Welcome to the FPGA.guide introduction to cooling your VCU and BCU boards. This is the first part of 3, and applies to active and passive VCU units, as well as the BCU sold by SQRL.  

Heat dissipation is an important challenge for FPGA miners.  Unlike GPUs which were designed for consumer use, FPGAs don't always have the safeguards built in to keep users from burning their expensive hardware.  

Since the hashing algorithms generate a tremendous amount of heat, it's important to find the right strategy for cooling your board in order to hash at the maximum rate possible.  Currently theres 3 main methods.  

  1. Active fan cooling (ie.  Thomas Block's "bazooka")
DIY cooling bazooka by Thomas Block.

2.  Water Cooling (Richard @ TUL has designed a custom water block)

Custom water block designed for VCUs and BCUs

3.  Immersion (For larger operations, using BC-888 or Mineral Oil)

The TUL water block has proven to be very effective for these boards and confirmed by the leading bitstream devs.  And is definitely a LOT easier than doing your own immersion and heat exchange setup.  

Using TUL's waterblocks, the VCUs and BCUs are able to run the fastest bitstreams currently available at great temperatures.  Just check out this video that Richard posted.  

Also water cooling is much more accessible method for the majority of miners.  It doesn't require huge tanks of dielectric fluid or oil, nor DIY bazookas with big loud fans / swapping capacitors.

If you're interested in a water block from TUL, we partnered with them in covering and distributing the first waterblocks.  Check out the waterblock here while supplies last!

Today we'll show you how to attach the TUL water block to a Passive VCU1525.  This water block will work for Active and Passive VCUs, as well as the BCU1525.  

Remove VCU1525 Case

First we need to remove the original case.  Remove the 4 screws holding the top cover.  After these are removed, the top red cover should come off easily.

Second, remove the 2 remaining screws holding the stock back plate on.  Once removed, you can take off the entire back plate.  

Third, remove the 3 screws on the edge of the board to release the metal grill.

Finally, remove the 4 main screws that hold the heat sink.  

The heat sink and the block will not come off immediately though, as there are thermal pads and thermal paste keeping them attached.  

If you take a screw driver and lightly press, the heat sink will come off first exposing the VU9P chip.  

Then, lift at each corner of the board, until all the thermal pads detach from either the block or the components (some of the thermal pads may stick to the component).  Once the block comes off, make sure to remove any remaining thermal pads.

Before applying the water block, make sure you clean off the old thermal paste.   This is a crucial step for preventing voids/gaps/bubbles/poor seals.

Once cleaned, we're ready to install the TUL water block.

Installing Water Block

The water block designed by TUL is very easy to install.  The thermal paste and pads come pre-applied in the correct location, and there are only 3 small sets of screws which only take a minute to install.  Remove any covers protecting the thermal pads and line up your board with the block.  

Once they line up, simply flip, align the screws, and press down.  The thermal pads will contact the components, and fit snugly.  

Then, flip the board over, and align the custom back plate.  

After you align the back plate, again flip, align the screw holes, and press down.  

Once everything is aligned and in place, you'll want to start with the 5x  M2 screws first (ignore my photo, I did this in the wrong order and it was much harder to align)

Then once the 5 M2 screws have fixed and aligned the backplate to the top plate, you can easily screw in the 4 spring screws.  

Finally, attach the metal grill back to the board (though personally I feel this is optional)

Very important note, the fittings in our Thermaltake R240 water cooling kit did not fit this waterblock, to solve that we simply used L-shaped fittings.  

That's it!  

As you can see, this entire install process was very easy and straight forward.  It took no more than 20 minutes, and probably longer because this was a first-time for me.  For those of you with more experience, this will no doubt be a piece of cake.

We have very limited supplies of these water blocks, if you want one check out the waterblock here before they're sold out!

Best,

FPGA.guide Team