Arctic MX-4 Thermal Compound, 4g Syringe, 8.5W/mK

ARCTIC MX-4 4g Thermal Paste – Premium CPU & GPU Thermal Compound

The ARCTIC MX-4 4g thermal paste (ACTCP00002B) is a premium thermal interface compound designed to improve heat transfer between processors, graphics chips and compatible heatsinks or cooling systems.

Its microparticle-based formula fills the microscopic surface imperfections that naturally exist between a CPU or GPU and the cooler base. By replacing insulating air gaps with a thin thermal interface layer, MX-4 helps heat move efficiently from the chip into the heatsink.

MX-4 is metal-free, electrically non-conductive and non-capacitive, making it considerably more forgiving to apply than electrically conductive compounds or liquid metal. ARCTIC also formulates MX-4 for long-term stability with excellent non-drying and non-bleeding characteristics.

This exact version contains 4 grams of grey ARCTIC MX-4 in a resealable syringe, providing enough material for multiple typical applications depending on processor size and the quantity applied.

MPN: ACTCP00002B   |   Content: 4g   |   Colour: Grey   |   EAN: 4895213701655

Key Features of ARCTIC MX-4 4g

• 4g premium thermal compound
• Designed for CPUs, GPUs and other suitable chip-to-heatsink applications
• Metal-free formula
• Not electrically conductive
• Not electrically capacitive
• Helps fill microscopic gaps between chip and cooler surfaces
• Excellent non-drying properties
• Excellent non-bleeding properties
• Easy-to-control consistency for straightforward application
• Density: 2.50g/cm³
• Viscosity: 31,600 poise
• Volume resistivity: 3.8 x 10¹³ Ω·cm
• Continuous-use temperature: -50°C to +150°C
• Grey colour
• Resealable syringe
• Unopened storage life of up to 8 years
• Safe for contact with aluminium compared with corrosive liquid-metal compounds
• Suitable for air coolers and compatible liquid-cooling cold plates
• ARCTIC Authenticity Check support
• ARCTIC 6-year manufacturer warranty, subject to warranty terms

What Does Thermal Paste Actually Do?

CPU heat spreaders and cooler bases can appear perfectly smooth to the eye, but their surfaces contain microscopic imperfections.

If two dry surfaces are pressed together, tiny air pockets remain between them. Air is a poor thermal conductor, so these gaps can reduce the efficiency with which heat passes from the processor into the cooler.

Thermal paste fills these microscopic spaces and creates a more effective thermal interface between the two surfaces.

Does Thermal Paste Cool the CPU by Itself?

No. Thermal paste does not replace the CPU cooler.

Its job is to improve thermal contact between the processor and the heatsink or water-block cold plate. The cooler itself remains responsible for moving the heat away from the processor.

Suitable for CPU Cooling

ARCTIC MX-4 can be used when installing or servicing a compatible desktop or laptop CPU cooling system.

Common situations include:

• Installing a new CPU cooler
• Changing processors
• Removing and reinstalling a heatsink
• Servicing an older PC
• Replacing aged thermal compound
• Rebuilding or upgrading a gaming PC
• Maintaining workstation systems

Can ARCTIC MX-4 Be Used on Intel CPUs?

Yes. MX-4 is not tied to a particular CPU socket or processor manufacturer.

It can be used as a thermal interface on compatible Intel processor and cooler installations where conventional thermal paste is appropriate.

Can ARCTIC MX-4 Be Used on AMD Ryzen CPUs?

Yes. MX-4 can also be used with compatible AMD processors including Ryzen platforms.

The thermal paste itself does not depend on whether the processor uses AM4, AM5 or another compatible CPU socket.

Suitable for GPU Thermal Maintenance

ARCTIC also identifies MX-4 as suitable for transferring heat from GPU chips into their cooling assemblies.

This can make it useful during graphics-card maintenance where the original thermal compound needs replacing and conventional thermal paste is specified for the GPU contact surface.

Can I Use MX-4 When Repasting a Graphics Card?

Yes, on suitable GPU-to-heatsink contact surfaces.

However, graphics cards may also use thermal pads on VRAM, VRM components and other areas. Thermal paste should not automatically be substituted for thermal pads because they perform different functions and bridge different gap sizes.

Metal-Free and Electrically Non-Conductive

One of the key advantages of ARCTIC MX-4 is its metal-free formulation.

ARCTIC confirms that MX thermal pastes are neither electrically conductive nor capacitive.

This makes MX-4 more forgiving to work with than conductive compounds, particularly for beginners installing or servicing PC cooling hardware.

