PCI Low Profile
PCI Low Profile Position to standard PC/XT and AT add-in board's
THIS DRAWING SHOULD BE USED AS A GUIDLINE ONLY!!
Muco Technologies is not responsible for the hardware / brackets / board dimensions
ATTENTION ONLY PCI
- The card retention screw and the offset, or dogleg, direction on pci-sig compliant Low Profile PCI brackets is on the opposite side and in the opposite direction when compared to Full Height PCI brackets. Many chassis (other than Spinserver of course) do not yet correctly support this changed screw location, and many chassis manufacturers and some card manufacturers have previously adopted a merely shortened version of the standard PCI bracket format which do not comply with the LPPCI specification, these cards are generally known as " Low Height"," 80mm" or" 70mm" cards.
- The retention screw position has also been moved 1.35mm closer to the fold in the LPPCI bracket.
- The LPPCI spec assumes a 3.3Volt PCI slot. For those that don't know the difference - 3.3Volt 32Bit PCI bus has the polarising edge connector slot near the Bracket end of the gold plated fingers whereas the 5Volt (original) 32Bit PCI bus has the polarising slot furthest away from the bracket. This was achieved in the 3.3Volt 32 Bit bus standard by simply turning the PCI connector around end-for-end on the motherboard to prevent incorrect voltage cards from being inserted. In the 64Bit PCI world there are two totally different connectors because the added gold fingers and connector pins are always furthest away from the bracket (although it's hard to see that a 64Bit 5Volt spec will survive). The vast majority of cards are still 32 bit 5Volt and some cards are auto detecting and compatible with both 3.3 and 5Volt specs and have two cutouts for both orientations of PCI connector.
- The Height, size and retention bracket details for Low Profile PCI as developed by Intel and adopted by PCI-SIG are almost identical with those defined by Intel for the Low Profile version of the Communication and Networking Riser (CNR) Specification.
- Although the LPPCI PCB card height is tightly specified to be (almost exactly) at the same height limit as the LPPCI bracket, in practice there needs to be enough extra height available above the bracket for the retention screw head - around 3mm - so until all card manufacturers get their act together a card height of less than 68mm is probably acceptable in most Low Profile chassis in much the same way as the PCB's on full height PCI cards are often higher than the full height bracket (J.D.).
- Some card manufacturers (e.g. Intel and Adaptec) have produced a great range of LPPCI cards but they have been known to ship them with a full height bracket instead of an LPPCI bracket, check with your supplier to make sure! Intel actually suggested that we make a Low Profile bracket for their NIC cards so we are and they will be available shortly!
- As yet the AGP graphics card standard does not have a Low Profile version. (there are Low PCB height and 80mm AGP and PCI graphics cards out there that can be fitted with our brackets and an official standard is surely only a matter of time! (J.D.))