1. Field of the Invention
Embodiments of the invention generally relate to cooling devices for computer systems, and more specifically, to a counter rotating blower with individual controllable fan speeds.
2. Description of the Related Art
Electronic devices generally include a printed circuit board (PCB) with external and internal wiring for transferring signals between integrated circuits (and other electronic components) that are mechanically supported by and electrically connected to the PCB. As integrated circuit technology improves, more functionality can be built into smaller and smaller packages. An increased number of integrated circuits can be mounted on a PCB, thereby improving the performance of a common electronic device, a computer graphics card being just one example.
These improved integrated circuits, however, generate more heat while possessing smaller surface areas to dissipate the heat. It is important to have a high rate of heat transfer from the electronic device to maintain the temperatures of the integrated circuits within safe operating limits. Excessive temperatures may cause permanent degradation of the integrated circuits and thereby affect the performance of the electronic device.
A heat sink may be mounted on or adjacent to the surfaces of the integrated circuits to cool the electronic device. The heat sink is generally formed from a metallic material having a high rate of thermal conductivity to conduct heat away from the integrated circuits and dissipate heat to the surrounding air. In addition, a fan may be used to blow air across the heat sink to convectively draw heat from the heat sink for an overall increase in heat transfer from the integrated circuits.
Prior art configurations of heat sinks and fans have several drawbacks. One drawback is that current fan designs are not capable of directing a uniform air flow across the heat sink. This un-equal distribution of air flow causes one portion of the heat sink to cool better than another portion, thereby impairing the overall efficiency of the heat sink. Another drawback is that current fan designs are configured to continuously blow air at a high fixed speed, which uncontrollably increases acoustic noise and ineffectively consumes power in situations when less or even no air flow is required.
Accordingly, what is needed in the art is a more effective approach for handling heat transfer issues in electronic devices.
Embodiments of the invention include a blower for directing air flow across a heat sink. The blower comprises a first set of fan blades, a second set of fan blades, and a support plate disposed between the first set of fan blades and the second sets of fan blades. The first set of fan blades and the second sets of fan blades are simultaneously rotatable in opposite directions to direct air flow across the heat sink.
Embodiments of the invention include a cooling device for a computer system. The cooling device comprises a heat sink for cooling a component of the computer system, and a blower for directing air flow across the heat sink. The blower comprises a first set of fan blades, a second set of fan blades, and a support plate disposed between the first set of fan blades and the second set of fan blades. The first set of fan blades and the second set of fan blades are simultaneously rotatable in opposite directions to direct air flow across the heat sink.
Embodiments of the invention include a method of operating a blower for directing air flow across a heat sink. The method comprises causing a first set of fan blades of the blower to rotate in a first direction, simultaneously causing a second set of fan blades of the blower to rotate in a second, counter rotating direction to direct air flow across the heat sink, and causing a fan speed of the first set of fan blades and the second set of fan blades to be adjusted based on at least one of a temperature level measurement, an acoustic level measurement, and a power usage measurement.
One advantage of the embodiments of the invention is generating a uniform distribution of air flow across a heat sink, which maximizes the cooling efficiency of the heat sink.
So that the manner in which the above recited features of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the following description, numerous specific details are set forth to provide a more thorough understanding of the embodiments of the invention. However, it will be apparent to one of skill in the art that the invention may be practiced without one or more of these specific details.
A switch 116 provides connections between the I/O bridge 107 and other components such as a network adapter 118 and various add in cards 120 and 121. Other components, including universal serial bus (USB) or other port connections, compact disc (CD) drives, digital versatile disc (DVD) drives, film recording devices, and the like, may also be connected to the I/O bridge 107. The various communication paths shown in
In one embodiment, the GPU 112 or the parallel processing subsystem having multiple GPUs 112 incorporates circuitry optimized for graphics and video processing, including, for example, video output circuitry. In another embodiment, the GPU 112 or the parallel processing subsystem having multiple GPUs 112 incorporates circuitry optimized for general purpose processing, while preserving the underlying computational architecture, described in greater detail herein. In yet another embodiment, the GPU 112 or the parallel processing subsystem having multiple GPUs 112 may be integrated with one or more other system elements in a single subsystem, such as joining the memory bridge 105, the CPU 102, and the I/O. bridge 107 to form a system on chip (SoC).