Can ARCTIC MX-4 Cause an Electrical Short Circuit?

MX-4 itself is not electrically conductive, so accidental small amounts around the processor do not present the same electrical-short risk associated with conductive thermal compounds.

Good installation practice is still to keep thermal paste on the intended contact area and clean away unnecessary excess.

Is MX-4 Safer to Apply Than Liquid Metal?

For most conventional PC cooling applications, MX-4 is significantly easier and more forgiving to handle than liquid metal.

Liquid-metal compounds are electrically conductive and can also react with certain cooler materials. MX-4 does not have these same electrical and material-compatibility concerns.

Non-Capacitive Formula

ARCTIC also confirms that its thermal paste is not electrically capacitive.

This reinforces MX-4's suitability for normal CPU and GPU maintenance where users want an electrically safe conventional thermal interface material.

Safe for Aluminium Cooler Surfaces

ARCTIC specifically states that its MX thermal pastes can come into contact with cast aluminium without causing the corrosion damage associated with liquid metal.

This makes MX-4 suitable for a broad range of conventional aluminium and copper cooling designs where thermal paste is required.

Can MX-4 Damage Aluminium Like Liquid Metal?

No. ARCTIC states that its MX thermal compounds do not create the corrosion issue that can occur when incompatible liquid-metal compounds are used with aluminium.

Easy Application for Beginners and Experienced Builders

ARCTIC designed MX-4 with a consistency that is straightforward to apply.

The syringe allows the user to control the amount placed on the processor before the cooler is installed.

How Much ARCTIC MX-4 Should I Apply?

The aim is to create a thin, complete thermal interface layer between the processor and cooler rather than an excessively thick layer of paste.

ARCTIC explains that several application techniques can work, including placing compound in the centre and allowing cooler mounting pressure to spread it, manually spreading the compound, or using another appropriate pattern.

The important result is that the relevant contact surface receives sufficient coverage without creating unnecessary excess.

Is More Thermal Paste Better?

No. Thermal paste is intended to fill microscopic imperfections rather than create a thick insulating layer between the CPU and cooler.

Applying far more paste than necessary does not automatically improve cooling.

4g Syringe for Multiple Applications

This product contains 4 grams of MX-4.

A few grams of thermal paste can normally cover multiple typical processor installations, although the exact number of applications depends on the size of the chip or heat spreader and how much compound is used each time.

Is 4g of Thermal Paste Enough for One CPU?

Yes. A normal CPU installation requires only a small amount of thermal paste, so a 4g syringe contains considerably more material than is required for a single typical application.

Resealable Syringe

The MX-4 syringe can be resealed after use.

ARCTIC specifically highlights its resealable packaging as helping prevent the unused compound from drying out prematurely.

How Should I Store the Remaining MX-4?

After use, clean the syringe tip if necessary, replace the cap securely and keep the product properly closed and stored under suitable conditions.

A resealed syringe can then remain available for future cooler installations and servicing.

Up to 8 Years Unopened Shelf Life

ARCTIC states that its thermal paste can be stored for up to 8 years while unopened.

The resealable syringe is also designed to reduce premature drying after the first application.

Does ARCTIC MX-4 Expire?

Like other thermal-interface materials, MX-4 should be checked before using an old syringe.

ARCTIC specifies up to eight years of storage when unopened. Once in service, there is no single replacement interval that applies to every PC.

How Often Should Thermal Paste Be Replaced?

ARCTIC does not prescribe a universal fixed replacement interval for applied thermal paste.

Instead, it recommends considering replacement when there are noticeable changes in:

• CPU or GPU temperatures
• Cooling-fan noise
• System performance
• General cooling behaviour

Thermal paste should also be reapplied whenever a cooler is removed and the original thermal interface has been disturbed.

Long-Term Non-Drying and Non-Bleeding Performance

ARCTIC describes MX-4 as having excellent non-drying and non-bleeding properties.

This is important because thermal compound must remain correctly positioned between the chip and cooler while being exposed to repeated heating and cooling cycles over long periods of use.

Continuous-Use Temperature from -50°C to +150°C

The current ARCTIC specification gives MX-4 a continuous-use temperature range of:

-50°C to +150°C

This describes the operating range of the thermal-interface material itself rather than the safe operating temperature of a CPU or GPU.

Does the +150°C Rating Mean My CPU Can Safely Run at 150°C?

No.

The -50°C to +150°C figure is the continuous-use specification for MX-4.

Processors and graphics chips have their own thermal limits, and those manufacturer limits must always take priority.

