if they’re packed too tight, coolant can’t move well, leading to dead spots and reduced cooling efficiency. Too few fins, and you lose heat transfer surface area, leaving efficiency gains on the table. Combining the appropriate fin height with the ideal fin density maximizes the cooling power packed into each Nerdaxe Hydro.

4. Coolant Flow Rate

You want your coolant flowing fast enough to stay turbulent (that’s where heat transfer is best), but not so fast it overwhelms your pump, gets noisy, or uses too much power. Too slow of a flow rate and you get insulating layers of coolant. Too fast and the return isn’t worth the added pump strain.

All of these elements interact. A thicker baseplate might change your fin height and density, but then your flow will need to adjust to keep temps even. More fins? You better have the pump and tubing to back it up.

That’s why we use computational fluid dynamic (CFD) simulations to test and tune everything.

The end goal? Lower overall thermal resistance, from the chip all the way through the cold plate and coolant loop. Each piece plays a part, and cutting down just one of those resistances helps the whole system run cooler and more efficiently.

Bottom line: great cooling is all about the details, and we’ve obsessed over every one.

It's All Connected: System-Level Thinking

When you’re running an AIO cold plate setup with copper microfins and high-performance thermal paste, you can’t just stop there. Instead, you have to think about the whole loop. Your radiator, fans, pump, tubing, and reservoir all need to work together to keep coolant temps low enough to handle the heat coming off those ASICs.

We’ll be breaking down more design details in future blogs, so make sure you follow us to stay up to date when those drop.

Bottom Line: Why It Matters

It’s easy to overlook cooling when you’re chasing hash rate or tweaking firmware—but don’t. Cooling is performance. The better your heat is managed, the more consistent your miner runs, the fewer errors you deal with, and the longer your hardware lasts.

At Nerdaxe Hydro, we obsess over every detail, from thermal paste to copper thickness, because we mine bitcoin too. We know the pain of throttled rigs, overheated chips, and underperforming gear. That’s why we build our cold plates with the same care and precision we’d want in our own setups.

Think cooling doesn’t matter? Think again.

Ready to upgrade your miner with cold plate tech built for real miners? Check out Nerdaxe Hydro and see how we keep our ASICs cool, quiet, and crushing it.