PCI runs at 66MHz when devices allow?

[Leo V]

Saw this somewhere a while ago and it came back to haunt me:

Is it true, that if all your devices are PCI2.1 (or 2.2) compliant, and you have a recent motherboard, then the PCI bus implicitly sets itself to 66MHz instead of 33MHz? (Effective 266MB/sec throughput, instead of 133). I also recall that some BIOS settings must be set correctly to allow this (Delayed Transaction and some other setting).

Well?

 

[Adul]

i think you are talking about compatibility with a 64 Bit pci slot. They run at 33/66 Mhz.

 

[Leo V]

Oh, okay. I think whoever's post I read were confused

 

[nightowl]

Yes it is 64 bit slots that run at 66 MHz but the PCI card needs to have a notch at the front of the connector. Check here for more information.

 

[Schola]

I think nightowl you are correct. The PCI slot can run at either 32bit 33mhz or 64bit 33/66mhz. Its in anads serverworks review.


Here you go

Anand explaining PCI Slots on the Server works