HP 6005 HP Enterprise/Mid-Market Desktop PC Power Supply Architecture - Page 5

Convertible Mini-Tower (CMT)/Micro-Tower (MT) The CMT and MT form factor power supplies have been based on the Intel ATX12V standard; however, these form factors stopped supporting the Intel ATX12V standard with the introduction of the dc7600 product family in 2005. Prior to the dc7600 product line, the HP tower chassis could support an ATX12V standard power supply with an adapter kit. With the introduction of the dc7600 line in 2005, the chassis could no longer support a standard ATX12V power supply. The Intel ATX12V standard power supply did not meet the product quality and reliability goals HP set for its business PC products. The ATX12V power dimensions constrain the integrated fan to 80mm. HP found the 80mm fan failed to meet thermal and acoustic performance requirements set for its business PC platforms, so the power supply dimensions were increased to allow a 92mm fan. This action effectively broke away from the ATX12V standard. The CMT and MT form factor power supply electrical interface prior to the introduction of the 2009 HP Compaq-branded business PC products did follow the ATX power supply electrical interface standard. There was no customer benefit to pursuing an alternate solution for this standard interface. In summary, the CMT and MT power supplies follow the industry standard electrical interface, but have not supported a mechanical industry standard for many product generations. Small Form Factor (SFF) The HP Small Form Factor (SFF) power supplies are based on the CFX12V industry standard form factor defined by the ATX specification. The exact CFX12V power supply dimensions, however, are not compatible with the traditional HP SFF system dimensions; therefore HP must deviate from the specification. The HP chassis design includes an innovative serviceability feature that requires additional deviation from the CFX12V specification. As with the CMT/MT, the CFX12V standard power supply did not meet the product quality and reliability goals for HP products. The CFX12V power dimensions constrain the integrated fan to 80mm. HP found the 80mm fan failed to meet thermal and acoustic performance requirements set for its business PC platforms, so the power supply dimensions were increased to allow a 92mm fan. This action effectively broke away from the ATX12V standard. The basic design of the CFX12V power supply form factor causes it to partially overhang the motherboard. This creates an additional height constraint on the motherboard components. In the HP SFF, the large 24-pin power connector must be placed in or near the motherboard region constrained by the overhanging power supply. There have been several solutions to this issue in recent products. The dc7700 and dc7800 SFF products used a smaller micro-fit connector instead of the larger, industry-standard, mini-fit connector. The dc7900 and dc5800 SFF products were able to return to the industry-standard mini-fit connector, but there were still challenges to that solution. When the dc7900 and dc5800 SFF returned to the industry-standard connector, the system still needed a fan control interface. This function had been integrated in 5