Does thermal paste expire? 20-year-old TIM tested – no degradation seen, but poor compared to modern products
A syringe of ancient thermal paste has been tested by Igor’s Lab. With some surprise, the hardware testing stalwart reports that Arctic Cooling’s Silicone Paste worked just as well as a factory fresh industrial alternative with a similar formulation. However, Wallossek’s testing clarified that modern PC thermal pastes aimed at PC enthusiasts perform much better.
A PC hardware dealer in Germany discovered some 20-year-old thermal paste at the back of a drawer and decided to send it to Igor’s Lab. Wallossek looked at the Intel Pentium 4-era paste from Arctic Cooling and thought it was like finding an old can of soup – but one that “can’t spoil.” Without much hesitation, testing began.
The initial finding was that, since the syringe had a good seal, the paste squeezed out as it should, with an acceptable consistency.
The ingredients also piqued Wallossek’s interest. According to the packaging, Arctic Cooling’s old Silicone Paste featured 50% silicone, 20% carbon, and 30% metal oxide. This required verification, decided the veteran hardware tester and ex-Tom’s Hardware writer. So, he employed a laser-induced breakdown spectroscopy device to analyze the paste’s ingredients. Wallossek reckons that the ingredients on the label were bunk, as the analysis tool reported the paste was made from 50% silicone and 50% zinc oxide. He concluded the mention of carbon on the packaging was solely for marketing purposes…
Moving onto the comparison testing, Igor’s Lab noted that a TCTG-4.0 from MCT, an industrial “durability-focused reference paste,” performs very similarly to the antique Arctic Cooling paste. This indicates that little, if any, degradation occurred during the old paste’s slumber at the back of the PC hardware dealer’s drawer.
The Pentium 4 era paste significantly underperformed compared to a modern thermal paste, though. Wallossek tested an Intel Core i9-13900K with both the old Arctic paste and the “modern, good” Alphacool Apex thermal paste. The graph of the comparative test run (below) shows a delta of six degrees Celsius, representing 20 years of progress in thermal paste formulation. It’s not astonishing, but a very welcome improvement.
From the above tale, we might conclude that thermal paste packaging that features ‘use by’ or ‘best before’ advice from manufacturers might be wise to ignore. This may only apply if the paste is kept well, like in a sealed tube in a dark, cool drawer. I just checked my drawer and found three partly-used thermal paste syringes, and none of them seemed to have any ‘use by’ date indicated on the packaging.
For more thermal paste comparisons, look at our colossal roundup in our Best Thermal Paste for CPUs 2023: 90 Pastes Tested and Ranked feature.
