Summary

The 7Starlake 7SL-3500 is a 3U OpenVPX ATR chassis with an integrated, self-contained liquid cooling system compliant with the VITA 48.4 Liquid Flow-Through (LFT) standard. The key differentiator over earlier liquid-cooled ATR products is the closed-loop architecture: the coolant pump, heat exchanger, and reservoir are packaged within the chassis itself, eliminating dependence on external facility coolant or platform cooling infrastructure. The system supports up to 500 W total thermal design power in a platform that claims 10× greater thermal efficiency than air-cooled systems of comparable size.

Key Facts

  • Manufacturer: 7Starlake (Taiwan-based rugged compute company)
  • Product: 7SL-3500 series — variants include 7SL-3500-L2L (liquid-to-liquid) and 7SL-3500-L2A (liquid-to-air)
  • Form factor: 3U ATR chassis; 10.6" (H) × 7.6" (W) × 19.5" (D) including handles and connectors
  • Weight: Approximately 38 lbs without payload boards
  • Cooling standard: VITA 48.4 Liquid Flow-Through; self-contained closed-loop
  • Thermal capacity: Up to 500 W TDP (closed-loop, self-contained)
  • Power input: 18V–36V DC (MIL vehicle bus compatible)
  • Connectors: IP65-rated; MIL-STD D38999 connectors
  • Standards: OpenVPX, SOSA Technical Standard 3-slot backplane alignment; VITA 48.4 LFT
  • Applications: Software-defined radar, sensor fusion, EW, threat detection, UAS, hypersonic glide vehicles, ground-based autonomous systems

What It Is / How It Works

The 7SL-3500 addresses the gap between conduction-cooled systems (limited to ~150 W per chassis) and platform-coupled liquid-cooled systems (which require vehicle or aircraft plumbing infrastructure). By integrating the pump and heat exchanger within the ATR box itself, the 7SL-3500 enables high-density compute in any platform without special coolant plumbing.

Closed-Loop Liquid-to-Air Variant (7SL-3500-L2A) Liquid circulates internally across the VPX module cold plates (via VITA 48.4 integral heatsinks), collects heat, and routes it to an internal liquid-to-air heat exchanger. The heat exchanger fans exhaust heat to the ambient environment. Net result: the chassis is an air-cooled box from the platform’s perspective, but liquid-cooled internally. The liquid-to-air configuration is suitable for deployments with ambient cooling access (vehicle exterior air, aircraft ducted air).

Platform-Coupled Liquid-to-Liquid Variant (7SL-3500-L2L) For platforms with access to a coolant loop (shipboard chilled water, vehicle engine cooling circuit), the 7SL-3500-L2L connects its internal cooling manifold to the platform supply. This enables sustained high-TDP operation beyond what an internal heat exchanger can handle, leveraging the platform’s larger cooling capacity.

VPX Slot Configuration The 7SL-3500 incorporates:

  • 3-slot VPX backplane aligned with SOSA Technical Standard profiles
  • Intel i7-1185GRE or Core Ultra 7-155H host processor
  • IP65 sealed chassis for dust and splash protection
  • MIL-STD D38999 connectors (military-grade circular connectors for shock/vibration resistance)

Thermal Efficiency Claim 7Starlake claims 10× greater thermal efficiency than “conventional air-cooled systems of similar size.” This figure likely reflects the liquid-to-module heat transfer coefficient advantage over surface air convection, but the specific test conditions and reference system are not published.

Notable Developments

  • 2025: 7Starlake unveiled the next-generation 7SL-3500 at a press event; Military Embedded Systems covered the liquid-cooled 3U VPX ATR introduction
  • 2024: 7SL-3500-L2L (liquid-to-liquid variant) entered product catalog with 500 W TDP spec
  • Prior: 7Starlake’s earlier THOR200-U8-D (half-rack NAS for submarine/aerospace) established the company’s presence in US defense markets before the VPX ATR product line expansion

Claim Verification

Claim: “Up to 500 W TDP in self-contained closed-loop chassis”

Status: Partially verified

Supporting sources:

Refuting / questioning sources:

  • No independent lab test report confirming 500 W sustained operation at ambient temperature limits (-40°C or +60°C) has been located. The 500 W figure likely represents the cooling system capacity, not a validated sustained processor TDP at worst-case thermal conditions.

Summary: 500 W TDP is a plausible specification for VITA 48.4 LFT systems; the figure is cited by a third-party publication but not independently measured.

Claim: “10× greater thermal efficiency than air-cooled systems of similar size”

Status: Unverified

Supporting sources:

Refuting / questioning sources:

  • Reference system and test conditions not specified. The 10× figure is company-issued with no methodology disclosed.

Summary: Plausible directionally (liquid cooling substantially outperforms air for high-power-density components) but the specific multiplier is unverified.

Key People

People — Last Reviewed: 2026-04-25

Sources