How do we maximize performance from our PCs?

Prepared by Yousef DebsELEC 101

DECEMBER 5TH, 2007

CPUs Thermodynamics

• Electronic thermodynamics show that CPUs run more efficiently under cold temperatures

• Maximizing speeds and performance requires more voltage supplied to the CPU

• More voltage = More heat• With extremely low temperatures, heat

inefficiency is negated!• How do we get these freezing temperatures?

Is LN2 Viable?

• Liquid Nitrogen has been used to obtain the lowest temperatures

• LN2 cost efficiency? Safety? Ready availability?

• Phase Change cooling, the alternative

• Based on principles of refrigeration (HVAC)

What is Phase Change?

• Just like an AC, refrigeration principles can be used to cool computers as well as rooms!

• Phase Change refers to the evaporation of refrigerant in the unit’s evaporator

• Gas is compressed back to liquid• Liquid is cooled, and evaporated at extremely

low temperatures (R22 @ -42F)• How do we get an AC into a PC?

Components

Evaporator

• The evaporator is the CPU heatsink• Common OEM Computers have air cooled (fan

powered) heatsinks to moderate temperatures

• In a Phase change unit, the evap. block is the heatsink – freezing cold refrigerant is pushed through to cool the CPU at amazingly low temperatures

Heatsink Vs. Evaporator

Standard Heatsink/Fan Acrylic/Copper Evaporator

How does this work with a PC?

…Continued

Is there a market for this?

• Phase change and watercooling are extremely popular in computer/overclocking enthusiasm

• Prometeia and Vapochill• Retail value of Phase Change coolers is $600

Temperatures

• Vapochill and Prometeia advertise a full load CPU core voltage of approximately -20oC to -40oC!

• With these temperatures, almost double the stock voltage can be applied to the CPU, maximizing clock and bus speeds.

Results?

• Intel Quad Core Extreme Overclock

• Stock Frequency is 3.0ghz @ 1.35V

• This is an overclock of 175% @ 1.65V

• Cooler core temp. allows for more efficient gain on voltage rise

Conclusions

• Catered to enthusiasts, but a viable option for high performance computing

• LN2 and other alternatives are sparse, dangerous, and impractical

• Phase change cooling can be fit into a large ATX case form factor

• Extreme cooling allows users to maximize their PCs performance (Gaming)