P91-10k vs APC Smart-UPS SRT8KRMXLT
The Xtreme Power P91-10k and APC Smart-UPS SRT8KRMXLT are online double-conversion rackmount UPS for enterprise servers, network, and telecom infrastructure, both on VRLA batteries. The P91-10k provides higher usable output (10 kW vs 8 kW) in a smaller 4U footprint with TAA compliance; the SRT8KRMXLT emphasizes a larger integrated battery for longer runtime at its 8 kW rating.
What the P91-10k brings
- Higher usable watt capacity (10 kW vs 8 kW)
- Smaller rack footprint (4U vs 6U) for high-density racks
- Flexible rack or tower deployment
- Longer battery warranty (3 vs 2 years)
- TAA compliance for federal procurement
Side-by-side specifications
| Specification | Xtreme Power P91-10k | APC Smart-UPS SRT8KRMXLT | Advantage |
|---|---|---|---|
| Capacity | 10 kVA / 10 kW | 8 kVA / 8 kW | P91 – higher usable capacity (10 vs 8 kW) |
| Topology | Online double conversion | Online double conversion | Equivalent protection |
| Runtime (8 kW load) | 4 min | 5 min | APC – longer runtime at 8 kW |
| Battery technology | Sealed lead-acid (VRLA) | Sealed lead-acid (VRLA) | Comparable architecture |
| External battery packs | Yes | Yes | Runtime expansion on both |
| Rack height | 4U (2U UPS + 2U battery) | 6U | P91 – smaller footprint (4U vs 6U) |
| Form factor | Rack / tower | Rack / tower | Flexible deployment |
| Input / output voltage | 208 / 220 / 230 / 240 V | 208 / 220 / 230 / 240 V | Comparable |
| Warranty | 3 yr UPS / 3 yr battery | 3 yr UPS / 2 yr battery | P91 – longer battery coverage |
| Compliance | UL1778, CE, FCC, RoHS, TAA | UL1778, IEC 62040-2, RoHS | P91 – TAA compliant |
Specifications based on publicly available manufacturer data; confirm against current vendor documentation. Runtime shown at the SRT8K’s 8 kW rating.
Choosing between them
The P91-10k leads on usable capacity, rack footprint, battery warranty, and TAA; the SRT8KRMXLT offers a larger integrated battery and longer runtime at its 8 kW rating.
Choose the P91-10k if you need
- Higher usable output (10 kW vs 8 kW)
- A smaller 4U rack footprint for high-density racks
- Flexible rack or tower deployment
- Longer battery warranty and lower lifecycle risk
- TAA compliance for federal procurement
The SRT8KRMXLT may fit if you need
- Longer runtime at 8 kW from a larger integrated battery
- Alignment with an existing APC Smart-UPS Online standard
- A non-regulated deployment
Frequently asked questions
Engineers evaluating the SRT8KRMXLT often look for higher output or better rack efficiency. The Xtreme Power P91-10k is commonly evaluated as an alternative, delivering 10 kW of usable output in a 4U footprint with TAA compliance.
Modern IT equipment operates near unity power factor, so usable watt capacity, not the VA rating, determines how much equipment a UPS can actually support.
At the SRT8K’s 8 kW rating its larger integrated battery runs slightly longer, about 5 minutes vs 4 minutes for the P91-10k. Both accept external battery packs, and the P91-10k delivers a higher 10 kW peak capacity.
Yes. The P91-10k is UL1778 listed and TAA compliant for U.S. federal and public-sector procurement; the SRT8KRMXLT is not TAA listed.
Related comparisons
Specifying a rackmount online UPS?
Xtreme Power supports specification, runtime sizing, and lifecycle planning for enterprise servers, network core, telecom, healthcare, and education racks.