Re: [CAD_CAM_EDM_DRO] Mach3 & "integrated video"

Danny Miller wrote:

>Well, what confuses me is that isn't the parallel port on the
>southbridge and video on the northbridge anyways?
>
>

The problem with chipset-integrated video is that it requires access to
memory for video refresh as well as operations on display data. When
the chipset decides to access memory for the video controller, the CPU
can't get access to main memory. If an interrupt fires and all of the
data and code aren't in cache, the CPU has to wait until the video
controller finishes its work before the chipset will fetch data into the
CPU caches. This causes little hiccups that would normally be
insignificant, but when you're trying to get interrupt response to be
accurate to a few microseconds, they're terrible.

>Logically I'm not sure if northbridge traffic would interfere with
>southbridge. But even assuming it could, the real mysterious part there
>is that doesn't an integrated video system run through the northbridge
>pretty much the same as if it were running through the AGP port?
>
>

For one of the old Intel AGP cards that actually used main memory for
display data, yes, they may be pretty similar. Those cards were dog
slow so they were never very popular.

>Wow, this machine really was bare bones:
>http://www.netaffilia.com/ad/electronics/frys/i/2006/10/27/20379.html
>
>

Heh - that's a fine system, other than the memory and CPU (and possibly
the onboard video ;) )

>Just 2 yrs ago it was selling for $129 (I've put a fresh XP install on
>it instead of Linux).
>
>

That was very cheap 2 years ago. I don't think you can buy a barebones
PC for that little today. (unless you get a very good deal)

- Steve