Messages in this thread | | | Date | Wed, 22 Sep 1999 03:29:04 +0000 | From | Steve Underwood <> | Subject | Re: Linux and real device drivers |
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Stephen Frost wrote:
> On Tue, 21 Sep 1999, Bret Indrelee wrote: > > > PCI bus normally runs at 33 MHz. It takes at least two clock cycles to do a > > Just to butt in, this certainly is not always going to be the case. > Indeed, there are a number of folks who are working at running at higher PCI > bus speeds. You're making a not-so-small assumption that the processer will > always greatly out-speed the device it's talking to...
There is a proper standardised 66MHz variant of PCI, which is used on a lot of Alpha, and (I think) Xeon boards. There's 64bit PCI, too, with an extra connector for the extra lines. Most dedicated x86 users seem unaware of these.
66MHz PCI is actually somewhat troublesome. Most real 66MHz implementations seem to have just 2 card slots per bus. That only just scrapes through the definition of a bus. Add more slots and things get flakey.
Steve
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