Just wanted to quickly discuss my experience using this card for the past couple days so people know exactly what they are getting.
Setup
I bought this card on eBay for $60. I think I overpaid, but it was this or buying an original G5 Retail X1900 for $100 which I personally felt wasn't worth it. I got the Sapphire variant of the X1950 XT with the robot lady on the front of the card. I would not recommend getting this card if you plan on having more PCIe cards in your case as this is a two slot card, but pretty much all of the X1900 GTs are gone. Probably snapped up by various Mac enthusiasts and it's hard to say if it was a popular card back then. I do not think it was ever an OEM card so examples are a little rare.
I followed this guide for flashing the card. Worked first try just fine, no problem. I used a native BIOS machine lended to me from a friend (an HP z800). You can indeed just have the ATI card provide graphics output and you will be good to go. No need to use a basic VGA adapter alongside the card in FreeDOS.
I plugged the card in and I was off.
Practical Performance
The first thing I noticed is that the desktop UI was not noticeably faster than the 6600, but having no flickering graphics on start up is already a huge win for me making the card worth the cost. There is one major exception to this though. On Leopard (and Snow Leopard) if you have an application folder on your dock then opening it will play the animation smoothly after a brief lag after clicking on the folder depending on how many icons reside there. This makes this particular feature a little more useful which is nice.
Another big practical advantage is the ATI Displays menu. I really only care for one feature which is the ability to display previously unavailable resolutions for your display including scaled and interlaced. This can make working on an older TV set pretty nice just in case Mac OS X didn't previously support that resolution. You can also rotate the displays in this menu and set OpenGL performance overrides which IDK if they truly impact performance much at all. It would only be useful for stubborn games that do not properly turn on some features in the menu.
Doom 3 was the only gaming test that I really sat down and tried to gauge the card's performance with. At 1280x1024 on High settings it ran at 60 fps and dropped to 30-40 during certain gunfights with lots of particle effects. I am pretty satisfied with this result. The most intensive game on this system that matters is Quake 4 with the Q4Max mod which I cannot test because I don't have a valid serial key, so I can't gauge how well it performs with multicore rendering on.
A particular bug I noticed is in Lego Star Wars 1 Shadow Maps would tank performance heavily. Turning these off let the game run smoothly even at 1600x1200.
Quake 3 runs with no frame drops below 60. I don't know how to speed demo it so it remains that my experience tells me this is good. I cannot for the life of me figure out why mouse acceleration isn't fixable on this machine though.
Aperture 2 loaded thumbnails slightly faster and let me start cropping about as fast as the 6600 would. Some visual effects, however, applied much faster in Aperture and Photoshop CS4.
Blender 2.63a worked wonderfully on this machine but it didn't have access to GPU-accelerated rendering so I'll not go into more detail. Quad G5 handles 3D CAD fine, who knew...
Synthetic Benchmarks
I ran all the typical benchmarks. Xbench, Geekbench, and OpenMark were my choices. This is pretty informal testing.
Xbench 1.3: Comparing the 6600 and the 1900 XT Quad, the 1900 XT Quad easily pulls ahead by 30 overall points (170 vs. 140). The Quad improves in only one area by any significant margin, which is the OpenGL Squares test where it had a 50 point advantage over the 6600. Quartz Graphics shockingly didn't improve at all.
Geekbench 2.2.7: This didn't test the GPU so both runs remained at 3400 points or so.
OpenMark: I didn't test this on the 6600, but I could render well over a million triangles and the frame rate was still above 60fps. The 3D performance is obviously better on the X1950 XT.
What does a new GPU get you then?
GPU acceleration by 2006 was very rare in non-3D applications. It exists in Core Image stuff and some Photoshop filters like Liquify are GPU-accelerated I believe, but really not much else. You will get a better performing Leopard UI which for some that matters a fair bit. You will also get tremendously better 3D performance in Maya, Blender, video games, and any other 3D CAD application. What this doesn't effect is general system performance so apps like QuickTime Player and Pages and web browsers will be no faster.
The deal with QuickTime Player is interesting because it suggests that there's no video decoding support on this GPU that is significantly better than stock. There is an API for hardware-accelerated video encoding called ATI Avivo, but who knows if this was ever implemented in Mac OS X. I wouldn't be shocked if it was but only for the Mac Pro cards.
