Can I Use an Old PCI(e) Card on a Newer PCI(e) Slot?

Issue Details

• I recently purchased a new computer or motherboard and it only has PCIe 3.0 slots and I have some old NI PCIe cards that were working on older (PCIe 2.0) slots. Can these cards still be used with my new motherboard?
• Will my PCI 2.2 card work in a PCI 2.3 slot?
• Are PCI revisions backwards compatible?

Solution

Generally, PCI revisions are backwards compatible. This means that older PCI(e) cards can be used in newer PCI(e) slots e.g. PCIe 2.0 card in a PCIe 3.0 slot.

However, a few caveats should be noted:

• Older PCI(e) cards will not be able to access the full bandwidth of the newer PCI(e) slot.
  • For example,  PCIe 2.0 x16 is equivalent to PCIe 3.0 x8. The card's performance should not be limited since it is limited by it's own hardware generation.
• It is important to check the differences between your PCI(e) revisions, as some hardware changes may be incompatible.
  • For example, PCI 2.3 removed support for 5V-only keyed cards. This means that Universal (3.3V and 5V keyed) PCI 2.2 cards should work, but 5V-only PCI 2.2 cards would not.