On Thu, 27 Dec 2007 10:04:09 -0600, chrisv
<chrisv@nospam.invalid> wrote:

>Robert Redelmeier wrote:
>
>>I used to be very concerned about integrated graphics spoiling
>>desktop performance by stealing bandwidth. Then I tested my
>>new Xmas present: 2.44 GB/s increases to 2.50 with a separate
>>vidcard. Round-trip latency goes from 82 to 81ns. I'm very
>>underwhelmed and doubt I'll buy a vidcard for it.
>
>Reminds of of when I was made fun of because I didn't really care that
>the new motherboard that I was considering didn't have the new
>Ethernet controller that didn't "steal bandwidth" from the PCI bus.
>
>I asked, "What is the PCI bus for? To sit there looking pretty or to
>provide bandwidth to devices that need it?" and "How much of my PCI
>bandwidth is my Ethernet connection, usually limited by a ~1Mb/s
>Internet connection, using-up anyway?"

You have a reasonable point, if it were that simple.

How does one decide they would only use networking for a
1Mb/s internet connection, in the entire life of the system
and possibly even the next owner of the system if you hope
it won't die before you want to replace it- so the next
owner who has different needs might benefit. Buying parts
well designed encourages good design, puts more profit into
doing so and benefits us all so long as the price is not
excessive, and it will tend not to be excessive when one
superior solution is universally accepted and sold in
greatest volume (so long as there is still competitive
tech).

Multiple PCI devices don't just have to additively use more
than the PCI bus throughput, it is a matter of timing as
well. Recall certain Creative Labs sound cards plus another
PCI device, did not additively use 120+ MB/s, but did have
the potential to often stutter in sound playback.

Mentioning the potential issues of devices that use the PCI
bus is reasonable. Some people have PCI sound, drive
controller, TV tuner or other cards as well, or may add them
in the future. Avoiding 33Mhz/32bit PCI bussed devices when
possible is a good idea (assuming chipset integral or PCI
Express, not USB).