Are the specs just suggestions ? (was: Fw: PCI Clock)

[Marco Brambilla <marco-tpa.brambilla@st.com>]

Ray Clark wrote:

[...]
> time?  Vendors could make it a sales point - "Our boards meet the spec,
> don't crash your system like those OTHER guys..."

Yeah, specs seem to be just suggestions.

While following the integration of a device of ours, we found
motherboards which were blatantly violating the max retry time, the
number of wait states that can be inserted between data phases and some
other spec issues, even if they are declaring PCI 2.2 compatibility.

Recently, we have seen a motherboard which, depending on the address
where buffers are located in RAM, DOES NOT ALLOW BURSTS by master
devices on the bus. Each (single) data phase is preceded by 5 retries.
They are selling it as a high performance board, but moving 16
doublewords takes 10 usec. 

Sure, they're not violating the specs here, but what about performances
? The data sheet that you can find on the web obviously says nothing
about it.
Needless to say, no word from the "tech support".

Ciao, Marco.

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