Christoph Anton Mitterer wrote: > Ruediger Dohmhardt wrote: > >> Jon Burgess wrote: >> >>> Many of the PCI cards currently on the market have the keys for >>> operation in both 5V and 3.3V slots >> >> >> Because those PCI cards have a "3.3V signalling" which is "5V tolerant". > > > Does this mean that the PCI-X slots in my board > (http://tyan.com/products/html/thunderk8we_spec.html) can use > conventional PCI cards with 3,3V or cards that work with both (3,3V and > 5V) in each case, too? As said before PCI-X is "3.3V signalling", whereas a PCI motherboard has either 3.3V or 5V signalling. There are (1) 5V PCI-cards, (2) 3.3V PCI-cards and (3) 3.3V PCI cards that are "5V tolerant" To answer your question: You can plug (2) and (3) into a PCI-X slot. Disadvantage: The whole PCI-X bus slows down to 33MHz, whenever it recognizes a single PCI-card. When the card "keying" is correct, only (2) and (3) can be plugged at all. Sometimes "keying" is incorrect. You can plug a 5V PCI-card into a motherboard with a 3.3V signalling environment and it may work, but it is neither reliable nor is it specified. Ciao Ruediger
