Tips & tricks for Ubuntu

Rotating PDFs

If you use Evince as your PDF viewer, you can easily rotate PDF documents if they arrive askew. Press Ctrl+Right arrow to rotate the document to the right by 90-degree increments or press Ctrl+Left arrow to rotate them in the opposite direction.

ATI Graphics: Turning Off Fan Noise

A rather irritating bug in Ubuntu 12.04 happens for some users with the newer ATI graphics cards. This bug may extend to Ubuntu 12.10 as well; at press time, no solution was found, but a bug report exists [2]. If you're using the fglrx proprietary ATI graphics driver, then, along with great graphics performance, you also get an annoying bug: When you aren't using the desktop for a while, the screen goes dark with an accompanying screen lock. That's OK, except that the fan starts whirring at full speed even if you're not doing anything. When you return to the desktop to check the problem, it stops. So, what's happening? An SSH connection shows where the problem lies: Compiz uses all the CPU, which sets off the fan.

The problem can be resolved, but the bug report suggests two competing workarounds. For the first, go to Dash and enter AMD to start the AMD Catalyst Control Center. Click 3D | More Settings and move the Wait for vertical refresh slider until the text On, unless application specifies appears under it (Figure 3). Then click Apply and OK to change the setting. Give the computer a bit of rest and wait for the back screensaver to appear. If the fan noise doesn't return after a few minutes, you're good to go.

Figure 3: According to a workaround, using the Catalyst Control Center can turn off the annoying fan noise. During testing, however, the second approach worked better.

If the problem persists, you can try the second workaround: Install the compizconfig-settings-manager package and invoke the Compiz Configuration Settings Manager by entering CC in Dash. Navigate to the OpenGL entry and remove the checkmark from the Sync to VBlank option. Close the Settings Manager and, in a few minutes, see whether the problem has been fixed. During testing, this second workaround let us rest easy.