WQUXGA a.k.a. OMGWTF – IBM T221 3840×2400 204dpi Monitor – Part 3: ATI vs. Nvidia

It is at times like this that I get to fully consider just how bad a decision it was to jump ship from ATI to Nvidia when it came to graphics cards. But now that sense has been forced back upon me, I will hopefully not consider such madness again for the best part of the next decade.

Due to the ATI drivers being fundamentally unable to handle the T221 reliably, I bit the bullet and decided to put my old 8800GT card back in. The first WTF came about when it transpired that ATI drivers cannot be uninstalled from Windows XP using their bundled uninstaller in Safe or VGA modes. This is quite bad when you consider that it could be the ATI drivers that are making the machine not boot into normal mode. Credit to it, though, the ATI uninstaller was not too bad once I ran it in normal mode, and after using it to remove all ATI software and uninstalling the ATI devices in Device Manager, there wasn’t enough left to cause problem on the next reboot, during which the machine contained an Nvidia card. Everything booted up fine, and after a quick run of the Auslogics Registry Cleaner (just to make sure – easily the best registry cleaner I have used to date), everything was ready for the installation of Nvidia drivers. Everything went quite painlessly, and a reboot later I had the T221 configured for 2x1920x2400@20Hz mode. The only thing that didn’t come up perfectly by default is that I had to add the 1920×2400@20Hz mode in Nvidia Control Panel (click the Customize button).

By this point, the superior features of Nvidia were already becoming apparent:

  • Text and low-resolution mode anti-aliasing in firmware – such modes look vastly better than on ATI hardware).
  • Until the driver enables the secondary port, it remains disabled. This is really nice on the T221 because it means you don’t get the same thing on the screen twice during the BIOS POST and early stages of the boot process. I can imagine this also being annoying on a multi-head setup.
  • The primary port wasn’t switching for no apparent reason in Windows with multiple screens plugged in.
  • Best of all – Windows XP drivers Just Work ™. They don’t forget their settings between reboots.
  • No tearing down the middle of the screen where the two halves meet. With the ATI card, the mouse couldn’t be drawn on both halves at the same time. In the middle, you could make it virtually disappear, Not a big deal, but yet another example of general bugginess. Also, in games the tearing along the same line disappeared (I always run with vsync forced to on, and it was still visible from time to time with the ATI card).

Just the properly working drivers would have easily convinced me of the error of my recent ways, but all the other niceties really make for a positive difference to the experience.

After I got Windows working (it only took 20 minutes, after giving up on ATI after wasting a whole day on getting it to work properly and remember the settings between reboots), it was time to get things working in Linux. The first thing that jumped out at me about this part of the exercise is just how much better ATI’s Linux drivers are compared to their Windows drivers. It is obvious that they are actually being developed by somebody competent. Unlike the Windows drivers, the Linux drivers worked out of the box, and the only unusual thing that I needed to do was to make sure Fake Xinerama was configured and preloaded. Removing them was a simple case of:

# rpm -e fglrx

Simple, efficient, reliable. Seems ATI‘s Windows driver team have a lot to learn from their Linux driver team.

The machine came up fine with the nouveau drivers loaded, but I wanted to get Nvidia’s binary drivers working. The experience here was a little more problematic than it had been with the ATI drivers. The nvidia-xconfig and nvidia-settings utilities weren’t as intuitive as the ATI configuration utility, and the setup suffered from a particularly annoying problem where GPU scaling would default to on. This resulted in the screen mode being left stretched and unusable, but sometimes just starting the nvidia-settings program would fix some of it. In the end I just gave up on it and wrote my own xorg.conf according to the documentation – and that worked perfectly. You may want to set the following environment variable to force vsync in GL modes (e.g. for mplayer’s GL output)

# export __GL_SYNC_TO_VBLANK=1

This ensured there was no tearing visible during video playback.

One thing worth noting is that Nvidia drivers bring their own Xinerama layer with them, so the Xorg Xinerama should be disabled. There is also an option for faking the Xinerama information (NoTwinViewXineramaInfo), so no need for Fake Xinerama, either.

In conclusion, it is quite clear that Nvidia win hands down in terms of features and user experience, especially on Windows, due to their more stable drivers are more intuitive configuration utilities. The story is different on Linux – I would put ATI slightly ahead on that platform, at least in terms of configuration utilities. Having to use Fake Xinerama isn’t a big deal for the technically minded. Even on Linux, however, in terms of the overall outcome and the end experience, I feel Nvidia still come out ahead, since ATI drivers still occasionally produce visible tearing when playing back high definition video.

All this made me think about what is the most important thing about a product such as graphics cards. In the end it is not just about performance. Performance is only a part of the overall package. What I find is that the most important thing about a product is the whole experience of configuring it and using it. How easy is it to get to working under edge case conditions? How reliable is it – once it is working does it stay working? Are there any experience ruining artifacts such as tearing visible in applications, even with vsync enabled? These sorts of things along with the crowning touches such as anti-aliasing of low resolution modes and only having one active video output until the drivers specifically enable the others are what really impacts the experience. And based on my experience of Nvidia and ATI cards over the past few years, I hope somebody talks some sense to me if I consider an ATI product again – except perhaps if their FireGL team starts writing their Windows drivers.

1 thought on “WQUXGA a.k.a. OMGWTF – IBM T221 3840×2400 204dpi Monitor – Part 3: ATI vs. Nvidia

  1. Pingback: WQUXGA – IBM T221 3840×2400 204dpi Monitor – Part 6: Regressing Drivers and Xen - Altechnative

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