ZM500-HP is ultra-quiet power supply complied with ATX12V Version 2.2, and supports the latest dual-core CPUs, as well as the latest dual graphic card systems (SLI). A heat pipe with ultra-high cooling performance incorporates the power suppliers with main rectifiers and enables high load operation even at low RPM for a dramatic reduction in noise levels.By implementing Active PFC (Power Factor Correction), the Power Factor (PF) is improved from 75% (Passive PFC) up to 99% while harmful harmonic frequencies are reduced to meet the line harmonic distortion requirements of IEC61000-3-2 Class D.This power supply is capable of reaching a maximum of 84% efficiency (230VAC, Full & Typical Load) through its use of high switching frequency and low power-loss circuitry.