Update - now available as D5 PWM Version from Swiftech:
In response to the overwhelming demand and popularity of the MCP655 Series FrozenCPU.com has worked with Swiftech to bring you a more versatile version. Want your pump to run as quiet as possible? Now you can have that as well as the available power of the MCP655 in the all new MCP655-PWM. That is right, a PWM version on the MCP655!!
The MCP655 pump is a high reliability, high pressure industrial pump, featuring a 50,000 hour MTBF (5 year lifetime). Such reliability is afforded by the unique design of this pump, which contains only one moving part: the magnetically driven spherical impeller spins on a single ceramic bearing, thus extending the life of this pump beyond existing standards.
The pump is completely plug-and-play, and connects directly to any computer power-supply through standard 4 pin power connectors and a PWM 4-Pin header. It's compact design, quiet and powerful motor make it ideally suited for heavy duty cooling in environments where space is at a premium.
50,000 hours MTBF (Mean Time Between Failure) equivalent to 5 years lifetime
Superior 12 Volts DC convenience: plugs into the computer power supply
The MCP655-PWM can be used with full confidence in any MP servers, and high-end workstations
Superior real world performance versus any aquarium pump we have tested to this date
The high pressure capability of the MCP655-PWM is particularly well adapted to high-flow systems using 1/2" ID or 3/8" ID Tubing
Compact Design
No maintenance when used with de-mineralized water, and anti-fungal additives (Swiftech HydrX additive is recommended)
Nominal voltage: 12 V DC
Operating voltage range: 8 to 24 VDC
Nominal power (@ 12 V): 37 W Max
Nominal current (@ 12 V): 2 amps
Motor type: Brushless, microprocessor controlled
Maximum head: 13 ft (4 m)
Maximum discharge: ~ 317 GPH (1200 LPH)
Performance will vary based on housing used


http://www.xtremesystems.org/forums/...Pump-Reservoir