MSI GeForce RTX 5090 SUPRIM LIQUID SOC Review – Grilling is now done away from case

1 - Introduction, overview and technical data 2 - Test system and equipment 3 - Teardown: PC, components and cooler 4 - Material analysis and TIMs 5 - Gaming performance 6 - Power consumption, transients and PSU recommendation 7 - Temperatures und clock rates 8 - Thermal imaging and modding 9 - Fan curves and noise 10 - Summary and conclusion

As already announced, I will now also measure the thermal conductivity materials of the MSI RTX 5090 SUPRIM Liquid with my Nanotestt TIMA5. This procedure is probably unique in its precision and depth of detail, as the TIMA5 enables a precise analysis of the thermal properties and thus allows a differentiated evaluation of the thermal pads used and the other thermal interface materials. These measurements go beyond conventional tests and provide detailed insights into the efficiency of heat transfer, which is of central importance for a card of this performance class. The results will not only evaluate the performance of the materials themselves, but will also show their influence on the overall cooling of the card and possible optimization potential.

Phase transition pad Honeywell PTM 7950

Since I only found remnants on the GPU, I’m using my own measurement of an unused pad from my archive, as I’ll be putting it back on during assembly. With over 6.3 W/mK, this durable pad is a better solution than almost all available pastes.

The thermal pads on the memory modules

The thermal pad used, with a thermal conductivity of 9.12 W/mK, stands out for its exceptional performance and consistency. It differs from conventional pads due to its dry, almost rolled texture, which is reminiscent of a compacted thermal putty. This material offers some decisive advantages that not only influence the thermal efficiency, but also the mechanical load on the card. The dry and at the same time flexible consistency of the pad enables optimum adaptation to the uneven surfaces of the components and the cooler. This adaptability achieves a maximum contact surface, which significantly improves heat transfer. At the same time, the material structure reduces the pressure exerted on sensitive components such as VRAM modules or voltage converters. This significantly reduces the risk of mechanical damage or stress cracks.

The fact that the pad is good and suitable can also be seen from the almost linear curve, where the thermal resistance also behaves perfectly with increasing pressure and lower layer thickness. Another advantage of the material is its stability. In contrast to conventional, softer pads, which often tend to “bleed” or “oil out” – i.e. the release of liquid components under pressure or heat – this pad remains dimensionally stable and retains its thermal properties even under long-term stress. This not only increases the service life of the pad itself, but also the stability of the entire thermal solution. The material analysis shows that, similar to thermal conductive pastes, aluminum and zinc oxide as well as a silicone-based matrix are used.

The remaining thermal pads (VRM, coils, other active components)

The other thermal pads used, with a thermal conductivity of only 3.3 W/mK, belong to the lower middle class and only meet basic heat transfer requirements. The silicone-free matrix used in these thermal pads is based on special polymers that represent an alternative to conventional silicone-based materials. Such polymers offer several advantages, but also specific challenges when used as a heat conducting material.

Compared to silicone, silicone-free polymers are characterized by greater stability under thermal and mechanical stress. They are less likely to bleed or dry out under pressure or heat, resulting in a longer pad life and more consistent thermal performance. This is particularly important in applications such as graphics cards, where consistent heat transfer and material stability over an extended period of time are critical. Despite these advantages, silicone-free pads are often softer and less dimensionally stable, which reduces their mechanical resilience. They can deform under pressure and thus impair their thermal performance, especially if the pads are applied thinly or unevenly. This deformation is illustrated in the pads described here by the sharp drop in the performance data curve under pressure.

Silicone-free polymers are therefore an interesting solution for thermal pads, as they offer chemical stability and long-term reliability. However, their use requires careful adaptation to the specific requirements, especially when it comes to pressure distribution and mechanical resilience. Optimizations in the material composition could minimize these weaknesses and bring out the advantages even better.

Analysis of the radiator surface

The supplied microscopy image and LIBS show a detailed image of the surface under a stereo microscope at 100 µm scale. The analysis was carried out using LIBS and shows 100 % copper content with no measurable impurities. It is therefore not a coated alloy or a copper-aluminum core system, but solid, high-purity copper that presumably corresponds to the ETP (Electrolytic Tough Pitch) or even OFHC (Oxygen-Free High Conductivity) class. The homogeneous microstructure underlines the thermal conductivity of this block, which is likely to be over 390 W/mK.

The milled structure is functional, but not ground or nickel-plated. This has advantages and disadvantages: The direct copper surface offers the highest thermal conductivity, but tends to oxidize if it comes into contact with atmospheric oxygen for a long time. MSI seems to have deliberately decided against a nickel coating, probably to avoid possible galvanic effects with the cooling liquids or pad materials used. The visible scratches are mostly superficial and typically occur when the protective film is removed or on first contact with pad materials. A real deviation in flatness is not recognizable.

That finally concludes this part and we’ll play a round. One page turn please!