On Tue, 14 Jan 2003 07:51:10 -0500 (EST), Vladimir Dergachev wrote: > >One thing I don't understand about this is that this is an integrated >graphics chipset, right ? I.e. it uses part of system RAM for video RAM. >There is no code in radeon driver to deal with this yet.
And there doesn't need to be. The allocation of video RAM from system RAM is done by the BIOS very early in boot time. The physical address of the video RAM gets stuffed into the PCI BAR register. The driver doesn't know or care whether that address is physically on an AGP bus, or in system RAM. The Savage driver is an example. The Savage/IX uses shared memory, whereas the Savage/MX has its own separate VRAM. The driver doesn't care at all. Interesting side note: I had a fellow this week report to me that his disk performance goes down by HALF when he switches from 1024x768 60Hz depth 8 to 1280x1024 85Hz depth 24. He has a shared memory system, and the simple act of refreshing the screen at the higher resolution puts a constant 450MB/sec load on his processor bus. Depending on the speed of your front-side bus, that could be from 1/3 to 3/4 of your north bridge throughput. -- - Tim Roberts, [EMAIL PROTECTED] Providenza & Boekelheide, Inc. _______________________________________________ Devel mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/devel
