[lug] RH 7.1: Multiple problems

[John Karns]

On Tue, 3 Apr 2001, Scott A. Herod said:

>mohan kumar wrote:
>> 
>> --- "Scott A. Herod" <herod at interact-tv.com> wrote:
>> >
>> > 3) XFree86 doc says that my SiS 620 AGP is supported
>> > but it
>> > does not appear to be.  Anyone have a 620 working
>> > with X86 4.0.2?
>> 
>> one of our linux distributions here in india comes
>> with a suse XF86_SVGA server and it works well with
>> sis 620.
>> 
>> im not sure if it would work with RH7.1 but would be
>> worth trying...
>> 
>
>Thanks for the note.  It seems strange to me that I am
>having problems since I have not read about any.  I suspect
>that I am doing something wrong.
>
>I ended up bringing in an old PCI graphics card that I
>had a home ( the work machine has pci slots but of the 620 is
>on the motherboard and uses the agp connection ).  So,
>I'm up and running and probably won't mess with it again.
>
>( On a separate note, I got an ATI AGP card for home to replace
>the PCI card I brought into work.  It came up nicely
>with RH 6.2 but I can't get it to work with NT.  The machine
>is dual boot.  Rather ironic, I thought. )

I think not so strange - the SiS chips have been particularly troublesome
since their appearance.  They are something akin to the Winmodems, in that
they are somewhat deficient on hardware and borrow hardware resouces from
the mainboard, most notably the video memory.  AFAIK, they don't really
have their own memory, but instead "borrow" from the MB RAM by
"partitioning" it.  I tried about 2 yrs ago to get one of them to work
with Linux / X but finally gave up.  OTOH, there are many people who have
managed to get them to work, but I think the larger consensus has been to
look for other alternatives.  Not to discourage you, but I make it a point
to avoid them.  Sometimes even when one is able to actually get one of
these to work, performance can be poor.

I also have encountered problems with them in several W9x machines.  
Specifically, when displaying added effects such as vertical or diagonal
sliding movement to MS Powerpoint slide presentations, the animation was
extremely slow.  We were using 350 and 500 MHz MB's, so it wasn't as if
the machine was very deficient in speed.  We ended up using more
conventionally designed cards to avoid the problem, although there are
some tricks to optimizing their performance, such as minimizing the video
memory aperture in the system BIOS.  This sped up the animation
significantly, although it was still noticably slower than the
conventional cards.

----------------------------------------------------------------------
John Karns                                              jkarns at csd.net