Computer Hope

Hardware => Hardware => Topic started by: qz33 on January 30, 2008, 09:25:02 AM

Title: PCIe Backwards Compatible?
Post by: qz33 on January 30, 2008, 09:25:02 AM: Just real quick-

I know old PCI cards can be used with PCIe connectors but the speed will be old PCI speed.

Can PCIe cards be used with PCI connectors? I doubt it.
Title: Re: PCIe Backwards Compatible?
Post by: socrates on January 30, 2008, 09:29:34 AM: no they cannot.
Title: Re: PCIe Backwards Compatible?
Post by: socrates on January 30, 2008, 09:32:07 AM: I should say a bit more.

The reason why is because the pci slot is too old of technology to recognize the pci-e card. However, the pci-e slot is newer technology, and is therefore able to read the new and old technology (pci-e cards and pci cards).
Title: Re: PCIe Backwards Compatible?
Post by: Deerpark on January 30, 2008, 09:49:38 AM: And to add to that.... as far as I know PCI-E is only compatible with PCI on the software level. You can't actually install a PCI card in a PCI-E slot.
Title: Re: PCIe Backwards Compatible?
Post by: socrates on January 30, 2008, 09:51:31 AM: Quote from: Deerpark on January 30, 2008, 09:49:38 AM
And to add to that.... as far as I know PCI-E is only compatible with PCI on the software level. You can't actually install a PCI card in a PCI-E slot.

yes, I believe that's correct.
Title: Re: PCIe Backwards Compatible?
Post by: qz33 on January 31, 2008, 08:12:39 AM: Quote from: socrates on January 30, 2008, 09:51:31 AM
Quote from: Deerpark on January 30, 2008, 09:49:38 AM
And to add to that.... as far as I know PCI-E is only compatible with PCI on the software level. You can't actually install a PCI card in a PCI-E slot.

yes, I believe that's correct.

If this is true then what purpose does PCI-E backwards compatability with old PCI cards serve?
How come this is listed as an advantage for PCI-E? I thought old cards were still supposed to be useable with the new slots.
Title: Re: PCIe Backwards Compatible?
Post by: socrates on January 31, 2008, 09:13:01 AM: Good question.
Title: Re: PCIe Backwards Compatible?
Post by: Deerpark on January 31, 2008, 10:25:43 AM: The point is, if you have software that is purpose written to interface with a specific PCI card, you can change the card to an equivalent PCI-E card and the software will continue to function.
The average user will probably never be in a situation where this is an advantage but for enterprises this could potentially save them a lot of money. It will make it a lot more compelling to switch to PCI-E architecture if companies only have to change their hardware and not rewrite their software.