Connection between GT/s and Go/s
youscoul
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youscoul Posted messages 150 Status Member -
youscoul Posted messages 150 Status Member -
Hello,
I want to buy a Xeon X5570 processor, but I see the specifications that I can't understand. Indeed, I wasn't familiar with the QPI bus, but worse, they talk about GT/s and Go/s. For example, 6.4GT/s is equivalent to 25Go/s. How is that possible? So 1T = 4 bytes? And my machine is 64 bits so the transfers are actually 8 bytes, right?
Thank you in advance
Configuration: Windows XP / Internet Explorer 7.0
I want to buy a Xeon X5570 processor, but I see the specifications that I can't understand. Indeed, I wasn't familiar with the QPI bus, but worse, they talk about GT/s and Go/s. For example, 6.4GT/s is equivalent to 25Go/s. How is that possible? So 1T = 4 bytes? And my machine is 64 bits so the transfers are actually 8 bytes, right?
Thank you in advance
Configuration: Windows XP / Internet Explorer 7.0
1 answer
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Hi,
To answer you regarding GT/s and Go/s, we are used to hearing about Gbps (Gigabits per second) but GT/s stands for gigatransfers per second.
What's the difference? It's, very roughly, a difference in encoding that thus requires using more bits. GT has nothing to do with terabytes.
Most of us are used to seeing bus speeds specified in Gbps, or gigabits per second, but GT/s stands for gigatransfers per second. What's the difference?
The difference has to do with the encoding of the data. Because PCIe is a serial bus with the clock embedded in the data, it needs to ensure that enough level transitions (1 to 0 and 0 to 1) occur for a receiver to recover the clock. To increase level transitions, PCIe uses "8b/10b" encoding, where every eight bits are encoded into a 10-bit symbol that is then decoded at the receiver. Thus, the bus needs to transfer 10 bits to send 8 bits of encoded data.
For more info, search online (here)
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