A homegrown cooling experiment is gaining attention for both its boldness and its figures. The Reddit modder T-K-Tronix bolted together a bunch of off-the-shelf M.2 SSD heatsinks onto an iPhone 17 Pro Max to make a hulking, finned contraption that’s incredibly stupid-looking and works really, really well. In 3DMark’s Stress Test—as picked by UL Solutions—it managed to retain more than 90 percent stability across 20 loops, which is a top-tier result and bears testament to just how much headroom there still is in mobile silicon when heat can be evacuated from the chassis quickly enough.
Apple’s current generation of Pro phones already employ vapor chamber cooling and an aluminum chassis to support the higher-performance A19 Pro. And that’s all this mod does: Expand the territory of heat, pass impediments to its release into the air, and throttling goes away.
What This Franken-iPhone Can Actually Do
Within a contemporary flagship, heat moves off the system-on-chip via graphite layers and a vapor chamber, which spread thermal energy out toward the frame. There, it needs to radiate out to the environment by natural convection and radiation. That final step can be the bottleneck during extended gaming or video renders. Glass is poor at conducting heat, around 1 W/m·K, and aluminum conducts it quite well (about 205 W/m·K), so you want to get it out to your metal, but it still has contact area as a constraint on dumping that heat effectively.
It’s exactly that problem M.2 SSD heatsinks solve on desktop drives: many fins and a large surface offering most of it to the airflow; little airflow needed. They are stuck to the back of the iPhone with thermal pads, as external radiators. The upshot is that there are lower surface temperatures over some of the most critical hotspots and slower escalation to the thermal limits of the SoC (the SoC’s clocks remain steadier for longer).
3DMark’s Stress Test puts a number on this—stability, that is—with its Stability feature, which centers around seeing how closely your lowest loop score lines up with your highest. In percentage terms, many high-end phones throttle to somewhere between 65% and around 85% on repeat runs, based on independent testing from the likes of Notebookcheck and GSMArena. By cracking the 90% mark, this modded unit has entered territory that’s typically reserved for dedicated gaming phones along with an active cooler.
Comparing It To Stock Cooling In Real-World Use
Vapor chambers are also good at getting the heat to spread internally, but can only do as well as the ability of the outer shell to reject it. The mod lowers the overall thermal resistance from chip to air by applying additional fins. In practical terms, this amounts to less temperature rise per workload. General thermal-engineering guidance like JEDEC’s (JESD51 series) gives us an idea of how even small increases in surface area can lead to a significant reduction in steady-state temperatures under natural convection.
There’s a second win here: higher conductivity means aluminum pairs well with the vapor chamber’s even heat distribution. Apple’s return to an aluminum frame redoubles this path relative to more insulating metals. That means when you marry it with a big fat passive heatsink, then what you have just built is an express highway for the heat from your A19 Pro to the atmosphere.
How It Compares To Clip-On Coolers And Docks
Active coolers, like the AeroActive Cooler X for the ROG Phone or RedMagic’s Ice Dock, use fans or Peltier elements to suck heat out hard off of your phone’s back panel. Third-party tests often indicate these accessories give 10%–20% more sustained performance. The SSD-heatsink method is coarser and passive, but it doesn’t introduce noise or power draw while accomplishing the same end goal—more sustained throughput with less throttling.
For pure ergonomics, clip-on coolers are still the way to go. But in terms of teaching thermal basics, the fins on this iPhone make a strong case: if you give that SoC a cooling solution built for use by giants, then benchmarks don’t immediately collapse after the first couple of minutes.
The Trade-Offs You Should Expect With This Mod
No surprise—the phone looks outrageous. But there are tangible trade-offs beyond the visual one. External heatsinks can block MagSafe accessories, wireless charging and NFC. They can detune antennas and block microphones when installed haphazardly. Pressure and adhesives on the back plate can decrease water resistance and likely cancel the warranty.
Placement also matters. The biggest wins come from targeting the largest metal regions nearest to the SoC. “Adding a heat sink over (the) camera plateau,” for example, will help in some cases but can also trap lens or sensor heat. Wrong thickness thermal pad = air gaps = performance death.
In practical use, the payoffs appear in prolonged 60 fps gaming sessions and more consistent export times for 4K video or ProRes workflows. Less droop in frequency loop-to-loop is also indicated by the 3DMark score and corresponds well with user feedback of consistent frame rates after sustained gaming running thermally intensive titles.
What This Means for Phones of the Future
Android flagships have been relying on vapor chambers for years, and Apple’s embrace tells us where the industry is going: larger spreaders, better thermal interfaces, more thermally efficient frames.
The mod here merely teases latent ability—endurance is still limited by how fast a handheld can throw an extra couple of watts into the ambient air.
We can expect to see more sophisticated internal solutions rather than bolted-on fins: larger vapor chambers, graphite stacks with higher in-plane conductivity, and smarter heat paths back out to the frame. Accessory makers are going to continue riffing on small active coolers, and they should: They do deliver measurable performance gains without turning a phone into an unfriendly porcupine in your pocket.
But as a proof of concept, this monster iPhone is irresistible. It shaves the problem down to its most basic elements and demonstrates that, given enough surface area, mobile silicon made today can keep swinging long after the scoreboard suggests most phones should be benched.
