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Power Supply: Cooler Master RS-850-EMBA

System Builder Marathon: High-Cost System
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Cooler Master’s top 850 W power supply has become a popular choice among boutique builders, and for good reasons : Efficiency up to 85% with .99% Active Power Factor Correction, a super-quiet 135 mm fan and a five-year warranty add to the allure of its stability.

With so many high quality models claiming similar specifications, what could make Cooler Master a clear winner ? Its longer-than-average CPU 12 V (8-pin and 4-pin) power leads were needed to reach the top corner of our motherboard, in a case that places its power supply bay at the bottom. We gave up our previously-chosen modular unit for this reason alone ; the competing model simply wouldn’t work.

850 watts is more than enough power, even after considering this marathon’s upcoming overclocking competition. Nevertheless, we may have chosen the company’s 1000 W unit had the 850 W part not already been on hand as a component of our New Reference System.

Cooling Fans : Scythe S-Flex, Antec SpotCool

Our Silverstone Temjin TJ09 case supported two fans in the top panel, but didn’t include them. Adding a radiator to that location would make these fans mandatory, but not just any fan would do. A high-end system is expected to provide a high-quality user experience, so we needed to balance noise against airflow. Scythe made this easy with its S-Flex SFF21E.

The SFF21E is the middle child of Scythe’s Fluid Dynamic Bearing equipped S-Flex family, and provides up to 49 CFM airflow at only 20.1 decibels. Because decibels are on logarithmic scale, two of these fans together only add up to around 23 dB. Airflow on the other hand is linear, and we expect around 90 CFM from the two 49 CFM fans when they’re in close proximity.

Hot chipsets and passive chipset cooling only work together with the help of a downdraft CPU cooler, which our system doesn’t have. That’s why the Striker II Formula includes two small radial fans to blow onto the VRM sinks of its heat-pipe assembly. Our experience with this type of supplemental cooling has shown that it’s barely adequate, and somewhat noisy. Instead, we chose to install Antec’s SpotCool universal fan, aiming it at the large Northbridge sink.

Designed like an 80 mm LED fan on a flexible stalk, an added benefit of the Antec SpotCool is its ability to cool surrounding components. By pointing ours towards the Northbridge sink, we were also able to keep our system’s RAM exceptionally cool.

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  • 0 Hide
    TDL , May 17, 2008 3:20 PM
    Thanks for the great article - I'm having fun building this - I do have 3 questions though - the fan duct assembly fan has 3 wire sets, 1 has the 3wire motherboard connector, the second taps into a regular power lead. The third is a single wire - the case documentation does not describe that one - what is that little single lead for? Also the motherboard sound card has some connectors on it - I assume one is for the case headphone/mic lead? Third, should teflon tape be used in the dual radiator threads if not how tight is tight enough for the O-rings? Thanks great article!
  • 0 Hide
    Dax3000 , June 25, 2008 5:20 AM
    Hi Thanks For The Great Article - I Am Also Building A System With A Few Modifications I Loved Asus Boards But Can Never Seem To Overclock Them At All So I Am Going With A EVGA 780i FTW when they come out, THat Processor IS Sweet But No Way CAn I JUstify PAying $1060 or more here in canada for 1 Pc Component when i already own three computers, I was thinking maybe a Q6850 when they come out, i have changed the middle fan in my case already and i am just waiting on my 120 rad to get here as i already have the other parts from another computer i built that i couldn't use so that saved me a few dollars:)  and i can't find that power supply anywhere so i am gonna do with a X3 1000 watt from ultra i hope it's good enough. and since i am not a really good overclocker no point in risking a high end system by messing around with 2 expensive graphics cards will 2 9800GTX+ work for me ? and omost importantly after my system is finished and filled how do i top it up if it needs more water do i have to take the top rad down to fill it everytime or can i just add water in to the same rad. thanks alot of your help and keep up the great work.
  • 0 Hide
    DaveCharleson , September 6, 2008 5:04 AM
    I've been installing and have three questions. First, there seems to be no pump in this system - have I just missed something?

    Second, the twin fan radiator seems to draw the air from inside the case up through the radiator and then out the top of the case. Wouldn't you want to draw cooler air from the outside past the radiator?

    Third, I don't see any connection to the video card although the 880GTX card is built for water cooling. Wouldn't you want to include this in the loop?

    This is my first build with water cooling so sorry if the questions belie this.
  • 0 Hide
    jimwalk , September 16, 2008 5:29 PM
    The Arctic Silver instructions for applying to Intel Quad Core CPU W/Heatspreader are at http://www.arcticsilver.com/pdf/appinstruct/as5/ins_as5_intel_quad_wcap.pdf