Mac Pro Octo DVI to Video Adapter problems

Discussion in 'Mac Pro' started by roven97, Sep 4, 2008.

  1. roven97 macrumors newbie

    Sep 4, 2008
    Hi all. I have the new Mac Pro Octo (mar '08) with the NVIDIA GFORCE 8800 GT card. I cannot find anywhere what may be wrong. Only on the Apple Website for the adapter that the only Mac Pro it works with is the Mac Pro (with ATI X1900 XT). However, both tech support and Apple's Store staff said this would work, prior to buying it. Well, my computer does not recognize the TV monitor hooked up via S-Video. I've powered everything down, restarted, unplugged and replugged in both orders, and switched inputs on the TV and receiver both. Nothing.

    Any one know if this does or does not work with this computer???

  2. roven97 thread starter macrumors newbie

    Sep 4, 2008
    Never mind. Found this out via Apples own website. Thanks APPLE TECH SUPPORT and STORE STAFF for getting me to buy a useless cable!

    Mac Pro Computers (January 2008)

    The Mac Pro computers with Quad-Core Intel Xeon 5400 Series microprocessors were introduced in January 2008. The Mac Pro’s graphics subsystem interfaces to the North Bridge via a 16-lane PCIe 2.0 bus. For information on the PCI Express graphics support and expansion, refer to PCI Developer Note.

    The following sections describe the Mac Pro’s graphics subsystem.
    Graphics Cards

    Supported graphics cards have dual-link DVI connectors, supporting 30-inch Apple Cinema HD Displays on both ports.

    For information on video memory, power, and features refer to Table 1.

    All of the supported graphics cards support dual displays in either extended desktop or video mirroring mode; for more detail, see “External Display Modes.”
    Table 1 Supported Graphics Cards

    Graphics card

    Video SDRAM

    Power usage

    ATI Radeon HD 2600 XT (standard)

    256 MB (GDDR3)

    50 W

    NVIDIA GeForce 8800GT (configure to order)

    512 MB (GDDR3)

    110 W

    NVIDIA Quadro FX 5600 (configure to order)

    1536 MB (GDDR3)

    175 W

    The GeForce 8800GT graphics card requires that a booster cable be connected from the PCI slot to the auxiliary power connector. The Quadro FX 5600 graphics card requires two booster cables be connected from the PCI slot to the auxiliary power connector. For additional information, refer to the PCI Developer Note.

    The Mac Pro supports the 20-inch Apple Cinema Display at a resolution of 1680 x 1050, the 23-inch Apple Cinema HD Display at a resolution of 1920 x 1200, and the 30-inch Apple Cinema HD Display at a resolution of 2560 x 1600. All ports support a maximum resolution of 2048 x 1536 at 32-bit with 85 Hz refresh rate. Multiple PCI Express graphics cards can support three or more displays.

    The table below lists the displays supported by port 1 and port 2.
    Table 2 Port 1 and Port 2 support

    Graphics card

    Port 1

    Port 2

    Radeon HD 2600 XT

    20”, 23”, 30” Apple displays

    20”, 23”, 30” Apple displays, DVI to Video Adapter

    GeForce 8800GT

    20”, 23”, 30” Apple displays

    20”, 23”, 30” Apple displays

    Quadro FX 5600

    20”, 23”, 30” Apple displays

    20”, 23”, 30” Apple displays

    For information on video ports, see “Video Monitor Ports.” For information on PCI Express expansion slots, refer to PCI Developer Note.
    Video Monitor Ports

    The Mac Pro has a DVI connector for an external video monitor. For a description of the DVI connector, refer to Figure 4 and Table 30.

    The graphics data sent to the digital monitor use transition minimized differential signaling (TMDS). TMDS uses an encoding algorithm to convert bytes of graphics data into characters that are transition-minimized to reduce electromagnetic interference (EMI) with copper cables and DC balanced for transmission over fiber optic cables. The TMDS algorithm also provides robust clock recovery for greater skew tolerance with longer cables or low-cost short cables.

