The document describes the design and creation of a custom liquid nitrogen GPU cooling container called the Clover Pot. It discusses the author's history with overclocking and benchmarking computers, which led them to build their own container to push components further. The summary describes the design and machining process, including CAD design, 3D printing prototypes, and CNC machining of aluminum and copper parts. Benchmarking tests with the completed Clover Pot achieved a top 69 ranking globally in the Aquamark3 GPU benchmark.

1. THE CLOVER POT
CUSTOM LIQUID NITROGEN GPU COOLING
CONTAINER
Chance Coats

2. Personal Introduction

3. Building Computers
 I assembled my first computer in 2009.
 Incremental upgrades annually since then.
 Saving money lead me to push my
components as far as possible.
 Overclockers.com became my main forum in
early 2009 and I began overclocking.
 After joining the Benchmarking team in 2011,
I have been competing online ever since.

4. Benchmarking and Extreme
Cooling
 Benchmarking results are tracked on
“HWBot.org”
 Extreme cooling is not required to compete.
 I felt a strong desire to push my hardware
even further past typical limits. Ambient
cooling no longer allowed me to reach my
goals.
 I purchased my first CPU container and used
dry ice.
 After gaining enough experience with dry ice, I
switched to liquid Nitrogen for cooling.

5. Why use Extreme Cooling ?
 As I pushed my devices further, power
consumption and temperatures quickly got out
of control.
 Sub-ambient cooling methods allow for greater
power dissipation, lower operating voltages,
and most importantly higher clock speeds.

6. Building my own Container
 CPU containers are extremely useful, but GPU
containers offer increased performance results
for graphics cards when using extreme
cooling.
 Commercially available GPU containers are
expensive and difficult to find in good
condition.
 My advanced drawing class offered me access
to heavy duty machining equipment.
 I enjoy getting my hands dirty and working
through projects.

7. Clover Pot – Design Process

8. Hand Drafting
 My initial designs were all done by hand using
pencil and paper.
 The first draft was very far from the finished
product.

9. CAD Design Process
 My hand sketches went through multiple
revisions as I learned about the machining
process and its limitations.
 After finding a general design, I moved onto
CAD drawing using AutoDesk AutoCAD.
 Once switching to electronic drawing, I was
allowed more freedom to explore base designs
and could visualize the final product in 3D.

10. Creative Design Process
 Trial, error and testing lead to my final design.
 Early revisions would change as often as
everyday.

11. The Clover Pot was born
 My final design revision gave me a strong
sense of achievement. I had created a unique
design with strong performance analysis
results.

12. Intermediate Design Step
 Because school gave me access to a 3D printer,
I was able to take my design process one step
further after finalizing. The design was created
at half scale using extruded ABS plastic.

13. Design Choices
 A two-piece design was chosen for cost
reasons.
 Copper was used as the base material to offer
superior thermal conductivity near the GPU
core. The increased specific heat of Copper
also offered better load handling properties.
 Aluminum was used for the top of the
container. Lower cost allowed the container to
have a 2-3 fold increase in volume with a slight
increase in cost.

14. Machining Process

15. Materials and Tools
 After finalizing my design, I purchased the raw
materials and specialized tools necessary to
machine my design.

16. Design Specifications and
Precision
 I set lofty goals for myself when machining this
project. Having no prior experience using a 3-
axis mill, I knew the learning curve would be
steep.
 I set a goal of ±0.01’’ tolerances for my general
machining, and ±0.005’’ tolerances for the
mating surfaces between the halves of the
container.
 I met my goal for most of the project, but
unfortunately did not meet these specifications
for all cuts. In the end I was very happy with

17. The Container Top
 For reasons including material cost, material
hardness and design complexity, I chose to
start with the top half of the container.
 The general process of machining includes
facing and squaring materials before any cuts
are made.
 Raw materials are often close to square, but
not close enough for precise machining.
 All materials were faced to remove major
surface imperfections and squared for precise
machining.

18. Container Top Machining
 The top half of the container is essentially a
hollow metal tube made to mate with the base
of the container.

19. Base Machining
 After successfully completing the top half of
the container and meeting nearly 100 percent
of my specifications, I moved on to machine
the copper base.
 This half of the container was considerably
more complex and required finer
measurements as well as nearly three times
as long to machine.

20. GPU Core Contact Patch
 A key aspect of the base was the section designed to
make contact with the GPU core when in use. This
section required a very smooth finish to provide optimal
heat exchange, but was left rough for the better part of
the machining process.

21. Internal Base Design
Challenges
 During the design and revision process, I
decided on a relatively complex base design.
This offered superior surface area while still
maintaining a large amount of mass near the
core contact patch.
 Due to time and machine constraints, the
design was simplified during the process.
 Testing after completing the project has shown
the container still offers strong performance
and load handling characteristics.

22. Internal Machining
 Once the outside of the container was completed, I
began machining the internal surfaces and the surfaces
used for mating with the top half of the container.

23. Final Internal Machining
 Seen below is the base just after internal machining was
completed.
 Visible in the holes is the cutting oil used throughout the
process to ensure smooth cutting and proper cutting
head cooling.

24. Completed Internal Surfaces
 After many hours revising the original design
and machining the new features, I had nearly
completed the base of the container.
 The final steps of the base included drilling
and tapping holes used to attach mounting
brackets.
 These brackets were designed for smaller
aluminum plates and cut using a CNC
machine.

25. Attached Mounting Hardware
 Once the brackets were cut and all holes were
tapped, the only remaining step was to mate
the upper and lower sections of the container.

26. Clover Pot Results

27. Benchmark Testing
 After spending approximately 4 months on this
project split between design and machining, I
was itching to test the finished container in the
real world.
 In the world of benchmarking, there are
programs to test nearly all aspects of a
computer. From CPU and memory to GPU and
overall system performance, the list of
benchmarks is incredibly long.

28. Aquamark3
 Aquamark3 is a GPU specific benchmark
created in 2003 to test the rendering power of
high powered graphics cards.
 Despite its age, world records in this
benchmark are still fought over.
 After hours of pre-testing, I was ready to
freeze one of the graphics cards I had
purchased specifically for benchmarking.

29. Number 69 in the World

30. Really Cool Pictures

31. Hardware Setup Used
 I’ve always been fascinated by pushing
computer hardware to the limits. Results and
pictures of my sessions provide a view into the
insane world of competitive overclocking.
 The hardware used for the previous results
include:
 Intel Core i7 processor and High Performance
DDR3
 Asus Motherboard and Nvidia Graphics Card

32. Mid Session

33. Aftermath

34. Thank you very much for this opportunity to tell
you about myself.
Questions?
Thank you!