The DPI problem was fixed very easily by following the instructions on the link I provided in my previous post, I calculated that my Sony Bravia KDL 32S3000 had dimensions of 700mm x 390mm and a native resolution of 1366x768.

$ xdpyinfo | grep dimensions
$ xdpyinfo | grep "dots per inch"

Converting the millimetres to inches and dividing the resolution by the inches dimensions gave me DPI of 50x50, surprisingly low. I believe this is because the KDL 32S3000 is not a full HD TV but only 1080i. Setting this in /etc/X11/xorg.conf cured the problem with the KDM login manager.

Section "Monitor"
    Identifier "Monitor0"
    Option   "DPI" "50 x 50"
EndSection

Installed the Nvidia binary driver, which worked fine, except that, as I’ve found on a few installs recently the KDE screen DPI defaults to something absurd, resulting in unreadably small fonts. Easily fixed in KDE, via System Settings (as long as you know your way around!), but haven’t yet found out how to do it in KDM (the login manager). This is not a huge problem, as it is easy enough to type in your password, and anyway on a home theatre PC you probably want it automatically logging in. That said, I am determined to fix this problem when I have some time. Interestingly this was also the case on our existing mythbox, which has completely different hardware, the common thread being the nvidia driver. I suspect the issue may be related to the KDE virtual desktop, and the nvidia driver calculating this back to a reasonable DPI. This link may help, I will give this a go when I have some time.

Anyway, the good news is that, with the binary driver installed, the standard KDE compositing is working beautifully.

As to sound, this is still not working via HDMI, but is working fine through the sound outputs. This seems to be a widespread issue, which I think has been resolved, so it’s just a matter of waiting for the fix to filter downstream. In the meantime, I will continue to work as we do on our existing mythbox, with a 2.1 speaker system plugged into the HTPC.

It switched on okay, but the front LEDs were not working, neither the power nor the disk LED; so it seems that they are not wired up correctly, although I really can’t see how I could have got it wrong.

It booted into a Kubuntu 10.04 USB stick without any problems. The network card was detected correctly and I was able to browse the Internet without any configuration. The Nvidia card was detected correctly, using the open source driver, obviously I will install the Nvidia binary driver. The only strangeness was the lack of sound via the HDMI cable, but looking in the BIOS afterward I noticed an option “Audio via HDMI” which I have enabled, it was set to auto, but maybe that’ll make a difference.

It is difficult to say how quiet it is at present, as any sound it was making was being drowned out by our noisy old mythbox.

I can’t wait to have a decent chunk of time to start the installation.