64 bit PCI boards

[JohnGalt47]

I bought a MSI dual processor mobo that has 2 64 bit slots. I also bought a Tekram SCSI 160 controller card. I was surprised when the card would not fit in the mobo's slot. The configuration of the pins and cutouts is different.

Would someone please explain why there are 2 different configurations?

 

[bozo1]

Does it fit at all? (even if the card doesn't plug into the part of the slot nearest the back of the case?)

The small portion of the PCI slot near the back of the case is used for 3.3-volt PCI cards. Your Tekram card is a 5-volt only card. Some 64-bit slots will support both voltage cards, you just have a portion of the PCI slot with none of the card plugged into.

Your card should physically fit. Where you may run into trouble is that the Tekram U160 is a 33MHz card and your 64-bit slots, depending on the motherboard, may be 66MHz only.

My understanding is the 760MPX chipset, if that is what you are using, supports only 3.3 volt cards, regardless of the slot keying. The 760MP chipset supports 5-volt cards.

 

[Peter]

You must have gotten an ooooold revision of the Tekram card. The keying is to identify 3.3V and 5V slots and cards. Now since 66-MHz-capable PCI busses are 3.3V-only, the slots are keyed 3.3V-only to prevent people from inserting 5V-only cards (dual-mode cards would fit). The very first revision of the Tekram U160 card was 33 MHz 5V-only, and as you found out already, won't do and won't fit in a 66 MHz capable PCI slot.

If you bought that card new, return it, and insist on getting the latest revision which is both 66-MHz-capable and of course 3.3V.

regards, Peter