HP Xw460c - ProLiant - Blade Workstation Обзор - Страница 24

minimizes fan noise. HP recommends using at least eight fans. Using ten fans optimizes power and

cooling. See the appendix for more detailed fan and server population guidelines.

Scalable

Operating c-Class server blades requires installing a minimum of four fans at the rear of the c7000

enclosure. Up to ten fans can be installed so that cooling capacity can scale as needs change. Using

more fans allows the fans to spin slower to move the same volume of air, so each fan uses less power.

Eight fans are almost always more power-efficient than four fans. As the air flow rate increases, ten

fans are even more efficient (Figure 17). Slower spinning fans also create less noise.

Figure 17. General relationship between the number of fans in a c7000 enclosure and the associated power

draw

Precise ducting on ProLiant server blades manages airflow and temperature based on the unique

thermal requirements of all the critical components. The airflow is tightly ducted to ensure that no air

bypasses the server blade and to obtain the most thermal work from the least amount of air. This

concept allows much more flexibility in heat sink design. The heat sink design closely matches the

server blade and processor architecture requirements. For example, in the HP BladeSystem BL460c

server blade using Intel® Xeon® processors, HP was able to use a smaller, high-power processor heat

sink than in rack-mount servers. These heat sinks have vapor chamber bases, thinner fins, and tighter

fin pitch than previous designs. This creates the largest possible heat transfer surface in the smallest

possible package (Figure 18). The smaller heat sink allows more space on the server blades for

DIMM slots and hot-plug hard drives.