2.50g/cm³ Density

ARCTIC specifies an MX-4 density of 2.50g/cm³.

Density is a physical property of the compound and should not be confused with thermal conductivity or cooling performance.

31,600 Poise Viscosity

The current manufacturer specification lists a viscosity of 31,600 poise.

This contributes to the consistency that allows MX-4 to remain where applied while still spreading into a thin interface layer under cooler mounting pressure.

High Electrical Volume Resistivity

ARCTIC lists a volume resistivity of:

3.8 x 10¹³ Ω·cm

This specification supports ARCTIC's description of MX-4 as an electrically non-conductive thermal compound.

What Is the Thermal Conductivity of ARCTIC MX-4?

ARCTIC currently does not publish an official W/mK thermal-conductivity number for MX-4.

The manufacturer deliberately stopped using thermal-conductivity figures as a primary marketing specification because test methods and published values across the thermal-paste market can be inconsistent or misleading.

For this reason, MX-4 should be evaluated using the manufacturer's actual product design, real cooling performance and verified physical specifications rather than an unofficial W/mK figure.

Is ARCTIC MX-4 Rated at 8.5W/mK?

8.5W/mK should not be presented as the current official ARCTIC specification.

Older reseller listings frequently quote an 8.5W/mK value for MX-4, but ARCTIC's current technical specification deliberately does not give MX-4 a W/mK figure.

For an accurate current product listing, the Memox page should therefore avoid advertising MX-4 as “8.5W/mK”.

Why W/mK Alone Does Not Determine CPU Temperature

Even where a thermal-conductivity number is available, real-world CPU temperature is influenced by much more than the thermal compound.

Important factors include:

• CPU or GPU power consumption
• Cooler design
• Cooler mounting pressure
• Thermal paste thickness
• Contact-surface flatness
• Fan speed
• Radiator or heatsink size
• PC case airflow
• Ambient room temperature
• Processor boost behaviour

Compatible with Air CPU Coolers

MX-4 can be used between a compatible CPU and the cold plate or base of a conventional air cooler.

This includes tower coolers, low-profile coolers and other conventional heatsink designs where standard thermal paste is required.

Compatible with AIO Liquid Coolers

MX-4 can also be used with compatible AIO liquid coolers.

The compound sits between the processor's heat spreader and the AIO cold plate in exactly the same basic way that it interfaces with an air cooler.

Do I Need MX-4 If My Cooler Already Has Pre-Applied Paste?

If a new CPU cooler already has untouched factory-applied thermal compound, additional paste normally should not be applied on top of it.

MX-4 becomes useful if the factory compound is removed, the cooler is reinstalled later, or fresh paste is otherwise required.

Suitable for PC Upgrades and Maintenance

A 4g syringe is useful to keep with PC-building and servicing tools because fresh thermal compound is often required when:

• Changing CPU coolers
• Replacing a motherboard
• Upgrading a processor
• Servicing a graphics card
• Cleaning an older PC
• Reinstalling a heatsink
• Diagnosing abnormal processor temperatures

How to Apply ARCTIC MX-4

1. Switch off the computer and disconnect it from power.
2. Remove the cooler according to the cooler and motherboard manufacturer's instructions.
3. Remove the old thermal compound from the CPU and cooler contact surface.
4. Ensure both contact surfaces are clean and free from old paste or debris.
5. Apply an appropriate small amount of MX-4 to the processor.
6. Install the cooler evenly using the correct mounting hardware.
7. Tighten the cooler according to its manufacturer's recommended installation sequence.
8. Reconnect the cooling fan or pump connections before powering the system back on.
9. Monitor CPU or GPU temperatures after installation to confirm correct cooler contact and operation.

How to Remove Old Thermal Paste

Old thermal compound should be removed before applying a fresh layer.

ARCTIC recommends its MX Cleaner for removing dried thermal-paste residue. Whichever suitable cleaning method is used, the CPU and cooler contact surfaces should be clean before new MX-4 is applied.

Can I Put New MX-4 Directly on Top of Old Thermal Paste?

It is better to remove the old compound first.

Mixing a new layer with old or partially dried material can create an uneven thermal interface. Cleaning the surfaces allows the fresh compound to make consistent contact between the processor and cooler.

Replace Thermal Paste After Removing the Cooler

If the heatsink or cold plate has been separated from the CPU after the paste has been installed, fresh thermal compound is recommended before final reassembly.

Removing the cooler can disturb the original paste layer and create new air pockets when the cooler is reinstalled.