    Note: The Mac Pro computer includes a DVI to VGA Adapter.

    DVI to Video Adapter

    The Radeon HD 2600 XT graphics card supports an optional DVI to S-video/composite adapter that provides S-video and composite output to a PAL or NTSC video monitor or VCR. When a display is connected by way of the video adapter, the computer detects the type of adapter and enables the composite and S-video outputs. The settings for the resolutions and standards (NTSC or PAL) are then selectable in the Display pane in System Preferences.

    Note: The DVI to Video Adapter does not come packaged with the Mac Pro computer and must be purchased separately.

    The video output connector is a 7-pin S-video connector. Figure 5 shows the arrangement of the pins and Table 31 shows the pin assignments on the composite out and S-video connector.

    The Mac Pro computer provides video output at picture sizes and frame rates compatible with the NTSC and PAL standards; the picture sizes are listed in Table 32. Those picture sizes produce under-scanned displays on standard monitors.
  3. nanofrog macrumors G4

    May 6, 2008
    Perhaps you could return it, or try to sell it. :eek:
    Not much money spent, but aggravating nonetheless. ;)
  4. chapinbk macrumors member

    Jul 12, 2008
    mac pro, geforce 8800 gt, apple dvi to video adapter kit

    Hi roven97,

    I see that you did not provide any contact information at, so I hope this forum post is forwarded to you!

    I'm posting in response to your thread: "Well, my computer does not recognize the TV monitor hooked up via S-Video. I've powered everything down, restarted, unplugged and replugged in both orders, and switched inputs on the TV and receiver both. Nothing."

    I have the same exact issue, and have spoken with tech. reps from both Nvidia, and Apple about it. The Nvidia tech rep was very helpful; He confirmed a list of other products that should work as an alternative to the Apple adapter, but encouraged me to contact Apple tech support, since he was confident the Apple adapter should work as well. Apple tech support was also helpful, but couldn't provide a solution. What he told me is that some older TVs don't properly accept a computer display signal (which seems wrong to me, since an analog signal, like the one generated by the Apple adapter -- s-video OR composite -- shouldn't require digital feedback from the monitor since it's analog!!). My TV is a 20" Sony Trinitron, with s-video and composite inputs.

    Have you had any luck resolving this issue? I would appreciate any help you can offer!

    -chapinbk (just a shmo trying to avoid the purchase of an apple tv :p )
  5. roven97 thread starter macrumors newbie

    Sep 4, 2008
    Yep, they are forwarded to me!

    See my second post. I found in the manual that the NVidia card doesn't support video out. After talking with Apple about it, they suggested that I install a second video card (the Radeon card). Nice.

    Oh well. Also a guy who didn't want to get an Apple TV, since I still don't have a HDTV!!!
  6. chapinbk macrumors member

    Jul 12, 2008

    I was afraid of that :/ Interestingly, MY GeForce 8800 GT for Mac manual states explicitly, beneath the "Connecting Your Display" heading, that "You can connect a television, DVD, DVR, or other external video device with the Apple DVI-to-Video Adapter...using DVI port 2 (not 1)." The manual provides a direct link to the apple store, to purchase the adapter. Crazy, huh? Of course, the information from your post -- -- DOES clear things up.

    I'm glad to hear that you went ahead and bought an ATI card to solve the problem. I'm tempted to do the same thing. The irony is, of course, that I sold my ATI Radeon x1900 on E-bay, when I "upgraded" to the Nvidia Geforce 8800 GT for Mac -- though the ATI card was actually a better performer for SOME graphics applications, and more feature rich too apparently, it was REALLY noisy. Ultimately, I was willing to sacrifice some features/performance for a quiet office, haha.

    I think what I may do instead, since I may very well upgrade my puny 20" TV to something HD soon enuf anyway, at which point a DVI-->HDMI solution will be serviceable, is buy a converter like this one: It's not quite as inexpensive as the Apple adapter, and a little more power hungry (USB powered), but the Nvidia guy was convinced that it was a good alternative solution.

    Thanks for your response!

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