Difference Between PCI 2.0 and PCI 2.1

PCI 2.0 vs PCI 2.1

Peripheral Component Interconnect Express, also abbreviated as PCIe, is an expansion card used for connecting sound, video, and network cards to the mother board of a computer. PCI Express 2.0 was released on the 15th of January, 2007. The PCI 2.0 standard card has the capacity to double the per-lane throughput from the PCIe 1.0 standard card’s 250Mbps to 500 Mbps. The PCI-SIG (Peripheral Component Interconnect Special Interest Group) announced that the PCI 2.0 standard’s software architecture was improved to have features such as point-to-point data transfer protocol. PCI 2.1 also includes all the features of the PCIe 2.0 standard card. The PCIe 2.1 standard card supports a large part of the management of the system.

PCIe 2.0 with a 32-lane PCI connector (x32) can provide a total throughput of 16GB/s. The PCIe 2.1 supports both 3.3V and 5V. It also supports 64 bit slots and 66MHz capability. PCIe 2.1 with a 32-lane PCI connector can provide a throughput of 266Mbps at 66MHz, and with a 64-lane PCI connector, can provide a throughput of 532 Mbps at 66 MHz.

PCIe 2.0 includes features, such as dynamic link speed management which helps to control the speed at which links operate. It also supports features such as link bandwidth notification, capability structure expansion, access control services, completion timeout control, function level reset, and power limit redefinition. PCIe 2.1 includes features such as protocol, electrical, mechanical, and configuration specifications for PCI Local Bus components and expansion boards. The electrical specification defines both 3.3V and 5V signaling environments. The PCIe 2.1 supports multiple families of processors which also include future generation processors and 64-bit addressing. There is also a provision made for forward and backward compatibility with 33MHz and 66 MHz add-in boards and components. The PCIe 2.1 offers parity on both data and address.

Summary:

1. PCIe 2.1 provides higher performance than the PCIe 2.0 by facilitating a transparent upgrade from a 32-bit data path to a 64-bit data path at 33MHZ and 66MHz.
2. PCIe 2.1 supports both 3.3 and 5 Volt signaling environments while PCIe 2.0 supports only 3.3V.
3. PCIe 2.1 supports a large part of management and troubleshooting systems which will be implemented in the upcoming PCIe 3.0 version.
4. PCIe 2.1 has the same speed as that of the PCIe 2.0 version.
5. PCIe 2.1 provides parity on both data and address while PCIe 2.0 doesn’t include this feature.