MX-4 vs Liquid Metal

MX-4 and liquid metal are different categories of thermal-interface material.

Liquid metal can provide very high thermal performance in specialised applications, but it is electrically conductive and requires considerably greater care regarding component and cooler materials.

MX-4 is designed as an easy-to-use conventional thermal compound that is metal-free, electrically non-conductive and safe for a much wider range of normal PC installations.

MX-4 vs Thermal Pads

Thermal paste and thermal pads should not automatically be treated as interchangeable.

MX-4 is intended to form a very thin interface between closely contacting surfaces such as a processor and cooler.

Thermal pads are generally used where a larger physical gap needs to be bridged, such as between memory chips, VRM components and heatsinks.

No Socket-Specific Compatibility Requirement

Unlike a CPU cooler mounting bracket, thermal paste itself is not tied to a particular socket.

MX-4 can therefore be used across a wide range of compatible Intel and AMD platforms, including new and older desktop systems, provided conventional thermal paste is suitable for the cooling interface.

ARCTIC Authenticity Check

Thermal compounds such as MX-4 are frequently copied, so ARCTIC provides an Authenticity Check system for supported retail packaging.

The appearance of genuine MX-4 packaging has also changed over the years. ARCTIC states that packaging revisions do not necessarily indicate a different formula.

Has the MX-4 Formula Changed?

ARCTIC states that although MX thermal-paste packaging has changed several times, the MX-4 formula has remained unchanged.

Current Technical Specifications

• Brand: ARCTIC
• Product: MX-4
• Manufacturer Part Number: ACTCP00002B
• Content: 4g
• Product Type: Thermal compound / thermal paste
• Colour: Grey
• Metal-Free: Yes
• Electrically Conductive: No
• Electrically Capacitive: No
• Density: 2.50g/cm³
• Viscosity: 31,600 poise
• Volume Resistivity: 3.8 x 10¹³ Ω·cm
• Continuous-Use Temperature: -50°C to +150°C
• Official Current Thermal-Conductivity Figure: Not published by ARCTIC
• Unopened Shelf Life: Up to 8 years
• Container: Resealable syringe
• EAN / GTIN: 4895213701655
• UPC: 872767009585
• Manufacturer Warranty: 6 years, subject to ARCTIC warranty conditions

Important Things to Know Before Buying

• This is the exact ACTCP00002B 4g MX-4 version.
• The syringe contains 4 grams of thermal compound.
• This version does not include a spatula.
• MX-4 is metal-free.
• MX-4 is not electrically conductive.
• MX-4 is not electrically capacitive.
• The colour is grey.
• Continuous-use temperature is -50°C to +150°C.
• Density is 2.50g/cm³.
• Viscosity is 31,600 poise.
• Volume resistivity is 3.8 x 10¹³ Ω·cm.
• ARCTIC currently does not publish an official W/mK rating for MX-4.
• The commonly repeated 8.5W/mK figure should not be treated as the current manufacturer specification.
• Unopened thermal paste can be stored for up to 8 years according to ARCTIC.
• The syringe is resealable.
• Old thermal paste should be cleaned away before a fresh application.
• A fresh application is recommended when a cooler has been removed and reinstalled.
• Thermal paste should not be used as a substitute for thermal pads where a physical component gap must be bridged.

What's Included?

• 1 x ARCTIC MX-4 4g thermal compound syringe – ACTCP00002B

Spatula, MX Cleaner, CPU cooler and other accessories are not included with this exact ACTCP00002B version unless specifically stated separately.

Why Choose ARCTIC MX-4 4g Thermal Paste?

The ARCTIC MX-4 has become a popular conventional thermal compound because it combines strong real-world thermal-interface performance with straightforward and electrically safe application.

Its metal-free, non-conductive and non-capacitive formulation makes it suitable for users who want to avoid the electrical risks associated with liquid metal while still improving contact between a CPU or GPU and its cooler.

The 4g resealable syringe provides enough material for multiple typical maintenance or PC-building jobs, while ARCTIC's excellent non-drying and non-bleeding characteristics are designed to maintain stable long-term performance after installation.

The broad -50°C to +150°C continuous-use range, suitability for aluminium cooling surfaces and ability to work with CPUs, GPUs, air coolers and compatible liquid-cooling cold plates make MX-4 a versatile choice for gaming PCs, office computers, workstations and general computer servicing.

For users looking for an easy-to-apply, non-electrically-conductive 4g CPU and GPU thermal paste from ARCTIC, MX-4 remains a practical and well-established thermal-interface solution.