Method and apparatus for minimizing signal loss in transit
Techniques for minimizing signal loss in transit are described. Data signals lose their strengths while traveling across conductive passages such as cooper wire, cooper strip, Printed Circuit Board (PCB), etc. There are two major factors that affect the signal loss: the distance and the speed. To minimize signal loss while maintaining higher rate data signals for I/O, substantially lower rate data signals are used in transit between two interfaces over a signal path.
1. A method for minimizing signal loss in transit over a printed circuit board (PCB) midplane in a blade server, the method comprising:
receiving a plurality of data signals at a predefined first rate at a first end of the PCB midplane;
transmitting the data signals at the first rate from the first end of the PCB midplane to a second end over the PCB midplane;
selecting one of the data signals by a switch; and
converting at the second end the one of the data signals by a data rate converter to a predefined second rate before the one of the data signals reaches an I/O module, wherein the second rate is substantially higher than the first rate such that the one of the data signals is transmitted at a much higher speed within the blade server while the signal loss is minimized in transit over the midplane in the blade server.
2. The method as recited in claim 1 , wherein the first end includes a plurality of interfaces receiving the data signals in accordance with a first protocol.
3. The method as recited in claim 2 , wherein the first protocol is PCI-E.
4. The method as recited in claim 2 , wherein the second end includes the switch that continues transmission of the one of the data signals in accordance with a second protocol.
5. The method as recited in claim 4 , wherein the second protocol is Infiniband.
6. The method as recited in claim 1 , wherein the midplane includes one or more conductive passages guiding the data signals from the first end to the second end, the conductive passages having inherent characteristics of causing higher signal loss when the data signals are transmitted at second rate.
7. The method as recited in claim 1 , further comprising:
receiving a data signal at the second rate at the second end;
converting the data signal at the second rate to the first rate at the second end; and
transmitting the data signal at the first rate via the switch to a destination via the midplane.
8. The method as recited in claim 1 , wherein the first end includes a plurality of blades in the blade server and the second end is the switch coupled to the I/O module of the blade server.
9. A blade server with a capability of minimizing signal loss in transit, the blade server comprising:
a plurality of first interfaces, transmitting a plurality of data signals at a predefined first rate from a first end in accordance with a first protocol over a midplane to a second end in the blade server;
a switching means including a data converter, in the second end, coupled to the midplane and receiving the data signals, selecting one of the data signals to be converted from the first rate to a predefined second rate; and
an I/O module to receive the one of the data signals at the second rate, wherein the second rate is substantially higher than the first rate such that the one of the data signals is transmitted within the blade server at a much higher speed while the signal loss is minimized in transit over the midplane in the blade server.
10. The blade server as recited in claim 9 , wherein each of the first interfaces is from one of blade computers in the blade server.
11. The blade server as recited in claim 9 , wherein each of the first interfaces is a network interface on one of a plurality of blade computers of the blade server.
12. The blade server as recited in claim 11 , wherein the blade server includes the plurality of blade computers coupled to a printed circuit board (PCB) midplane on one side and the one I/O module on other side.
13. The blade server as recited in claim 12 , wherein the I/O module includes a pair of identical I/O modules for ensuring reliability of the blade server with redundancy.