Sun Fire V40z: Four Opterons in a 3U

Thermals, Acoustic

Cooling four processors crammed into a 3U is not an easy process – particularly considering the fact that the V40z does not utilize any active cooling directly on their CPU heat sinks. As we mentioned earlier, the two forward Opterons under the hard drive bay use two low profile copper heat sinks; the two rear processors use 4” high copper heat sinks with heatpipe risers. All air must be pulled from the front intake of the system (below and through the hard drive bays) all the way to the rear power supplies before it is exhausted.

The majority of cooling is provided by a bank of eight intelligent fans behind all four processors and another bank of four fans that sit between the forward and rear processors. In the image below, this bank is being removed from the system.

Click to enlarge.

All of Sun’s cooling fans are modular. The 60mm brushless fans can be pulled out of the system and replaced without powering down the system; obviously a benefit if a fan dies. All of these fans are also accessible with the top panel removed, which means that we don’t have to pull a hard drive or power supply in order to replace a fan either.

Click to enlarge.

Obviously, with twelve primary 60mm fans just providing the active cooling on the processors and memory, the Sun Fire V40z is not a quiet machine. Each redundant power supply also employs very loud fans, which gives the V40z a baseline operating noise level of 70 dBA even when the machine isn’t on. At a distance of twelve inches, we measured the Sun Fire V40z at a little over 85dBA. This is loud even by a rackmount standard, but in enterprise server configurations in dedicated server environments, this is certainly not a problem.

Even though the Sun Fire V40z is only 3U high, a standard 72-inch rack can only hold twelve V40z’s due to its thermal density, according to Sun documentation. Any more than twelve servers in a 72” rack wouldn’t allow for enough airflow.