I would say if you do not play games just stick with the stock card, but for me this was a worthy upgrade.
Setup
I bought this card on eBay for $60. I think I overpaid, but it was this or buying an original G5 Retail X1900 for $100 which I personally felt wasn't worth it. I got the Sapphire variant of the X1950 XT with the robot lady on the front of the card. I would not recommend getting this card if you plan on having more PCIe cards in your case as this is a two slot card, but pretty much all of the X1900 GTs are gone. Probably snapped up by various Mac enthusiasts and it's hard to say if it was a popular card back then. I do not think it was ever an OEM card so examples are a little rare.
I followed this guide for flashing the card. Worked first try just fine, no problem. I used a native BIOS machine lended to me from a friend (an HP z800). You can indeed just have the ATI card provide graphics output and you will be good to go. No need to use a basic VGA adapter alongside the card in FreeDOS.
I plugged the card in and I was off.
Practical Performance
The first thing I noticed is that the desktop UI was not noticeably faster than the 6600, but having no flickering graphics on start up is already a huge win for me making the card worth the cost. There is one major exception to this though. On Leopard (and Snow Leopard) if you have an application folder on your dock then opening it will play the animation smoothly after a brief lag after clicking on the folder depending on how many icons reside there. This makes this particular feature a little more useful which is nice.
Another big practical advantage is the ATI Displays menu. I really only care for one feature which is the ability to display previously unavailable resolutions for your display including scaled and interlaced. This can make working on an older TV set pretty nice just in case Mac OS X didn't previously support that resolution. You can also rotate the displays in this menu and set OpenGL performance overrides which IDK if they truly impact performance much at all. It would only be useful for stubborn games that do not properly turn on some features in the menu.
Doom 3 was the only gaming test that I really sat down and tried to gauge the card's performance with. At 1280x1024 on High settings it ran at 60 fps and dropped to 30-40 during certain gunfights with lots of particle effects. I am pretty satisfied with this result. The most intensive game on this system that matters is Quake 4 with the Q4Max mod which I cannot test because I don't have a valid serial key, so I can't gauge how well it performs with multicore rendering on.
A particular bug I noticed is in Lego Star Wars 1 Shadow Maps would tank performance heavily. Turning these off let the game run smoothly even at 1600x1200.
Quake 3 runs with no frame drops below 60. I don't know how to speed demo it so it remains that my experience tells me this is good. I cannot for the life of me figure out why mouse acceleration isn't fixable on this machine though.
Aperture 2 loaded thumbnails slightly faster and let me start cropping about as fast as the 6600 would. Some visual effects, however, applied much faster in Aperture and Photoshop CS4.
Blender 2.63a worked wonderfully on this machine but it didn't have access to GPU-accelerated rendering so I'll not go into more detail. Quad G5 handles 3D CAD fine, who knew...
Synthetic Benchmarks
I ran all the typical benchmarks. Xbench, Geekbench, and OpenMark were my choices. This is pretty informal testing.
Xbench 1.3: Comparing the 6600 and the 1900 XT Quad, the 1900 XT Quad easily pulls ahead by 30 overall points (170 vs. 140). The Quad improves in only one area by any significant margin, which is the OpenGL Squares test where it had a 50 point advantage over the 6600. Quartz Graphics shockingly didn't improve at all.
Geekbench 2.2.7: This didn't test the GPU so both runs remained at 3400 points or so.
OpenMark: I didn't test this on the 6600, but I could render well over a million triangles and the frame rate was still above 60fps. The 3D performance is obviously better on the X1950 XT.
What does a new GPU get you then?
GPU acceleration by 2006 was very rare in non-3D applications. It exists in Core Image stuff and some Photoshop filters like Liquify are GPU-accelerated I believe, but really not much else. You will get a better performing Leopard UI which for some that matters a fair bit. You will also get tremendously better 3D performance in Maya, Blender, video games, and any other 3D CAD application. What this doesn't effect is general system performance so apps like QuickTime Player and Pages and web browsers will be no faster.
The deal with QuickTime Player is interesting because it suggests that there's no video decoding support on this GPU that is significantly better than stock. There is an API for hardware-accelerated video encoding called ATI Avivo, but who knows if this was ever implemented in Mac OS X. I wouldn't be shocked if it was but only for the Mac Pro cards.
I would say if you do not play games just stick with the stock card, but for me this was a worthy upgrade.
