Core images unabled, why Apple ?
Reply 21 of 22
August 28, 2005 9:46PM
Originally posted by BeigeUser
My card is a 9600. That confirms my theory that a 9800 is needed for a smooth dual-monitor setup. How much VRAM does your 9800 have?
Standard 128 mb 9800 pro.
Reply 22 of 22
August 29, 2005 4:37AM
Originally posted by Chucker
Alright, I'll explain.
Let's assume for a moment that PowerPC-based Macs, as in every Mac since late 1994, were to use something compatibe with the traditional x86 BIOS. That's entirely possible; it would require some adjustments, but that's it. Today's PCs don't exactly use the original BIOS of the late 70s / early 80s anyway; they just use something that's compatible on the outside.
So, if that were true, then your average PC graphics card would work on a Mac. It would require a driver, it wouldn't immediately have the full resolution when you boot (instead, it would have some crippled resolution of 512x384 or whathaveyou) and it would have other issues that graphics card have when they come with a BIOS ROM. But it would work. So why doesn't Apple do that? Because they want something better. That better thing, as of the first PowerPC-based Mac, is OpenFirmware. Before PowerPC, Apple used their own type of ROM, which was in no way similar to the BIOS either, but it was very limited compared to OpenFirmware.
(Someone pedantic is going to note that the first generations of PowerPCs, before PCI was introduced, didn't use OpenFirmware, and that every New World Mac, since the first iMac, actually uses a vastly more enhanced OpenFirmware, but let's leave that out for this argument.)
OpenFirmware introduced many niceties to the architecture of a Mac, the important graphics card-related one being that
the graphics card provides the driver
. That's right. The driver is right there on the ROM. And it's not, like on a PC card, a driver for a craptacular resolution at 256 colors or less, no, it offers full support for, say, 1920x1080 at 24-bit color.
Right from the moment you boot your computer.
That's why, when you boot a PC, you start at a low resolution, then once Windows or whatever OS you use has loaded the proper drivers, it switches to a better resolution. On a Mac, from the moment you actually see graphics output (e.g. the grey Apple), you have the full resolution.
However, this is a
of OpenFirmware. Graphics cards
provide a proper driver on their ROM. ATi has, it appears, finally figured out how to provide a ROM for both OpenFirmware and BIOS.
It is my understanding that EFI provides similar features to OpenFirmware, maybe even more advanced to some degree. It is unlikely for Apple to switch to BIOS during the x86 move, despite the fact that their developer machine is in fact BIOS-based. Whether they use EFI or OpenFirmware, they will probably end up with a system that
require you to use a Mac-specific video card, unless ATi uses its hybrid technique on all graphics cards from now on and/or licenses that to nVidia (or they figure it out as well).
Again: the CPU has nothing to do with it. [/B]
thankyou for explanation!!!