[NTLUG:Discuss] Discuss Digest, Vol 91, Issue 14

[John Fields]

In production the biggest difference between PCI v2.1 and v2.2 was  
supporting 3.3 volts.

In v2.1 it was 'suggested' to add in the power supply work to supply a  
3.3v rail to the socket.  In v2.2 it was mandatory.

Since this 'feature' is not specific to a particular chipset, model #,  
etc. I don't believe you can determine it from software without a  
lookup table built from empirical testing - which to my googling eye  
does not exist.

There may have been a software feature first seen in v2.2, or was last  
seen on v2.1 but again detecting hardware features like that from the  
OS is not always possible.

So you have a card which either prefers or requires 3.3v.  If the card  
has circutry to convert 5v from that rail to 3.3v internally - you are  
golden; it will work in a v2.1.  But since the voltages are on  
different rails (socket pins) it shouldn't damage the card, just not  
power up and work.

Just plug it in and see (the old fashion testing method) ;)
JF


On Jul 24, 2010, at 12:00 PM, discuss-request at ntlug.org wrote:
>
> Howdy,
>  Does anyone know of a command I can run to tell me what version of  
> the
> PCI bus I have on a system?  I have a card that needs PCI 2.2 or newer
> and I have some systems I want to check for compatibility.  I have  
> found
> specs on some system, but not all.
> Good day,
> Ralph