Overclocking Adventures: Dry Ice Party

Sitting at a cool minus 76 degrees Celsius at room temperature, dry ice cooling isn’t playing any games. For those not in the know, dry ice, or as it’s commonly referred to by overclockers, dice, is compressed carbon dioxide (CO2) gas. The gas is compressed and frozen to a solid state. At room temperature however, the substance sublimes (Chemistry: to volatilise from the solid state to a gas, and then condense again as a solid without passing through the liquid state). This is commonly understood as the substance evaporating. However, as mentioned, dice sublimes. There is no liquid state involved in the transformation from a solid to gaseous state. Therefore, the substance sublimates, not evaporates.

Wonderfully, as dice sublimes it fills the surrounding atmosphere with bountiful amounts of poisonous carbon dioxide. People, keep the windows open when messing with dice!

In all practicality, dice is not a 24/7 solution and does carry with it some inherent safety concerns. These concerns include the aforementioned atmosphere flooding, which highlights the toxic nature of CO2 gas to humans. Furthermore, cold burns, when contact between dry ice and human skin is made for any longer then a short instance (1-2 seconds), is another aspect to be mindful of.

Add to the mix that dry ice is a cooling resource with a constantly diminishing life span (at least at room temperature and atmosphere pressure), making it important to be mindful of the quantity of dice in the pot as well as in reserve to top up the pot as necessary.

Another important point, which will ultimately rule over all other factors, is that at room temperature and pressure, the dice is constantly subliming from its solid state to the gaseous CO2 most commonly known. This will have a strong influence when it comes to planning when a dice session is to take place, the availability of dice in co-ordination with the planned dice session and how long this session can run for. The rule of thumb being that 1-1.5kg of dice is used per hour, depending quite heavily upon the waste heat generated from the processor (or other heat source e.g. GPU, chipset etc) and the amount of voltages put through the processor/heat source.

Dry ice cooling can also be harmful to your precious hardware. Due to being minus 76 degrees Celsius at room temperature, condensation, specifically on heat emitting sources, can become an issue. This is where insulation is called upon to join the trip sub-zero.

The adventure to zero degrees and below can be a treacherous one. To aid in the journey, we solicited the use of insulation around the LGA775 socket and the copper CPU pot. A combination of closed cell foam, cork tape (also known as silly string), paper towel and open cell foam is used to assure an air tight, moisture free, sub-zero safe processor environment. These precautions are placed behind the socket area on the motherboard, over the actual socket and the surrounding area, as well as on the copper CPU pot used for housing the dice.