[mythtv-users] EPIA fan noise ?

Tim Tait t.tait at comcast.net
Tue Aug 3 10:40:17 EDT 2004


It is true that Request/Grant is unique per device. Though not all

>>>devices need Request/Grant, it is only needed for "Bus Mastering"
>>>peripherals. Of course, most high performance devices  (ethernet, IDE,
>>>VGA, and I am going to assume Video capture cards) do need it to achieve
>>>decent performance. The 2nd slot should be perfectly useable for a UART
>>>or Parallel port card:)
>>>      
>>>
>
>Agreed on all parts.
>
>To clarify, I shouldn't have said a two slot PCI riser card doesn't exist.  
>One has to differentiate between a passive risercard and an active one.  An 
>active one incorporates a true PCI-PCI bridge and thus can accomodate a full 
>PCI bus, i.e. four slots or even more on a single risercard.  I did not know 
>before the research I did yesterday that this actually existed (outside of 
>motherboards of course).
>
>  
>
>>>Tim
>>>      
>>>
>>I'm certainly no PCI expert but I have a generic 2 slot PCI riser, at least
>>that's how it was sold to me, and it runs my PVR-250 and Nova-t cards fine
>>on an EPIA-M 10000. I'm just wondering if anyone who thinks it doesn't work
>>has tried it. It sounds like I'm not the only one with success.
>>    
>>
>
>Hm.  Strange indeed,  Does it have any visible chips on it ?  If so, it is 
>very likely an active card (see above).
>
>Maarten
>
>  
>
>>Adam
>>    
>>

It wasn't that long ago when a motherboard might typically have only one 
PCI slot out of 3 or 4 that supported "Bus Mastering". If the driver is 
written to support operation in a non-BusMaster slot, then it might work 
OK but with reduced throughput or higher CPU loading.

If the riser is active (ie with a PCI-PCI bridge), doing a "lspci -tv" 
should show the extra layer and tell us what it is.

Does the riser pick up another connector on the motherboard as well the 
PCI one?

I don't own a PCI riser myself, but I am pondering what to get for my 
media center myhtbox so woud like to know.

Tim




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