It will be appreciated that the system shown herein is illustrative and that variations and modifications are possible. The connection topology, including the number and arrangement of bridges, the number of CPUs 102, and the number of GPUs 112, may be modified as desired. For instance, in some embodiments, the system memory 104 is connected to the CPU 102 directly rather than through a bridge, and other devices communicate with the system memory 104 via the memory bridge 105 and the CPU 102. In other alternative topologies, GPU 112 is connected to the I/O bridge 107 or directly to the CPU 102, rather than to the memory bridge 105. In still other embodiments, the I/O bridge 107 and the memory bridge 105 might be integrated into a single chip instead of existing as one or more discrete devices. Large embodiments may include two or more CPUs 102 and two or more CPUs 112. The particular components shown herein are optional; for instance, any number of add in cards or peripheral devices might be supported. In some embodiments, the switch 116 is eliminated, and the network adapter 118 and the add in cards 120, 121 connect directly to the I/O bridge 107.
Persons of ordinary skill in the art will understand that the architecture described in
The heat sink 230 may include any type or arrangement of heat exchange systems known in the art for conducting heat away from and thereby cooling one or more components supported by the circuit board 205. The heat sink 230 may be directly or indirectly coupled to, and/or positioned adjacent to, one or more components to be cooled. Examples of components that can be supported by the circuit board 205 and cooled by the heat sink 230 may include, but are not limited to, CPUs (such as CPU 102), CPUs (such as GPU 112), and other integrated type circuits.
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The first set of fan blades 222 may be disposed on top of the support plate 225 above the second set of fan blades 224. The first set of fan blades 222 may be oriented and rotatable in a first direction, such as a clockwise direction as indicated by reference arrow 221 (illustrated in
The blower 220 may be controlled by a control unit, such as the CPU 112 and/or another similar processing unit that is a part of the computer system 100, another computer system, and/or integrated into the circuit board 205 of the add-in card 200. The control unit may be a programmable logic controller with memory, mass storage devices, power supplies, clocks, cache, input/output circuits, and/or other components know in the art. The control unit may monitor and adjust the operating speeds of the first and second sets of fan blades 222, 224 based on one or more pre-determined conditions, including but not limited to temperature, acoustic, and power usage levels or measurements of one or more components of the add-in card 200 and/or the computer system 100. The control unit may monitor and/or receive signals corresponding to temperature, acoustic, and power usage levels or measurements of one or more components of the add-in card 200 and/or the computer system 100.
For one example, the control unit may be programmed to operate the first and second sets of fan blades 222, 224 at maximum fan speeds when the measured temperature of one or more components of the add-in card 200 and/or the computer system reaches or rises above a pre-determined temperature. For another example, the control unit may be programmed to operate the first and second sets of fan blades 222, 224 at minimum fan speeds (or fan speeds less than maximum fan speed) when the measured temperature of one or more components of the add-in card 200 and/or the computer system reaches or falls below a pre-determined temperature. For a further example, the control unit may be programmed to operate only one of the first and second sets of fan blades 222, 224 when the measured acoustic level or power usage of one or more components of the add-in card 200 and/or the computer system reaches or rises above a per-determined amount.
The operating speeds of the first and second sets of fan blades 222, 224 also may be adjusted by a user via the control unit. The user may select a desired fan operating speed (e.g. maximum fan speed, minimum fan speed, or any fan speed between maximum and minimum fan speed) of one or both of the sets of fan blades 222, 224, which selection may be communicated to the control unit to operate the blower 20 at the desired fan speed. The user may change or adjust the fan operating speeds as desired or based on temperature, acoustic, and power usage levels or measurements of one or more components of the add-in card 200 and/or the computer system 100.
