RM-4U8G
SKU: LMT-RM-4U8G-LPA barebone AI server platform: eight full-height PCIe Gen 5 GPU slots in a 4U chassis, engineered around a closed liquid cooling loop with an in-chassis radiator, so it deploys in a standard server room without facility plumbing or an external CDU. Platform-level power, no motherboard lock-in. Cooling designed by the EK engineering team; engineered and assembled in Komenda, Slovenia.
A barebone platform: LM TEK supplies the chassis, the integrated cooling loop, and platform-level power. You specify the board, CPUs, GPUs, memory, and storage.
- Chassis
- 4U · 19" standard rack
- GPU slots
- 8 · full-height PCIe
- Cooling
- Integrated liquid · in-chassis
- Max chassis power
- Up to 8000 W sustained
- CPU sockets
- AMD SP5, Intel LGA 4677 / LGA 4710 / LGA 4710-2
A barebone server platform engineered as a single thermal and power system
RM-4U8G is the result of asking what an 8-GPU AI server should look like if you started over. The chassis is engineered around a closed liquid cooling loop with an in-chassis radiator. Power distribution is platform-level, separated from the motherboard's VRM. The PCIe slot layout is built around the cooling loop's physical envelope, not retrofitted around a board form factor.
What the platform does not do is force you onto a proprietary motherboard. The board, the CPUs, the memory, the storage, the network adapters: all off-the-shelf enterprise parts, sourced and refreshed independently of the chassis. The reason customers buy RM-4U8G is the cooling and the chassis discipline; the reason customers stay with RM-4U8G is that nothing else about the build is locked to one supplier.
Engineered and assembled in Komenda, Slovenia. Cooling system designed by the EK engineering team, twenty-five years deep in high-performance liquid cooling. Pressure envelope, materials, and operating range are documented at the supplier level and do not differ from the rest of the LM TEK liquid-cooling catalogue.
Six things that matter.
4U envelope
Eight full-height GPU slots in a four-rack-unit chassis. Density that normally needs 6U or 8U.
Eight GPU slots
Full-height PCIe slots, each provisioned for liquid-cooled GPU water blocks at the platform's power envelope.
Integrated liquid cooling
Closed loop, in-chassis radiator, no external CDU. Deploys in standard server rooms without facility plumbing.
No motherboard lock-in
Standard EATX and EEB server boards from your vendor of choice. CPU, RAM, NVMe, NICs are all off-the-shelf.
EK-engineered cooling
Materials discipline, pressure envelope, and manifold geometry from the EK liquid-cooling reference, transferred to enterprise rack scale.
Platform model
Barebone chassis with integrated cooling, power, and platform support. GPUs and internals specified per deployment.
Three design decisions worth calling out.
E-ATX-compatible · 4U · 19" rack
The chassis is engineered around standard EATX server motherboards rather than a proprietary board. PCIe slot positions and clearance accommodate the cooling loop without needing custom riser cards. Mounting hardware is rack-standard. The platform takes ordinary enterprise components and arranges them at extraordinary density.
Closed integrated liquid loop · in-chassis radiator
Pump, manifold, GPU and CPU water blocks, radiator, and reservoir are all inside the chassis. The radiator faces the front intake; airflow paths are engineered alongside the loop, not as an afterthought. Working pressure 2500 Pa; maximum pressure 30 000 Pa with EK-Pro PRM, 75 000 Pa otherwise. Materials stack: nickel-plated copper, stainless steel, POM Acetal, EPDM seals.
Redundant high-density PDU · platform-level distribution
Power distribution is engineered at the platform level so the GPU power budget does not depend on the motherboard's VRM. Redundant PSUs, hot-swap modules, and headroom for the full 8-GPU configuration at maximum sustained load. The customer's motherboard chooses CPU and memory; the platform chooses how power reaches the GPUs.
Proof and deployment
The honest envelope
- · Deploys in standard server-room conditions: 5 to 35°C ambient, 5 to 60°C coolant.
- · No facility plumbing. No external CDU.
- · Five redundant 2000 W 80 PLUS Titanium PSUs, up to 8000 W sustained.
- · You still provision rack power and rack cooling headroom.
Plan for the heat
A dense GPU server converts nearly all of its electrical draw into heat in the room. In extended thermal torture testing, a fully populated RM-4U8G measured 6800 to 7000 W sustained draw. That heat load is defined by the GPUs and CPUs in the configuration, the same as any other max-spec 8-GPU server. Without added room cooling, ambient will rise under sustained load. The RM-4U8G’s operating envelope extends to 35°C ambient, so a room that warms under load stays inside specification, but scope rack cooling for the configured load before deployment.
In LM TEK torture testing at 30°C ambient, GPU package temperatures held at 76 to 81°C, inside the envelope a real server room can offer.
Acoustic measurements under sustained load are available on request.
Efficiency, and the water question
Power conversion uses 80 PLUS Titanium supplies, the highest rating in the certification; at multi-kilowatt sustained draw, conversion losses are a real operating cost and an increasingly common bid and tender criterion. And the water objection to AI infrastructure does not apply here: the loop is closed, filled once at assembly with engineered coolant, and consumes no water in operation. There is no facility water connection to consume from.
From starter footprint to production maximum.
