The GPU core gets all the attention, but the voltage regulation modules (VRMs) are equally critical — and often run hotter. VRMs convert the 12V from the power supply down to the 0.8-1.2V the GPU core needs, and this conversion generates significant heat. Without proper thermal management, VRM overheating causes GPU instability, throttling, and in extreme cases, component failure.
This guide covers how to select thermal pads specifically for GPU VRMs, including conductivity requirements, material recommendations, and thickness considerations.
Why VRMs Need Different Thermal Pads Than the GPU Core
VRMs present different thermal challenges than the GPU core:
- Multiple heat sources — a GPU VRM section typically has 6-12 individual phases, each with MOSFETs, inductors, and capacitors. The thermal pad must cover all of these components with a single surface or multiple pads.
- Uneven height — MOSFETs, inductors, and capacitors are different heights. The thermal pad must conform to this uneven topology while maintaining contact with all surfaces. This is where soft, high-deflection gap fillers excel.
- Lower maximum temperature — VRM MOSFETs typically have a maximum junction temperature of 125°C, but performance degrades above 100°C. Keeping VRMs below 90°C under load ensures stable power delivery.
- Electrical isolation — unlike the GPU core, VRM components are electrically live. The thermal pad must provide electrical isolation between the VRM components and the heatsink, preventing shorts.
Conductivity Requirements for VRM Thermal Pads
The thermal conductivity needed for VRM cooling depends on the GPU’s power draw:
- Low-power GPUs (75-150W): 3-5 W/mK is sufficient
- Mid-range GPUs (150-250W): 5-8 W/mK recommended
- High-end GPUs (250-350W): 8-12 W/mK for sustained loads
- AI / datacenter GPUs (350W+): 12+ W/mK for continuous high-TDP operation
For more on why thermal conductivity alone does not tell the full story, see our guide on thermal conductivity and what else matters.
Recommended Materials for GPU VRM Thermal Pads
High-Deflection Gap Fillers (Best for Uneven VRM Topology)
Materials with high deflection under low pressure conform to the uneven surfaces of VRM sections:
- Bergquist Gap Pad 5000S35 (5 W/mK) — good general-purpose VRM pad
- THERM-A-GAP PAD 60 (6 W/mK) — higher conductivity option
- T-Global TG-A9000 — ultra-soft, high conformability
- TFLEX HD300 — high deflection Laird gap filler
See our guide on TFlex HD thermal pads for more on high-deflection materials.
High-Conductivity Pads (Best for High-Power VRMs)
For GPUs with high power draw, prioritize conductivity:
- T-top91-s (13 W/mK) — high conductivity gap filler
- T-top98-s (18 W/mK) — ultra-high conductivity
- Henkel GAP PAD TGP 12000ULM (12 W/mK) — ultra-low modulus for maximum conformability
Electrically Isolating Pads
If the heatsink makes direct contact with VRM components, use a pad that provides electrical isolation:
- CHO-THERM T500 — silicone fiberglass insulator with 4 W/mK
- CHO-THERM T609 — higher conductivity silicone insulator
- Sil-Pad 2000 — high W/mK thermal interface pad
For more on the difference between Sil-Pads and Gap Pads, see our guide on Sil-Pad or Gap Pad.
Thickness Considerations for VRM Thermal Pads
VRM thermal pads are typically thicker than VRAM pads because of the height variation across VRM components:
- 1.0-1.5 mm for VRMs with minimal height variation
- 2.0 mm for VRMs with significant height differences between MOSFETs and inductors
- 2.5-3.0 mm for VRMs with large gaps to the heatsink
The pad must be thick enough to contact all VRM components simultaneously. If a 1.0 mm pad contacts the tallest component but misses the shortest, the shorter components will overheat.
Related Reading
For thermal pad requirements in other power delivery applications, see our guide on DC/DC converter thermal pads and thermal gap fillers in power supplies.
Sourcing VRM Thermal Pads
NEDC supplies VRM thermal pads from all major manufacturers and can die-cut custom shapes to match your VRM layout. For custom-cut VRM pads, request a quote with your dimensions and material preferences, or visit our thermal pads page for the full material catalog.