Pump Top Testing

With the pump itself isolated and tested, it is now time to see how the Swiftech MCP655 top itself performs. To do so, I used the same pump on various Laing D5 tops from various companies - some standalone, some integrated into reservoirs. The testing methodology to generate a P-Q curve was the same as before, though only with a 100% PWM duty cycle this time around.


There is a fair amount of variation from top to top, with some focusing on providing a higher max head at the expense of flow rate and others going the other way round. A good balance of the two ends up being the best overall in realistic scenarios, and here, the Swiftech MCP655 top does not disappoint with excellent overall performance. Swiftech has had a history of high-performance tops for a while now, sometimes at the expense of aesthetics even, and it is refreshing to see them carry on with their high performance metrics with an updated acrylic/acetal top to meet end user demands.

A Realistic Loop Test

So far, we have seen the results for extremely controlled tests, often to minimize the effects of involved variables. However, this does result in an incomplete picture by focusing on maximum possible values as opposed to realistically achieved values. Take a pump's P-Q curve, for instance. The Laing D5 is rated at 1500 LPH (liters per hour, 6.6 GPM) of max flow, which is great to look at but corresponds to an open loop with no liquid-flow restriction. Close the loop and it is reduces to ~4.1-4.2 GPM. Add in your everyday closed loop components and you are looking at a max flow rate of ~1-1.2 GPM for most people. This is where the budget pumps come in and why you should consider all options.

I used an XSPC Raystorm Pro CPU block, a Swiftech Komodo R9-LE GPU block, a Black Ice Nemesis GTS 360 radiator, and two sets of Koolance QD3 quick disconnects to go with six Bitspower 1/2" x 3/4" fittings and Primochill Advanced LRT tubing in the same size. The blocks are one of the least restrictive in each category, and the addition of the QDCs and relatively more restrictive radiator brings the average restriction close to what most loops would have. I have tested the aforementioned pumps, including the Swiftech MCP35X and MCP50X which make a comeback here. At the same time, I measured pump noise alone by placing the setup inside an anechoic chamber at 19 dBA, with a sound probe 6" away from the pump. No other sound source was inside the chamber at the time these measurements were taken.


Things get a lot closer here, and the MCP655 does a very good job at keeping things flowing at a low noise level. It is bested by the new Alphacool VPP755 at the higher end and from a noise perspective, but the Alphacool VPP755 does not have the proven long-term reliability the Laing D5 enjoys yet. There are a few more budget pumps that do a decent job from a performance/noise basis, but those wanting the best-possible performance at reasonable noise levels will look at the Laing D5, which makes the Swiftech MCP655 a strong option.

Given the nature of so many moving parts inside a pump, reliability is hard to talk about within a review's time frame. It is thus helpful that the Laing D5 and DDC have both been in use for years in some of my systems and that of others. The D5 especially has lasted through the test of time, and this is another plus for the Swiftech MCP655. Since there are so many hard-to-quantify variables when it comes to a pump, I will refrain from making an attempt at a relative performance chart and, as such, a price-to-performance chart as well.