slow performance for schematic composer (on VNC) for large grid spacing or when it is turned off.

Here is a problem that I've kind of figured out recently. Whenever I
turn off the grid on any schematic (even small designs), schematic
refreshes or zooming operations on a vnc session (key: F6) become very
slow. Quite often every 5th or 6th zoom, I'll need to wait for about
10seconds for the cadence schematic to get updated. If I turn the grid
back on, it gets fast again. 24-bit & 8-bit color performance on the
server both show the same problem. I also changed # of colors on the
vnc viewer (Real VNC 4.1.1), different types of encoding etc. on
windows XP,and it didn't make any difference.

The slow performance happens when I increase the grid size to something
like 6.x + (I tried to do this to make the grid less obvious, since I
don't like looking at the grid), along with making the "multiple" field
1, performance starts to degrade.

Any ideas if this is something to do with cadence/vnc OR graphics
hardware? Any possible workarounds other than keeping the grid on? Just
a minor peeve! I hope others can replicate this. Cadence version 5.0.33
running on RHEL 2.1....

thanks,
Jose

 

Have you tried using:

icfb -noblink

Or typing in the CIW:

hiEnableBlink(nil)

Regards,

Andrew.

 

Yes, I tried both and made sure that blink was off using
hiIsBlinkEnabled(). Didn't make a difference. This along with the
experments with 8-bit color leads me to suspect that color depth is not
the issue here...

 

I suspect it's something to do with the driver you're using for your graphics
card - perhaps it does not have the settings optimized?

Anyway, I'd suggest contacting custmer support, with details of the graphics
card and driver that is being used (in the XF86Config file, if you're using
XFree86).

Andrew.

 

Thanks for the suggestion, Andrew.

I kinda took a quick look @ the driver file in the X11 dir. Without
knowing too much about X, I wonder how one driver file on an X/VNC
compute server would be able to cater to multiple VNC sessions running
on multiple monitors for multiple users. Anyway something that I'll
need to figure out.

I already contacted Cadence support and they suggested that it was most
probably a VNC issue. Anyway, since I have a work-around (grids ON),
I'll just go with that.

Merci,
Jose