During one operation of the blower 220, the first set of fan blades 222 and the second set of fan blades 224 may be rotated simultaneously in opposite (counter rotating) directions but at the same operating speeds to substantially distribute air flow uniformly across the surfaces of the fins 232 and the conduits 233 of the heat sink 230. The uniform distribution of air flow generated by the blower 220 maximizes the cooling efficiency of the heat sink 230 by removing heat uniformly from all of the surfaces of the heat sink 230. A non-uniform distribution of air flow across the heat sink 230 may result in one portion of the heat sink 230 dissipating heat at a greater rate than another portion of the heat sink 230. The operating speeds of the first and second sets of fan blades 222, 224 may be adjusted to achieve a desired heat dissipation rate via the heat sink 230.
The first and second sets of fan blades 222, 224 may be rotated at a maximum fan speed to maximize the amount of heat dissipated from the heat sink 230. Alternatively, the first and second sets of fan blades 222, 224 may be rotated at a minimum fan speed or any other fan speed that is less than the maximum fan speed. Alternatively still, the first set of fan blades 222 may be rotated at a maximum fan speed, while the second set of fan blades 224 are rotated at a minimum fan speed or any other fan speed that is less than the maximum fan speed, and vice versa. The fan speed of one or both of the sets of fan blades 222, 224 may be adjusted between the minimum and maximum fan speeds. Lowering of the fan speed of either of the sets of fan blades 222, 224 from the maximum fan speed may reduce the amount of noise generated and power consumed by the blower 220.
During another operation of the blower 220, where less heat dissipation is needed for example, only one of the sets of fan blades 222, 224 may be operated while the other set of fan blades 222, 224 remains idle or non-rotating. In this instance, the blower 220 may be configured to minimize noise (acoustic) and/or power consumption. Operating only one of the sets of fan blades 222, 224 may generate less noise and consume less power than when operating both of the sets of fan blades 222, 224.
As shown, a method 300 includes an initial step 305 of causing the first set of fan blades 222 to rotate in a first direction. At step 310, the second set of fan blades 224 may be simultaneously caused to rotate in a second, counter rotating direction to direct air flow across the heat sink 230. The simultaneously rotating first and second sets of fan blades 222, 224 may be rotated at a first fan speed. The first fan speed may be the minimum or maximum operating speed that the fan blades 222, 224 may be rotated. At step 315, when desired by a user or upon receiving a signal corresponding to a pre-determined condition, the method may include causing the fan speed of the first and second sets of fan blades 222, 224 to be adjusted based on at least one of a temperature level measurement, an acoustic level measurement, and a power usage measurement. The pre-determined condition may be monitored by a user and/or the control unit. The fan speed of the first and/or second set of fan blades 222, 224 may be adjusted to a second fan speed that is different (greater or less) than the first fan speed, via the control unit. Subsequent to, or as an alternative to step 315, at step 320, when desired by a user or upon receiving a signal corresponding to a pre-determined condition, the method may include causing one of the sets of fan blades 222, 224 to stop rotating while continuing to rotate the other one of the sets of fan blades 222, 224, via the control unit. The pre-determined condition may be a temperature, acoustic, and/or power usage level or measurement of one or more components of the add-in card 200 and/or the computer system 100.
In sum, embodiments of the invention include a blower having individually controllable, counter rotating sets of fan blades for generating a uniform distribution of air flow across a heat sink. Each set of the counter rotating fan blades may be individually controlled by a control unit. The blower may be operated, and in particular the fan blade operating speed may be adjusted, using one or both sets of fan blades based on one or more pre-determined conditions. The pre-determined conditions may include at least one of temperature, acoustic, and power levels and/or measurements of one or more components of the computer system.
The counter rotating sets of fan blades provide the advantage of generating a uniform distribution of air flow across the heat sink, which maximizes the cooling efficiency of the heat sink. An unequal distribution of air flow, as generated by prior blower designs, results in one portion of the heat sink dissipating heat at a greater rate than another portion of the heat sink, thereby inhibiting efficient use of the heat sink. An additional advantage of the blower is that the counter rotating sets of fan blades may be individually controlled to optimize performance of the blower. In particular, only one set of fan blades may be used for low temperature conditions, thereby consuming less power and reducing acoustic noise, while both sets of fan blades may be used for high temperature conditions, thereby maximizing heat transfer.
While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.