HPE ProLiant Compute XD685 (HGX B300) vs QCT QuantaGrid D75L-3U
Both are built on the NVIDIA HGX B300 8-GPU baseboard, so their accelerator performance is identical rather than merely similar. The choice between them is chassis, cooling, expansion and supplier, not FLOPS.
What actually differs
| Specification | HPE ProLiant Compute XD685 (HGX B300) | QCT QuantaGrid D75L-3U |
|---|---|---|
| Vendor | HPE | QCT |
| Part number | S6Y07A | D75L-3U |
| Form factor | rack | rack |
| Released | 2025 | — |
| Accelerator | 8x B300 | 8x B300 |
| Aggregate memory | 2.1 TB | 2.3 TB |
| Aggregate bandwidth | 64.0 TB/s | — |
| System power | — | — |
| Interconnect | NVLink 5.0 / NVSwitch 4.0 across the HGX B300 baseboard; 4x FHHL PCIe Gen5 x16 slots for fabric, NIC or DPU | One NVIDIA HGX B300 8-GPU baseboard with fifth-generation NVLink at 1.8 TB/s; eight onboard ConnectX-8 SuperNICs at up to 800Gb/s for east-west traffic, with up to three further NICs for north-south |
Rows shown in grey are identical between the two.
HPE ProLiant Compute XD685 (HGX B300)
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.
Vendor product pageQCT QuantaGrid D75L-3U
QCT's density play: the same NVIDIA HGX B300 8-GPU baseboard as its 10U sibling, compressed into 3U by liquid cooling and designed for the NVIDIA MGX rack rather than a standalone chassis. It takes power from a 1400A busbar and rack power shelves instead of its own supplies, which is why no power figure appears here at all, and supports DC-SCM. Fifth-generation NVLink runs at 1.8 TB/s, and eight onboard ConnectX-8 SuperNICs handle east-west traffic at up to 800Gb/s. Hosting is two Intel Xeon 6700 P-core processors at up to 350 W. QCT states 2.3 TB of HBM3e per system, which is eight B300 modules at 288 GB apiece; note NVIDIA quotes 2.1 TB for the same baseboard, and this entry keeps QCT's figure since QCT is the one publishing it. No throughput figure is given for this model.
Vendor product page