High density storage data center benefits, UltraSMR vs CMR, 34TB HDD efficiency, rack space savings storage
Executive Summary
High density storage enables more capacity within existing infrastructure constraints. Moving from 28TB CMR HDDs to 34TB UltraSMR HDDs increases capacity by approximately 21% within the same physical footprint, reducing device count, power draw, and cooling load while improving rack utilization and long-term scalability. While software changes are required to enable UltraSMR deployments, many organizations find the operational benefits worthwhile at scale.
Key takeaways
- High density storage reduces infrastructure overhead (racks, power, cooling)
- 34TB UltraSMR adoption delivers approximately 21% more capacity than 28TB CMR on a similar platform
- Lower drive count can simplify operations
- High density storage can defer facility expansion costs
Industry pressure: capacity growth without expansion
Due to infrastructure restraints, many organizations must seek to scale capacity without proportionally increasing rack footprint, power, or cooling. High density storage is a primary lever.
Why Bigger Drives Matter: 1PB–10PB Example
Moving from 28TB CMR hard drives to 34TB UltraSMR hard drives delivers approximately 21% more capacity within the same drive footprint, reducing drive count and the associated rack, power, and cooling requirements needed to reach a given capacity target.
Worked example
| Capacity Target | 28TB CMR Drives | 34TB UltraSMR Drives | Reduction |
| 1PB | 36 Drives | 30 Drives | -17% |
| 5PB | 179 Drives | 148 Drives | -17% |
| 10PB | 358 Drives | 295 Drives | -18% |
See full Ultrastar DC product lineup
Operational impact
Drive Reduction (~18%) translates directly into:
- Rack units saved: Fewer JBODs required -> fewer racks consumed
- Power reduction: 358 drives (28TB CMR) ~2,148W vs 295 drives (34TB UltraSMR) ~1,770W; ~378W saved per 10PB deployment
- Cooling load reduction: Every watt saved in IT load reduces cooling demand proportionally
- Floor space avoidance: Fewer racks -> can defer expansion or colocation costs
Industry pressure and technology evolution
The shift to higher-capacity storage is not driven by novelty, it is a direct response to infrastructure constraints. WD’s 28TB ^ Ultrastar HC5090 CMR and 34TB^ Ultrastar HC6100 UltraSMR drives illustrate this progression. Built on a similar 11-disk hardware platform, the HC6100 delivers approximately 21% more capacity in the same physical footprint through UltraSMR technology. While software and storage stack changes are required to fully enable UltraSMR deployments, the capacity advantage can make the transition compelling for organizations focused on maximizing storage density. At scale, moving from 358 drives to 295 drives at 10PB materially changes deployment planning.
The rack-space and cooling dividend
The operational impact of this density gain is immediate once enabled. Fewer drives are required to deliver the same capacity, which translates into fewer enclosures, fewer racks, and lower total power consumption. As power scales down, cooling demand follows. WD’s deployment strategy aligns with these priorities and enables customers to realize the benefits of 34TB UltraSMR high-density storage platforms while maintaining operational stability.
^ One terabyte (TB) = one trillion bytes. Actual user capacity may be less due to operating environment.
