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The New Nvidia 6800 Ultra DDL Graphics Card
Dr. q00p writes "Since Apple doesn't offer much information on the new Nvidia 6800 Ultra DDL graphics card (and NVIDIA even less) which is required to drive the new 30-inch Cinema HD Display the readers of Slashdot might be interested to read a reply from Ujesh Desai, Nvidia's General Manager of Desktop GPUs, to a series of questions from Accelerate Your Mac."
Q & A with Nvidia on the Mac
Nvidia 6800 Ultra DDL Graphics card
Posted: 7/20/2004
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 been outstanding.
* 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 perf
Nope, they should each show up as a single monitor.
The "dual-link" label is misleading, it's mearly an update to the DVI standard (like DVI-I, DVI-A, etc) too allow for more data.
There was actually a really great, informative article about the 6800 on Tom's Hardware a few weeks ago.
"NVIDIA has seemingly pulled out all stops in an attempt to deliver cutting edge graphics with its GeForce 6800 Ultra. After gamers for too long have had to be content with mere incremental improvements to graphics performance, NVIDIA new card delivers a performance jump not seen for a long time. The device is also solidly engineered as well as insanely fast."
Argh. No, it's not. There's 2 (two) dual-link DVI ports, each of which can drive 1 (one) 30 inch monitor. Take a look at the pictures from WWDC where they had a G5 driving two of those monitors.
Since Sun uses OF as well, I wonder if the same card could be used for Macs and Sun workstations.
PCI and AGP are both specified to be little endian regardless of platform.
I've had this sig for three days.
The 30" monitors from Apple have a resolution that cannot be fed by a single-link DVI connection. So they use dual-link DVI. Both single-link and dual-link are part of the DVI 1.0 standard, nothing Apple specific about them.
The difference between single-link and dual-link is how many of the pins in the connector is used for transmitting data, in a nut shell 12 pins for the former and 24 pins for the later.
Apple is using DVI-D (digital only) DVI connectors with a dual-link pin out for the 30" display. So one dual-link DVI-D connection is capable of driving one 30" display. The 6800 adapter used for these displays provides two dual-link DVI-D outputs, so one adapter can drive two 30" displays.
As a reference...
DVI connector type summary
DVI 1.0 specification (PDF)