PCI-X Vs. PCI Express
Parallel PCI standards with 5 V and 3.3 V are incompatible. Whatever is electronically possible is allowed mechanically.
Source: Digi PCI Technology Overview.
When looking at the comparison table below, you might be tempted to question whether PCI-X would be rendered superfluous. While PCI Express will mainly be around in desktop systems, PCI-X will remain the prevailing high-performance interface for high-end workstations and server systems. Finally, PCI-X 1066 will be able to provide up to 8.5 GB/s.
|PCI 2.3||32 Bit||33 MHz66 MHz||133 MB/s266 MB/s|
|PCI 64||64 Bit||33 MHz66 MHz||266 MB/s533 MB/s|
|PCI-X 1.0||64 Bit||66 MHz100 MHz133 MHz||533 MB/s800 MB/s1066 MB/s|
|PCI-X 2.0 (DDR)||64 Bit||133 MHz||2132 MB/s|
|PCI-X 2.0 (QDR)||64 Bit||133 MHz||4264 MB/s|
|PCI Express||1 Lines, 8 Bit||2.5 GHz||512 MB/s|
|PCI Express||2 Lines, 8 Bit||2.5 GHz||1 GB/s (Duplex)|
|PCI Express||4 Lines, 8 Bit||2.5 GHz||2 GB/s (Duplex)|
|PCI Express||8 Lines, 8 Bit||2.5 GHz||4 GB/s (Duplex)|
|PCI Express||16 Lines, 8 Bit||2.5 GHz||8 GB/s (Duplex)|
|PCI Express||32 Lanes, 8 Bit||2.5 GHz||16 GB/s (Duplex)|
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