View Full Version : Driver problem for 6800 Geforce Ultras in SLi Mode and Apple 30 inch cinema display

06-09-05, 06:15 PM

Im running a pair of 6800 Geforce Ultras in SLi mode on an Asus A8N-SLi Deluxe motherboard. Im using Windows XP media center edition. All the latest updates have been installed for XP.

I bought an Apple 30 inch cinema display. Its very pretty and I like it a lot BUT (and its really frustrating!)

The problem is that I cant seem to get windows to see a screen resolution above 1280 X 800. It doesnt see the Apple monitor it just reports a "plug and play" monitor which cant go above 1280 X 800.

I cant find a specific windows XP driver for the Apple display.

Im using version of the Nvidia drivers.

Has anyone else had this problem please and if so please how do you fix it?

Many many thanks.


06-09-05, 06:53 PM
Try looking here. http://www.nvnews.net/vbulletin/showthread.php?t=51106&highlight=Custom+Resolutions

There are also some other threads on that but the above link was one of the later ones.

06-10-05, 01:46 AM
doesn't the apple 30" use dual DVI inputs?

SLI does not work with dual DVI outputs... the sad news is you can't use the SLI with the apple 30" display..

this has been my only gripe about SLI, the fact you can only use 1 output while in SLI mode..

my recommendation would be to try and return one of the 6800's for your $$ back..

06-10-05, 12:39 PM
doesn't the apple 30" use dual DVI inputs?

SLI does not work with dual DVI outputs... the sad news is you can't use the SLI with the apple 30" display..

my recommendation would be to try and return one of the 6800's for your $$ back..

Yes the cinema display requires dual-link DVI. There are very few manufacturers who make dual link cards capabale of SLI. You can get quadro's or I believe the Asus Ultra's are dual-link capable.

What Brand cards did you get?

06-10-05, 02:19 PM
Ive taken out the second Nvidia Geforce 6800 Ultra from my computer so Im not in SLi mode anymore. Ive disabled SLi on the Asus motherboard. Removed the Nvidia drivers and reloaded them. BUT the resolution is still stuck on 1280 X 800. If I try and manually set the resolution at 2560 X 1600 (or indeed at any other level) the screen becomes garbledand I have to start windows in safe mode and uninstall the card and start from scratch.

I spoke to Apple who assure me it should work. But it doesnt.

To recap: Asus A8N-SLi Deluxe motherboard. Windows XP media center edition. Nvidia Geforce 6800 Ultra. Apple 30 inch display. Resolution stuck at 1280 X 800.

What am I doing wrong?

Sigh. Really really deep sigh.

06-10-05, 02:45 PM
what brand of 6800 Ultra are you using?

i am reading up on the Apple 30" and it appears that the 6800 Ultra brand has to be specifically a DDL (Dual DVI Link)

you may find this thread more helpful


06-10-05, 03:31 PM
Thanks very much.

Im using an XFX GF 6800 Ultra 256MB Dual DVI.

The link to their product page is


Im not sure if it is DDL (Dual DVI link) but it has got two DVI output sockets on the card. Is that what it means?

Many thanks.

06-10-05, 04:13 PM
two DVI ports != Dual DVI link..

Dual DVI link is a way to use both DVI outputs to 'drive' a single display..

06-10-05, 05:08 PM
two DVI ports != Dual DVI link..

Dual DVI link is a way to use both DVI outputs to 'drive' a single display..

that is what i thought at first, but after reading about it it appears the DDL is different..

without DDL the max resolution you get with the Apple is the 1280x800..

a DDL equiped card can do the native max res for it..

here is what i have been able to find out..

Put simply: The creators of the DVI standard were pretty smart. Turns out that mosy graphics cards/displays are single-link: they only use 12 of the 24 pins in the DVI connection, but the dual-link uses all 24 and therefore has twice the throughput.

I should remind, that current PC-based 6800's are not DDL compatible yet, but they should be soon -- once DDL compatible cards arrive on the PC, it's not a problem.

06-11-05, 05:51 AM
Thanks for all your input. It is very much appreciated. I am using a XFX Geforce 6800 Ultra DDR3 Dual DVI TV PCI-E (I was using 2 in SLi mode on my Asus A8N-SLi Deluxe motherboard but I was worried that the SLi bit might be confusing the issue).

According to SFX http://www.xfxforce.com/web/product...spa?seriesId=41

their GF 6800 Ultra's output is Dual DVi. They say on their web site "Dual-Link DVI Support Able to drive the industry's largest and highest resolution flat-panel displays."

I dont know what Im doing wrong. The XFX code for the card is PV-T45-UDF7. Its all bit confusing.


06-12-05, 01:50 PM
Kene, you have a couple of roads to travel..

i would first contact XFX via email or however and confirm that the model and revision (the revision number maybe important) is infact dual link DVI..

if its possible to return the 6800Ultra's that is another route to go and then contact Apple and specifically ask them which brand of 6800Ultra they have tested it with..

the more i look for 6800's with dual link for PC the more all i see in the specifications are..

Dual Single-Link DVI...

it seems that the new Geforce 512MB's are coming standard with dual-link DVI..

BFG's 6800 Ultra 512 Seems to have it..

from the firingsquad website..

Thankfully, BFG had the foresight to employ two, dual-link DVI connectors, each of which supports resolutions up to 2048x1536 at 85Hz. You’ll get away with up to 1920x 1080 at 60 Hz using the single-link port featured on 256MB Ultra cards. But if you really want to go big, Apple’s 30-inch Cinema HD display, for instance, requires a dual-link DVI output for operation

my recommendation would be..

return your XFX if you can and go buy a single BFG 512MB...


if you really think the XFX has dual-link i would contact them..

you h ave to be careful though, they list that on the main description page for the Geforce series.. that may be specifically describing their XFX GF6U 512MB

06-12-05, 10:45 PM
Dual DVI is not the same as Dual Link DVI. Dual DVI means that there are two (almost definitely single-link) DVI ports on the back of the card, DDL means that the DVI ports themselves have been electrically doubled to carry twice the information. An Apple 30" can be powered by one DDL DVI port only. A DDL Geforce 6800 Ultra can actually power two 30" displays at full resolution, but a normal one can't power any.