Seagate Exos DC4U100

Overview

The Exos DC4U100 is the highest-density enclosure in Seagate's SCALE family, packing 100 drive bays into a single 4U, full-depth chassis. Alongside the EX4U74, it's built on the newer SAS-4 platform generation rather than the SAS-3 architecture behind the EX2U12, EX2U24 and EX5U84 — but where the EX4U74 is designed for standard-depth edge racks, the DC4U100 uses the full 1.2m chassis depth to maximise raw drive count and total capacity per enclosure.

It's designed specifically to pair with Seagate's Mozaic HAMR hard drives — filled with current 30TB-class Mozaic drives, a single enclosure can hold up to 3.2PB, making it one of the densest JBOD platforms available for large-scale, data-intensive deployments.

Key Specifications

Why Choose the DC4U100

The DC4U100 exists for one purpose: maximum density per rack unit. At 100 bays in a single 4U chassis, filled with Seagate's current Mozaic HAMR drives, a single enclosure can hold up to 3.2PB — a genuinely significant amount of capacity to fit in one rack position, which matters directly for data centre floor space and power/cooling budgets at scale.

It shares the same SAS-4 platform improvements as the EX4U74 — roughly double the throughput of the earlier SAS-3 SCALE enclosures, 30% lower power draw and 70% better cooling efficiency than legacy designs, toolless serviceability, and vibration mitigation engineering to protect performance and drive longevity across 100 closely packed drives. It's worth noting this is a hard disk (not flash) platform, so it's built for capacity-dense, high-throughput workloads rather than the lowest-latency, highest-IOPS tier of storage.

Because it uses the full chassis depth to fit the extra bays, the DC4U100 is the right choice specifically where you have the rack depth available and density is the priority — for standard-depth or edge deployments, the EX4U74 is the more practical fit.

Common Use Cases

• AI and ML training data pipelines — Large-scale training datasets and checkpointing where both capacity and ingest throughput matter.
• Hyperscale and cloud infrastructure — Maximising usable capacity per rack in space and power-constrained facilities.
• Long-term archive and observability data — Cost-effective, high-density retention for data that needs to stay accessible at scale.
• Sovereign and compliance-driven deployments — Built-in secure boot and air-gapped compliance for organisations with strict governance requirements.

Further Reading