diff -u programs/Xserver/hw/xfree86/drivers/xgi.orig/xgi_opt.c programs/Xserver/hw/xfree86/drivers/xgi/xgi_opt.c
--- programs/Xserver/hw/xfree86/drivers/xgi.orig/xgi_opt.c	2005-04-29 12:26:17.698250588 +0200
+++ programs/Xserver/hw/xfree86/drivers/xgi/xgi_opt.c	2005-04-29 12:29:03.210214965 +0200
@@ -448,6 +448,12 @@
 
     }
 
+    /* 
+     * Disable XV support for XGI Z7 chip
+     */
+    if (PCI_CHIP_XGIXG20 == pXGI->Chipset)
+    	 pXGI->NoXvideo = TRUE;
+
     /* SWCursor
      * HWCursor
      * Chooses whether to use the hardware or software cursor