6 flagship GPUs in one 4U server: custom liquid cooling as a response to physical limitations
Client: LANGARDEN PROJECTS LLC
Challenge: Overcoming physical limitations of rack mounting
1. Challenge: Overcoming Physical Limitations
Install 6 RTX 4090/5090 level cards in a 4U chassis.
Standard cards occupy 3-4 slots, physically a maximum of 2-3 fit in the server.
- Problem: Physical limitations of rack mounting do not allow installing the required number of flagship GPUs.
- Risk: Inability to achieve the required computing power in a compact 4U format.
- Task: Create a solution that cannot be bought "off the shelf" — place 6 flagship GPUs in a 4U chassis without performance loss.
2. Solution: Transformation and Hydrodynamics
We created a solution that cannot be bought "off the shelf". The key to success is a custom liquid cooling loop (Custom Loop).
1. GPU Transformation
We removed the standard air coolers and installed full-coverage water blocks (Full-Cover).
- Result: The card transformed from a "thick" 4-slot brick into an elegant 1-slot module.
- Effect: This allowed placing 6 GPUs in a row, overcoming the physical limitations of the standard rack format.
Graphics Cluster: 6x GeForce RTX 4090/5090 (Watercooled)
The foundation of computing power — six flagship NVIDIA graphics cards with custom liquid cooling.
- Transformation: Removal of standard air coolers and installation of full-coverage water blocks (Full-Cover).
- Result: The card transformed from a "thick" 4-slot brick into an elegant 1-slot module.
- Effect: Placement of 6 GPUs in a row in a 4U chassis, stable frequencies at 100% load, no thermal throttling.
Core: Threadripper PRO 7995WX
The 96-core processor provides 128 PCIe lanes.
- Critical importance: This is critically important so that each of the 6 graphics cards operates at full bus speed without a "bottleneck".
- Performance: Maximum bandwidth for all GPUs simultaneously.
Power Supply: Dual 4.1 kW Configuration
The dual PSU configuration ensures stability during peak consumption spikes typical of powerful GPUs.
- Innovation: Two power supply units installed with a total capacity of 4100W.
- Result: Stable operation of all components at maximum load without voltage drops.
Implementation Result:
The server operates without throttling under 100% load — a result unattainable with air cooling. This demonstrates our engineering excellence in the High-End HPC segment.
Configuration
- Graphics Cards:6x NVIDIA GeForce RTX 4090/5090 Watercooled
- Processors:AMD Threadripper PRO 7995WX [96 cores]
- Cooling:Custom Loop Liquid Cooling (Full Cover Blocks)
- Power Supply:2x PSU [Total: 4100W]
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