News
June 18, 2026
As AI/ML clusters push server rack power density beyond 20 kW per rack, the server power supply has evolved from a commodity component into a software-defined, digitally-managed subsystem. The APEX 2000W Titanium PSU is built for this new reality — delivering 96% peak efficiency with a feature set that includes PMBus 1.2 telemetry, cold redundancy, in-system firmware updates, and persistent black box fault recording. Here's what's under the hood.
At 2000W per PSU and four PSUs per rack in a 3+1 redundant configuration, total rack power draw is 6000W. The difference between 80Plus Gold (87% at 50% load) and Titanium (96% at 50% load) at this scale is 540W of waste heat per rack — heat that must be removed by the data center cooling system. Over a 100-rack deployment, Titanium saves 54 kW of cooling load and an estimated $47,000 per year in energy costs at $0.10/kWh.
| Load | Titanium Min Efficiency | Gold Min Efficiency | Waste Heat Difference @ 2000W |
|---|---|---|---|
| 10% (200W) | 90% | — | — |
| 20% (400W) | 94% | 87% | 25W saved |
| 50% (1000W) | 96% | 90% | 67W saved |
| 100% (2000W) | 91% | 87% | 80W saved |
The APEX 2000W implements the full PMBus 1.2 command set with PEC (Packet Error Checking) per SMBus 2.0. The BMC can read real-time telemetry from every PSU in the rack:
The SMBAlert# signal is asserted within 3 ms of an AC input loss — fast enough for the system BMC to trigger a controlled workload migration before hold-up capacitors deplete. Default masking exposes UV fault, OC warning, and OT warning events with configurable per-event masking via SMBALERT_MASK.
In a traditional N+1 configuration, all PSUs run continuously regardless of load — wasting energy at light loads where efficiency drops. Cold Redundancy 2 uses a dedicated CR_BUS signal between PSUs to dynamically power-cycle redundant units based on actual system load.
How it works: One PSU is designated Master (always ON). Slave PSUs enter Cold Standby when system load is below a configurable threshold. CR_BUS is asserted (pulled low) when any active PSU faults or output voltage falls below the Vfault threshold — waking standby PSUs within 100 μs to maintain output regulation without dropping the bus.
The system can configure up to four PSUs with distinct Von/Voff thresholds per slot position, optimizing the efficiency curve for each configuration (1+1, 2+2, 3+1). In a four-PSU rack running at 30% load, cold redundancy can reduce PSU energy consumption by 15–20%.
One of the most operationally significant features: the APEX 2000W supports full firmware updates while the PSU is powered ON and delivering load. The dual-bank architecture separates the boot loader (immutable, never updated by the system) from the main program (field-updatable via PMBus).
The update flow: MFR_FWUPLOAD_MODE → PSU enters upload mode. Fan runs at fixed high speed to maintain cooling. PWOK and PSON# continue functioning normally. MFR_FWUPLOAD → Blocks of the new FW image are sent with sequencing numbers. The PSU assembles them into the correct memory space. MFR_FWUPLOAD_STATUS → BMC verifies: image received, image valid, HW compatible, FW revision.
If the uploaded image is corrupt, the PSU boots into loader mode with minimal operating capability and re-enters upload mode — no bricked PSUs, no truck roll. The BMC maintains a backup of the last-known-good image.
When a critical fault triggers PSU shutdown (OV, OC, UV, OT, fan failure, AC loss), the black box saves a complete snapshot to non-volatile memory:
Data is accessible via PMBus by applying 12V standby power alone — no AC input required. This means a failed PSU can be interrogated on the bench without powering the full system.
| Parameter | Value |
|---|---|
| Max Output Power | 2000W |
| Form Factor | 1U, hot-pluggable |
| Efficiency | 80Plus Titanium (96% @ 50% load) |
| Input Voltage | 90–264 VAC / 180–320 VDC |
| Power Factor | >0.99 @ 100% load, 230 VAC |
| Main Output | +12 V / 166 A |
| Standby Output | +12 Vsb / 3 A |
| Hold-up Time | ≥11 ms @ 70% load |
| Digital Interface | PMBus 1.2, SMBAlert#, PEC |
| Redundancy | N+1 (max 3+1), Cold Redundancy 2 |
| FW Update | In-system, dual-bank, bad-image recovery |
| Diagnostics | Black box fault recording, FRU EEPROM |
For pricing, samples, and full technical documentation, contact the APEX team via [email protected] or WhatsApp.
