Shortly after Apple announced the Mac Nvidia 6800 Ultra DDL card for the PowerMac G5s (which is required to drive the 30in Cinema Display), I sent a series of questions to a contact at Nvidia on the card. Yesterday I received the reply from Ujesh Desai, Nvidia's General Manager of Desktop GPUs. Although some questions didn't get as complete an answer as I hoped (often due to the fact Apple controls OEM Mac Nvidia products), I appreciate his taking the time to reply.
* How does the NVIDIA GeForce 6800 Ultra DDL card for the Mac differ from the PC version (i.e. Does the PC version have dual link DVI?)
The GeForce 6800 Ultra DDL card was designed specifically for the Mac to provide two dual-link outputs to support Apple's displays.
* Does the Apple version of the GeForce 6800 Ultra GPU run at the same core/memory clock as the PC version?
The Apple cards run at 400/550, just like the GeForce 6800 Ultra GPU on the PC.
(Note: Some vendor's 6800 cards are clocked higher than the standard/reference design.)
* The GeForce 6800 Ultra for the PC has two Molex power connectors -
does the Mac version source all the power from the G5's AGP pro slot?
(or does it have a aux power connector?)
There is an on-board power connector on the graphics card and the motherboard to provide power, so there is no need for an external power connector from the power supply.
(although the only Mac 6800 photos I've seen are tiny, it appears
there's a stub connector on the card that (I suspect) uses the
ADC (28V or 24V usually) DC power connector on the motherboard that's normally used for ADC display power to provide additional power (regulated down) for the 6800 card. That eliminates the need for Aux. (Molex) P.S. connector(s) like the PC/standard 6800 card versions have.)
* Does the GeForce 6800 Ultra DDL have a low-noise fan?
Yes, the GeForce 6800 Ultra DDL runs very quiet.
* Will there ever be a control panel with 3D/GL/FSAA controls for the
NVIDIA cards on the Mac platform?
(ATI's retail Radeon cards (and OEM models with the 3rd party patch)
have a '3D/GL overrides' feature - which is seen as a big plus by many end users.)
Apple provides all the drivers for NVIDIA-based add-in cards. We supply them with the source code and they provide the final driver.
* Regarding the previous question - if there's no chance of an Apple
supplied NVIDIA card control panel (for advanced features/FSAA, etc.) -
if a 3rd party wanted to do this, can NVIDIA provide some assistance?
Apple is our customer, so if this is something that they requested, then we would support it.
* There's been talk of previous NVIDIA cards taking a bigger than
expected performance hit from using some types of shaders (on the Mac) -
is this a concern with the GeForce 6800 Ultra DDL?
GeForce 6 Series GPUs have the most advanced shading engines on the
market. Compared to previous generation parts, the vertex and pixel
shader engines on GeForce 6 Series GPUs have been completely redesigned
from the ground-up. Pixel Shader performance is 4 to 8 times faster.
Vertex shader performance is twice as fast. Performance numbers have
* Will there updated/new drivers for the GeForce 6800 Ultra?
Yes. Apple provides all the drivers for NVIDIA-based add-in cards.
We supply them with the source code and they provide the final driver.
Apple will control the release schedules for drivers that provide even
more performance, features and image quality enhancements.
* Do you have any idea how performance compares on the Mac between the GeForce 6800 Ultra and the ATI 9800 Pro/XT card?
GeForce 6800 Ultra represents the largest leap forward in graphics performance in our company's history. As expected, they are much faster than previous generation products from ATI. We will let the benchmarks speak for themselves.
(Note: There's no Mac 6800 performance reviews currently as it's not set to ship until late August. (I should have one for tests then.) Nvidia's 6800 reviews page lists many PC site reviews of various models of the 6800 - but most compare performance to the ATI 9800/XT model, not the faster/more advanced X800 series. One review that does have some (PC) 6800 Ultra vs ATI X800 (XT/Platinum models) tests is this article at Anandtech, which in the limited tests run there shows similar performance in Halo and Aquamark. However a more recent article on Doom3 benchmarks (run by ID) show the 6800 cards (Ultra and GT models) delivering higher framerates (esp. in AGP form factor at higher res) than the X800 Platinum edition and X800 Pro. Of course there's no Mac ATI X800 series cards announced yet, although I'd bet they're in the works. (Update - the ATI drivers in 10.3.5 have a reference to the X800 Pro.) The Doom3 benchmarks seemed to have really boosted demand for 6800 cards due to the better OpenGL performance in that game (despite the fact the X800 cards often did better in DirectX games). I wonder if the recent Half-Life 2 engine stress tests showing the X800 series as better performers will turn the tables a bit. (Of course for Mac OS X, OpenGL is used for 3D apps/games and Quartz Extreme.))
* Platforms/drivers aside - how does the GeForce 6800 Ultra compare in design/features to the ATI X800 series?
ATI has spun an old architecture and have done a very good job of squeezing the last bit of untapped performance from it and the drivers. GeForce 6 is a new architecture and we will have a lot more headroom than they will. We always give significant performance increases after we have leveled out the stability of the new architecture. GeForce 6 should continue that trend. Other key differences include:
- We support shader model 3, they do not.
- We support 64-bit floating point blending and filtering, they don't.
- We are the first chip with an onboard video processor
(Note: Some previous ATI cards like their AIW models have shipped with the "Rage Theater" video encoder/decoder chip on the card. It was first intro'd in 1998, and revised I'm sure since then. Of course the current generation of GPUs have more advanced features.)
* This is an old question, but do you think there will ever be a retail Mac NVIDIA card? (i.e. Is the Apple contract an exclusive on the ROM code, etc. - or is there just no interest in PC graphics card mfrs to do a Mac product?)
We sell GPUs, we do not sell add-in cards. Apple has offered stand
alone cards for sale on the Apple store in the past. We plan on
continuing to offer products for the Mac platform through Apple.
(I was trying get an answer if the Apple contract was an exclusive, or if the reason there are no Mac retail Nvidia cards is
that none of the (many) companies that have sold PC Nvidia GPU based cards have any interest in selling a Mac retail product. (i.e. - Has any company approached Nvidia about licensing the mac ROM, etc.) Although Apple has from time to time sold OEM Mac Nvidia cards separately, the selection has been sparse and prices typically high. PC 6800 Ultra cards are currently priced similar to the Mac 6800 Ultra however, but the Mac model only works/fits in a PowerMac G5. And with lots of retail competition, PC versions typically drop in price over time.)
* Normally DVI (DVI-I) port cards have analog pins in the connector so that a DVI->VGA adapter can be used. Can a DVI to VGA adapter be used with the Mac 6800 Ultra DDL DVI ports? (Apple's currently limited info on the card does not mention this capability)
There is no technical reason why a DVI to VGA adapter would not work on this board.
I've wrote contacts at ATI for their comments on future Mac graphics card models such as an X800 based card and replies to any comments above, which I'll add to this page when received.
For previous tests of Mac graphics cards (Mac 9800 Pro retail, OEM 9800, GF4 Ti, etc.), see the graphics card section of the Video topics page.