Category Archives: PCIe

How To Perform PCI Thermal Management

PCI Thermal Management for embedded compuiting

Click this pic to go right to a case study on thermal management of a PCI card

PCI bus has been around a number of years having been invented by Intel in 1992.   The primary reason for its invention was the need for a high speed bus to replace the slower ISA bus with the advent of Intel’s Pentium Processors.  The length of time the bus has been in existence and it’s widespread use often leads to as many thermal management challenges as there are applications using this bus.

PCI bus have evolved since that day with the coming of PCIx, PCIe, cPCI and more.   The fact this bus has been been forked to other variations speaks to its sound design and to the power of the Intel architecture as it has grown into use in many applications from computer servers, to telecommunications to embedded. PCI, from the beginning, was envisioned as a specification the entire technical community could take advantage of, and the organization insuring that is PCI-SIG.  As they note in their charter:

Founded in 1992, Peripheral Component Interconnect Special Interest Group (PCI-SIG) is an association of 700+ industry companies committed to advancing its non-proprietary peripheral component interconnect (PCI) technology by:

  • Defining PCI specifications to deliver required I/O functionality
  • Adapting PCI technology to future applications
  • Maintaining backward compatibility with previous specifications
  • Supporting industry-wide product development by offering compliance and interoperability test support

So how can an engineer go about cooling a very hot PCI based board?   The following case study shows one such example.  It is a PDF, is free and no registration is required.   Here’s the abstract:

  • An embedded computing manufacturer needed to determine the thermal characteristics of their new Packet Processor board
  • The key component is the 16-core, 500Mhz, Cavium CN3860 NSP with up to 56W power dissipation
  • Develop a cooling solution that would improve MTBF, be cost optimized, and use only air
  • Replace the current active heat sink for a passive heat sink.

See the solution to this electronics cooling challenge for PCI at this link here: Thermal Analysis and Heat Sink Design for a Cavium Based PCI Network Processor Card.