User Guide • SC4-CONCERTO • CompactPCI
®
Serial CPU Board
Thermal Considerations
In order to avoid malfunctioning of the SC4-CONCERTO, take care of appropriate cooling of the
processor and system, e.g. by a cooling fan suitable to the maximum power consumption of the CPU
chip actually in use. The processor contains digital thermal sensors (DTS) that are readable via special
CPU registers or via PECI bus. DTS allows to get the temperatures of each CPU core separately.
Two further temperature sensors, one of it located in the system hardware monitor NCT7491, allows
for acquisition of the boards surface temperature and the thermal state of the onboard system
memory channel. Beside this the NCT7491 also keeps a PECI 3.0 master for CPU DTS monitoring and
supervises most of the supply voltages. A suitable software on Microsoft Windows
®
systems to display
both, the temperatures as well as the supply voltages, is Speedfan, which can be downloaded from
the web. After installation, both temperatures and voltages can be observed permanently from the
Windows
®
taskbar.
The SC4-CONCERTO is equipped with a passive heatsink. Its height takes into account the 4HP
limitation in mounting space of a
CompactPCI
®
board. In addition, a forced vertical airflow through
the system enclosure (e.g. bottom mount fan unit) is strongly recommended (>20m
3
/h or 2m/s
(400LFM) around the CPU slot). Be sure to thoroughly discuss your actual cooling needs with EKF.
Generally, the faster the CPU speed the higher its power consumption. For higher ambient
temperatures, consider increasing the forced airflow to 3m/s (600LFM) or more.
The table showing the supported processors above give also the maximum power consumption (TDP)
of a particular processor. Fortunately, the power consumption is by far lower when executing typical
Windows
®
or Linux tasks. The heat dissipation increases when e.g. rendering software like the Acrobat
Distiller is executed.
The processors support Intel's Enhanced SpeedStep
®
technology. This enables dynamic switching
between multiple core voltages and frequencies depending on core temperature and currently
required performance. The processors are able to reduce their core speed and core voltage in multiple
steps down to 800MHz. Additional a reduction of the graphics core clock (down to 350MHz) and
voltage is possible. This leads to an obvious reduction of power consumption resulting in less heating.
A further way to reduce power consumption is achieved by Intels voltage regulators belonging to the
IMVP8 standard. These regulators allows the processor to regulate the voltages to the cores, graphics,
system agent and other units separately depending on their performance needs. Parts that are
currently idle may switched off to save power.
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