Friday, February 13, 2009

Processors for Higher Temps

Higher Temperatures for Data Centers talks about emerging environmental standards that could well lead to increasing ambient temperatures in facilities. All other things being equal, higher ambient temperatures will lead to higher component temperatures.

In many cases, the maximum processor case temperature (Tcase) is the limiting factor for how high the ambient temperature can be raised. The Tcase limit is established by the semiconductor vendor as the maximum case temperature that the chip can experience and still meet the vendor's reliability goals.

This can put a crimp in plans to use outside air for cooling. In most likely data center locations, there are occasionally warm days that would increase the inlet temperature to the servers to the point that the processor Tcase would exceed the vendor's specified ratings.

The telecommunications market has had this issue for years.
NEBS-rated equipment for central offices generally has to operate at 40°C ambient temperature, but they also need to operate at 55°C for short periods (up to 96 hours at a time and up to 360 hours per year).

To address the needs of the NEBS market, Intel provides some of their processors with
dual Tcase ratings: one long-term T-case rating and a second short-term Tcase rating that is 15°C higher for up to 360 hours per year.

These processors with dual Tcase ratings may be a good fit for systems in data centers that use air-side economizers.


  1. Great points but one thing I want to point out is I beleive if you design for higher temperatures you will still be able to meet the same processor long as you are willing to give a little on density....its all about making the right trafeoffs....which was my point in the Intel Great debates on density

  2. Christian,

    How much is "a little" that can be given on density? 25%? 50% 100% (half-density)?

    To increase cooling effectiveness of the heat sinks on processors (and DIMMs), you generally have to either increase the size of the heat sink (base plate area or fin height) or increase the air flow. Increased airflow generally results in more noise. What acoustic levels are acceptable?