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Re: PCI slots
- To: Mailing List Recipients <pci-sig-request@znyx.com>
- Subject: Re: PCI slots
- From: John R Pierce <pierce@hogranch.com>
- Date: Wed, 15 Jan 1997 15:16:46 -0800
- Resent-Date: Wed, 15 Jan 1997 15:16:46 -0800
- Resent-From: pci-sig-request@znyx.com
- Resent-Message-Id: <"cJeaX3.0.5M3.5RMto"@dart>
- Resent-Sender: pci-sig-request@znyx.com
At 02:08 PM 1/15/97 -0500, Dunlap, Randy wrote:
>I am looking for PCs (x86 CPUs) with a minimum of 6 slots,
>preferably more. If anyone has knowledge or information
>on this subject, please email me or the pci-sig reflector.
More that 4 slots requires a PCI bridge, as the PCI bus only allows 10
loads, the host bridge uses one load, the ISA/IDE bridge uses another, and
each slot requires 2 loads. If there are additional PCI peripherals on the
motherboard (such as a PCI scsi interface) this reduces the number of
available loads. There are motherboards out there that violate this spec...
I wouldn't use them. Furthermore, the common triton family of PCIchipsets
only supports arbitration on 4 masters.
Just happened to notice a new motherboard from SuperMicro with dual P6's and
8 PCI slots (plus 3 ISA slots). 4 of these PCI slots are behind a i960RP
coprocessor-bridge. Presumably this is setup as a straight bridge by
default, the data sheet says something about it running a WindRiver rtos or
some such..
This puppy looks like it will require a custom case as the additional 4
slots are about where the power supply would normally be.
http://www.supermicro.com I think it was the P6DNE or something similar.
-jrp
è | k