Alphacool

Alphacool Subzero

Expert rating6.6 / 10

Model:: Alphacool Subzero
Compound Type:: High-Performance Silicone-Based
Thermal Conductivity:: 16 W/mK
Electrical Conductivity:: Non-Conductive
Package Size:: 1g / 3.5g / 20g tubes
Recommended Use:: High-end CPU/GPU (including overclocking)
Reapplication Interval:: Verify manufacturer-rated interval
Safety Notes:: None

Consumercarts is reader-supported. Learn more

Disclaimer: The price and specification of the given product may differ from the actual product. Please confirm on the retailer's website before buying.

Manufacturer: Alphacool Last updated: 2026-10-08

Where to buy

NeweggGo to store
AmazonGo to store

Alphacool Subzero Review

Subzero is Alphacool's high-performance thermal compound, rated at 16 W/mK, a figure ahead of Thermal Grizzly Kryonaut and most other non-liquid-metal pastes in this category. It's sold across a wide range of package sizes, from a small 1g trial size up to a 20g bulk option.

Thermal Performance and Conductivity

At 16 W/mK, Subzero rates ahead of Thermal Grizzly Kryonaut's 12.5 W/mK and Thermalright TFX's 14.3 W/mK, putting it among the highest-rated non-liquid-metal pastes in this category.

Compound Type and Composition

A high-performance silicone-based compound, formulated to push conductivity without moving to liquid metal's electrical conductivity risk.

Application and Consistency

Available from 1g up to 20g, Subzero's range of package sizes accommodates both single-build trial use and bulk application across multiple systems.

Electrical Safety

Non-conductive, carrying no short-circuit risk despite its high conductivity rating.

Longevity and Pump-Out Resistance

Manufacturer-rated interval isn't as prominently published as some competitors. Confirm against current Alphacool documentation before publishing a specific timeframe.

Comparison to Alternatives

Against Thermal Grizzly Kryonaut, covered elsewhere on this site, Subzero claims a meaningfully higher rated conductivity, making it worth considering for high-end builds prioritizing paste over liquid metal. Against Thermalright TFX, Subzero rates higher still, currently the highest non-liquid-metal conductivity figure in this catalog.

Who This Paste Is Actually For

High-end CPU and GPU builds, including overclocking, wanting the highest non-liquid-metal conductivity available.

Builders who want liquid metal-adjacent performance without the electrical conductivity risk.

Not for: Budget builds where Arctic MX-4 or MX-6 deliver adequate performance for less.

Not for: Extreme overclocking setups specifically requiring liquid metal's even higher conductivity ceiling.

Pending Verification

Reapplication Interval: Manufacturer-rated interval not consistently published.

Our verdict

Reviewed by Burooj Alam. Rated by us, not by users.

Expert rating6.6 / 10

A high-performance silicone-based compound from Alphacool with a strong published conductivity figure.

Best for

High-end CPU and GPU builds, including overclocking, wanting the highest non-liquid-metal conductivity available.
Builders who want liquid metal-adjacent performance without the electrical conductivity risk.

Not for

Budget builds where Arctic MX-4 or MX-6 deliver adequate performance for less.
Extreme overclocking setups specifically requiring liquid metal's even higher conductivity ceiling.

Specifications

What these specs mean

Identity and form

Brand	Alphacool
Model	Alphacool Subzero , Subzero

Thermal performance

Conductivity Source	https://shop.alphacool.com/en/shop/thermal-conductant/thermal-compound/13009-alphacool-subzero-thermal-grease-20g

Electrical and board risk

Paste Segment	Standard Paste

Compound Type	High-Performance Silicone-Based
Thermal Conductivity	16 W/mK
Electrical Conductivity	Insulating
Package Size	1g / 3.5g / 20g tubes
Recommended Use	High-end CPU/GPU (including overclocking)
Reapplication Interval	Verify manufacturer-rated interval
Safety Notes	None

FAQs

What are the key specifications of the Alphacool Subzero (High-Performance Silicone-Based/Non-Conductive/16 W/mK)?

Key specs for the Alphacool Subzero: Thermal Conductivity 16 W/mK, Thermal Conductivity Source https://shop.alphacool.com/en/shop/thermal-conductant/thermal-compound/13009-alphacool-subzero-thermal-grease-20g, Compound Type High-Performance Silicone-Based, Electrical Conductivity Insulating.

Will the Alphacool Subzero (High-Performance Silicone-Based/Non-Conductive/16 W/mK) work with my current setup?

The Alphacool Subzero (High-Performance Silicone-Based/Non-Conductive/16 W/mK) lists Thermal Conductivity is 16 W/mK. Check that against the hardware you already own before buying, since this is the field that most often decides whether a part fits.

Who is the Alphacool Subzero (High-Performance Silicone-Based/Non-Conductive/16 W/mK) best suited to?

Best suited to: High-end CPU and GPU builds, including overclocking, wanting the highest non-liquid-metal conductivity available; Builders who want liquid metal-adjacent performance without the electrical conductivity risk.

What are the drawbacks of the Alphacool Subzero (High-Performance Silicone-Based/Non-Conductive/16 W/mK)?

Not the best fit for: Budget builds where Arctic MX-4 or MX-6 deliver adequate performance for less; Extreme overclocking setups specifically requiring liquid metal's even higher conductivity ceiling.