Reference configurations are examples drawn from real customer builds, not a fixed bill of materials. The final BOM is specified per deployment; LM TEK engineering validates compatibility and cooling capacity for the chosen GPU before quote.
| Tier | GPU | CPU | RAM | Storage | Use case |
|---|---|---|---|---|---|
| Modest start | 2× NVIDIA RTX 6000 Ada | 1× AMD EPYC 9354 (32-core) | 256 GB DDR5 ECC | 2× 3.84 TB NVMe | Workstation crossover · departmental AI · single-team inference |
| Mid-tier | 4× NVIDIA RTX A6000 | 2× AMD EPYC 9474F (48-core) | 512 GB DDR5 ECC | 4× 3.84 TB NVMe | Lab / research group · multi-user inference · light fine-tuning |
| Production maximum | 8× NVIDIA H200 NVL | 2× Intel Xeon Platinum 8580 | 1 TB DDR5 ECC | 8× 7.68 TB NVMe | Enterprise inference · production fine-tuning · multi-tenant |
Everything in the loop, from the same catalogue.
The cooling loop inside RM-4U8G is built from the same components that ship into LM TEK workstation deployments. Same materials discipline, same pressure envelope, same supplier.
Browse the full catalogue →Full datasheet
| Form factor | 4U · 19" rack chassis |
| Dimensions (L × W × H) | 760 × 482 × 178 mm |
| Net mass (barebone) | 38 kg · approximate |
| GPU slots | 8 × full-height PCIe Gen 5 |
| GPU power envelope | Up to 700 W per slot · sustained |
| CPU sockets supported | AMD SP5 · Intel LGA 4677 · Intel LGA 4710 · Intel LGA 4710-2 · per chosen motherboard |
| Motherboard form factors | EATX · EEB · server reference |
| Memory slots | Per chosen motherboard · typically 24 × DDR5 RDIMM |
| Storage bays | 8 × NVMe U.2 · hot-swap · front access |
| Networking | Per chosen motherboard · OCP 3.0 mezzanine supported |
| Cooling type | Integrated liquid · in-chassis closed loop · in-chassis radiator · no external CDU |
| Coolant materials stack | Nickel-plated copper · stainless steel · POM Acetal · EPDM seals |
| Working pressure | 2 500 Pa |
| Max pressure | 30 000 Pa (with EK-Pro PRM) · 75 000 Pa (otherwise) |
| Operating temperature range | 5 – 35 °C ambient · 5 – 60 °C coolant |
| Power supply | 5 × 2000 W · 80 PLUS Titanium · hot-swap · redundant |
| Power distribution | Platform-level PDU · independent of motherboard VRM |
| Country of origin | Slovenia |
All figures measured at supplier level. Third-party independent measurement reports are available on request under NDA.
Compatibility
Motherboards: EATX, EEB, and server reference boards from major vendors. Workstation boards in the same envelope are also supported but not the primary use case.
CPU sockets: AMD SP5 (EPYC 9004 / 9005), Intel LGA 4677 (Xeon Scalable 4th / 5th gen) and Intel LGA 4710/Intel LGA 4710-2 verified. Other server sockets supported via available motherboard choices.
GPUs: Full-height PCIe Gen 5, up to 700 W per slot sustained, water-block-equipped. Verified with the GPU water-block catalogue (RTX 6000 Ada, RTX A6000, H100 NVL, H200 NVL, A100, RTX PRO 6000 Blackwell, others on request).
Networking: OCP 3.0 mezzanine and standard PCIe NICs supported.
Shipped contents
- · Chassis with rack rails and front bezel
- · Integrated cooling loop · pre-filled, pre-tested with EK-CryoFuel coolant
- · Redundant power supply assembly · 5 × 2000 W · 80 PLUS Titanium · hot-swap
- · Platform-level power distribution unit
- · GPU and CPU water blocks per chosen configuration (separately specified)
- · Mounting hardware kit and integration manual
- · Quick-disconnect couplings for serviceability
- · Not included: motherboard, CPUs, GPUs, RAM, storage, network adapters; sourced separately per the configuration BOM
- · No proprietary components; every internal part has a second source.
- · Board and silicon are sourced and refreshed independently of the chassis.
- · One platform carries a build from two GPUs to eight 700 W GPUs, so the entry configuration and the end state are the same asset.
- · Titanium-rated power conversion and zero operational water use are scoreable criteria in energy-weighted tenders.
A full Procurement and Total Cost of Ownership brief is available on request.
Specified per deployment, validated before quote.
Send LM TEK engineering your intended board, CPUs, GPUs, memory, and storage. Engineering confirms compatibility, validates cooling capacity for the chosen GPU, and produces an integration spec before any quote.
- The RM-4U8G is a barebone server platform. The motherboard, CPUs, GPUs, memory, storage, and network adapters are not included and are sourced separately per the configuration bill of materials. Reference configurations are examples drawn from real customer builds and do not constitute a fixed specification.
- Component compatibility is verified by LM TEK engineering against the buyer’s chosen board, CPUs, and GPUs before quote. Compatibility lists are current at time of publication and subject to change. Contact LM TEK engineering to confirm compatibility for your configuration before purchase.
- Cooling capacity is validated per deployment for the selected GPU. The 700 W per-slot sustained envelope and the 8000 W sustained chassis figure are platform maxima; achievable sustained power depends on the chosen components and ambient conditions.
- The integrated loop is pre-filled with EK-CryoFuel. Use only engineered coolant specified by LM TEK. Use of incompatible or untreated coolant may damage the loop and void warranty.
- Operating envelope: 5–35°C ambient, 5–60°C coolant. Working pressure 2500 Pa; maximum pressure 30 000 Pa with EK-Pro PRM, 75 000 Pa otherwise. Operation outside these limits is not supported.
- All figures are measured at supplier level. Third-party independent measurement reports are available on request under NDA.
- Engineered and assembled in Slovenia (Komenda). Cooling system designed by the EK engineering team.
- Dimensional and technical drawings are copyrighted material of LM TEK and are provided for rack-integration planning only.