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Flopper.io System Specification Sheet

HPE ProLiant Compute XD685 (HGX B300)

8x B300 Blackwell Ultra rack 2025

Overview

36.0
FP8 PFLOPS Dense
2.1 TB
Aggregate Memory
64.0 TB/s
Aggregate Bandwidth
Aggregate Power

Performance Metrics

PrecisionPeak (PFLOPS)Per GPU (TFLOPS)TFLOPS/W
FP640.01.3
FP320.675.0
TF329.01125.0
FP1618.02250.0
BF1618.02250.0
FP836.04500.0
FP4108.013500.0
FP636.04500.0

All figures are dense. Vendors commonly headline the sparse number, which is twice the dense one.

Configuration

Accelerator
B300 SXM 288GB
Count
8
Memory per GPU
288 GB
Bandwidth per GPU
8.0 TB/s

Power & Efficiency

Aggregate Power
TDP per GPU
1400 W
FP8 Efficiency
Aggregate Bandwidth
64.0 TB/s

System Details

Vendor: HPE
Family: ProLiant Compute XD
Architecture: Blackwell Ultra
Form Factor: rack
Release Year: 2025
Process Node: 4nm

Interconnect

NVLink 5.0 / NVSwitch 4.0 across the HGX B300 baseboard; 4x FHHL PCIe Gen5 x16 slots for fabric, NIC or DPU

Notes

The eight-way XD685 in its NVIDIA HGX B300 configuration, which requires the high-power liquid-cooled chassis S6Y07A rather than the standard DLC one. This is the denser sibling of the air-cooled XD690, which reaches the same eight Blackwell Ultra GPUs in 10U where this does it in 5U. Two fifth-generation AMD EPYC processors, 24 DIMM slots and up to 6 TB of DDR5-6400, eight EDSFF NVMe E3.S drives. HPE publishes no system power draw for the XD685, only twelve 3,000 W Titanium supplies with ten deployable, so unlike the XD690 no figure is recorded; the compute shown is NVIDIA's specification for the HGX B300 baseboard rather than an HPE claim.