Video Hardware, Part 3 - The Video Driver
(Page 7 of 12 )
The software driver is an essential, and often problematic, element of a video display subsystem. The driver enables your software to communicate with the video adapter. You can have a video adapter with the fastest processor and the most efficient memory on the market but still have poor video performance because of a badly written driver.
Video drivers generally are designed to support the processor on the video adapter. All video adapters come equipped with drivers the card manufacturer supplies, but often you can use a driver the chipset maker created as well. Sometimes you might find that one of the two provides better performance than the other or resolves a particular problem you are experiencing.
Most manufacturers of video adapters and chipsets maintain Web sites from which you can obtain the latest drivers; drivers for chipset-integrated video are supplied by the system board or system vendor. A driver from the chipset manufacturer can be a useful alternative, but you should always try the adapter manufacturer's driver first. Before purchasing a video adapter, you should check out the manufacturer's site and see whether you can determine how up-to-date the available drivers are. At one time, frequent driver revisions were thought to indicate problems with the hardware, but the greater complexity of today's systems means that driver revisions are a necessity. Even if you are installing a brand-new model of a video adapter, be sure to check for updated drivers on the manufacturer's Web site for best results.
Note -Although most devices work best with the newest drivers, video cards can be a notable exception. Both NVIDIA and ATI now use unified driver designs, creating a single driver installation that can be used across a wide range of graphics chips. However, in some cases, older versions of drivers sometimes work better with older chipsets than the newest drivers do. If you find that system performance or stability, especially in 3D gaming, drops when you upgrade to the newest driver for your 3D graphics card, revert to the older driver.
The video driver also provides the interface you can use to configure the display your adapter produces. On a Windows 9x/Me/2000/XP system, the Display Control Panel identifies the monitor and video adapter installed on your system and enables you to select the color depth and screen resolution you prefer. The driver controls the options that are available for these settings, so you can't choose parameters the hardware doesn't support. For example, the controls would not allow you to select a 1024x768 resolution with 24-bit color if the adapter had only 1MB of memory.
When you click the Advanced button on the Settings page, you see the Properties dialog box for your particular video display adapter. The contents of this dialog box can vary, depending on the driver and the capabilities of the hardware. Typically, on the General page of this dialog box, you can select the size of the fonts (large or small) to use with the resolution you've chosen. Windows 98/Me/2000 (but not Windows XP) also add a control to activate a convenient feature. The Show Settings Icon on Task Bar check box activates a tray icon that enables you to quickly and easily change resolutions and color depths without having to open the Control Panel. This feature is often called QuickRes. The Adapter page displays detailed information about your adapter and the drivers installed on the system, and it enables you to set the Refresh Rate for your display; with Windows XP, you can use the List All Modes button to view and choose the resolution, color depth, and refresh rate with a single click. The Monitor page lets you display and change the monitor's properties and switch monitor drivers if necessary. In Windows XP, you can also select the refresh rate on this screen.
If your adapter includes a graphics accelerator, the Performance page contains a Hardware Acceleration slider you can use to control the degree of graphic display assistance provided by your adapter hardware. In Windows XP, the Performance page is referred to as the Troubleshoot page.
Setting the Hardware Acceleration slider to the Full position activates all the adapter's hardware acceleration features. The necessary adjustments for various problems can be seen in Table 15.16 for Windows XP and in Table 15.17 for other versions of Windows.
Table 15.16 Using Graphics Acceleration Settings to Troubleshoot Windows XP Acceleration Setting | When to Use | Effect of Setting | Long-Term Solution |
Left* | The display works in Safe or VGA mode but is corrupted in other modes. | There's no acceleration. | Update display, DirectX, and mouse drivers. |
One click from left* | 2D and 3D graphics driver problems; mouse driver problems. | It disables all but basic acceleration. | Update display, DirectX, and mouse drivers. |
Two clicks from left* | 3D acceleration problems. | It disables DirectX, DirectDraw, and Direct 3D acceleration (mainly used by 3D games). | Update DirectX drivers. |
Two clicks from right* | Display driver problems. | It disables cursor and drawing accelerations. | Update display drivers. |
One click from right* | Mouse pointer corruption. | It disables mouse and pointer acceleration. | Update mouse drivers. |
Right | Normal operation. | It enables full acceleration. | N/A |
*Disable write combining, which is a method for speeding up screen display, whenever you select any setting other than full acceleration to improve stability. Reenable write combining after you install updated drivers and retry.
Table 15.17 Using Graphics Acceleration Settings to Troubleshoot Other Windows Versions Mouse Pointer Location | When to Use | Effects of Setting | Long-Term Solution |
Left | Display works in Safe or VGA mode, but it is corrupted in other modes. | It disables all acceleration. | Update display and mouse drivers. |
One click from left | 2D and 3D graphics driver problems, mouse driver problems. | Basic acceleration only. | Update display and mouse drivers. |
One click from right | Mouse pointer corruption. | It disables mouse pointer acceleration. | Update mouse drivers. |
Right | Normal operation. | Full acceleration. | N/A |
If you're not certain of which setting is the best for your situation, use this procedure: Move the slider one notch to the left to address mouse display problems by disabling the hardware's cursor support in the display driver. This is the equivalent of adding the SWCursor=1 directive to the [Display] section of the System.ini file in Windows 9x/Me.
If you are having problems with 2D graphics in Windows XP only, but 3D applications work correctly, move the slider to the second notch from the right to disable cursor drawing and acceleration.
Moving the slider another notch (to the third notch from the right in Windows XP or the second notch from the right in earlier versions) prevents the adapter from performing certain bit-block transfers; it disables 3D functions of DirectX in Windows XP. With some drivers, this setting also disables memory-mapped I/O. This is the equivalent of adding the Mmio=0 directive to the [Display] section of System.ini and the SafeMode=1 directive to the [Windows] section of Win.ini (and the SWCursor directive mentioned previously) in Windows 9x/Me.
Moving the slider to the None setting (the far left) adds the SafeMode=2 directive to the [Windows] section of the Win.ini file in Windows 9x/Me. This disables all hardware acceleration support on all versions of Windows and forces the operating system to use only the device-independent bitmap (DIB) engine to display images, rather than bit-block transfers. Use this setting when you experience frequent screen lockups or receive invalid page fault error messages.
Note -If you need to disable any of the video hardware features listed earlier, this often indicates a buggy video or mouse driver. If you download and install updated video and mouse drivers, you should be able to revert to full acceleration. You should also download an updated version of DirectX for your version of Windows.
In most cases, another tab called Color Management is also available. You can select a color profile for your monitor to enable more accurate color matching for use with graphics programs and printers.
Video cards with advanced 3D acceleration features often have additional properties; these are discussed later in this chapter.
Next: Multiple Monitors >>
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 This chapter is from Upgrading and Repairing PCs, 16th edition,by Scott Mueller. (Que Books, 2004, ISBN: 0789731738). Check it out at your favorite bookstore today. Buy this book now.
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