Watercooling Motherboard Voltage Regulators

Like it says – Nick Poirier

The other day I started to cut up a big heatsink to get small heatsinks for the six CPU voltage regulators on my NF7-S (rev 2.0) motherboard. As I was cutting up the heatsink I said to myself, “It must be possible to water cool these instead!” So over the next day or two, while at work, I conjured up a design in my head. And now that design has been built 🙂

These pictures show the intended target: the six CPU voltage regulators (VRs):

Mobo2
  • Without any cooling these guys get incredibly hot (I measured them at 65’C!!)
  • Those round donut shaped components got even hotter

    Mobo1
  • Even those four big capacitors got real toasty

    Mobo3

    This is the VR water block I made:

    WB
  • The base of the block is a piece of 1″ wide copper flat-bar (1/8″ thick)
  • It was cut (moulded) to fit around those four big capacitors located between the VRs
  • The water chamber is made of a piece of standard 1/2″ copper pipe cut in half lengthwise
  • Small pieces of the copper flat-bar were used to “cap” the open ends
  • Holes were drilled into the top for the 3/8″ OD (1/4″ ID) inlet and outlet pipes
  • The inlet/outlet pipes were rounded on the end to conform to the inside of the water chamber
  • The base of the block has many starter-holes drilled into it (on the inside where the water flows)
  • These holes do not go all the way through of course
  • The holes were made to disrupt the water flow and to increase heat transfer
  • I realize I could have spent more time removing excess solder and cleaning up the block 🙂

    These pictures show the hose I am going to use with the block:

    Hose
  • The hose is very “rubbery”, extremely flexible, and has dimensions of 3/8″ OD (1/4″ ID)

    Mobo

  • Once pushed over the 3/8″ OD pipes it does NOT want to come off (ie no need for hose clamps)
    {mospagebreak}

    Nick Poirier

    Some pictures at different angles of the block placed on the VRs:

    On Mobo1
  • It’s a tight fit for sure, but the block drops in easily

    On Mobo2
  • The six VRs below all contact the underside of the block (thanks Abit for making them the all same height!)
  • Those four big capacitors on one side are not squeezed at all by the block

    On Mobo3
  • Those three donut shaped components on the other side are not in contact with the block either

    On Mobo4
  • You can also see my lapped nForce2 Ultra 400 northbridge chip in some of these pictures

    This picture shows the actual installation of the block:

    Install
  • Arctic Alumina thermal epoxy was used to secure the block in place
  • A “C” clamp was used to apply pressure
  • A mouse pad was placed under the motherboard to prevent it from flexing due to the uneven solder points on the underside
    {mospagebreak}

    Nick Poirier

    These pictures show the block fully installed in its final working state:

    Installed1
  • I drilled a 3/8″ hole into my 1″ flow splitter from my Laguna pump
  • The exiting coolant from the VR block simply dumps back into my reservoir below

    Installed2
  • That is not the best way to handle the heated coolant, but for right now it is sufficient

    Installed3
  • I expect this block will help reduce my CPU temperature as well due to less heat around the socket area

    Initial Results

  • The flow through the block is very acceptable
  • A pretty powerful jet of coolant shoots out the end of the returning hose when I pull it out of the reservoir (causing extreme bubbles when the jet hits the surface of the coolant in the reservoir)
  • I have not measured the temperature of the VRs or other components with my digital thermal sensor yet, but I can say for sure that the temperature of those components has SIGNIFICANTLY been reduced!!!
  • Before the VR block was installed, touching the VRs or especially those donut-shaped components with your bare fingertip resulted in instant pain
  • Now I can hold my fingertip on the donuts forever without worry of pain
  • The donuts are warm to the touch but by no means as hot as before (I would estimate 40’C now)
  • The capacitors as well feel cooler too

    Nick Poirier

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