[mythtv-users] Babelbox: A potentially useful new low-cost frontend?

[Robert Johnston]

On 8/21/06, Luke Rosenthal <mythtv at harderstuff.net> wrote:
> > Are you using the OpenGL painter or the QT painter? Is your MySQL box
> > heavily loaded? Do you have Query Tracing switched on? Have you enabled
> > DMA in your HDParm config?
>
> I'm using the QT painter.  Would this make a big difference to the way the
> menus run?  Would running OpenGL be possible with an old Geforce MX420?
> Am I asking too much of an old P4 2gHz (400mHz FSB) and this graphics
> adapter?

The QT painter mixes everything in software. Your GeForce would be
more than up to the task of running Myth with OpenGL at virtually any
resolution, but it would not be enough to decode HDTV (Even with
XvMC). This does, however, require that you're using the NVidia Binary
drivers ("nvidia" in your xorg config) rather than the NV Framebuffer
drivers ("nv" in xorg config). This would also help the speed of the
box in general, as the NVidia drivers offload a lot of blitting and
the like on the GPU.

> Mysql is not doing anything other than serve myth, and is local to the
> box, so no.  It never consumes more than about 10% CPU.
>
> Couldn't find anything regarding Query Tracing in the wiki - is this a
> myth feature or a mysql feature?  I've run optimize_mythdb.pl, but it made
> no noticeable difference.

This is a MySQL thing, and if you've not enabled it, it's not on.
(It's EXTREMELY HDD and CPU intensive, and is NEVER enabled out of the
box).

> HDparm stats:
>
> /dev/sda:
>  Timing buffered disk reads:  196 MB in  3.03 seconds =  64.72 MB/sec
>
> /dev/sda:
>  Timing cached reads:   1200 MB in  2.00 seconds = 599.42 MB/sec
>
> Issuing the command "hdparm -c1 -d1 -X66 /dev/sda" yields:
>
> /dev/sda:
>  setting 32-bit IO_support flag to 1
>  HDIO_SET_32BIT failed: Invalid argument
>  setting using_dma to 1 (on)
>  HDIO_SET_DMA failed: Inappropriate ioctl for device
>  setting xfermode to 66 (UltraDMA mode2)
>  HDIO_DRIVE_CMD(setxfermode) failed: Input/output error
>  IO_support   =  0 (default 16-bit)
>
> Is it even possible to do this on SATA disks?

According to the Gentoo Wiki:
(http://gentoo-wiki.com/HOWTO_Use_hdparm_to_improve_IDE_device_performance)

I get "Operation not supported" errors on even basic commands such as
'hdparm -i'

You are probaly attempting to use hdparm on a SATA or some other
bizarre drive. hdparm currently has very limited support for SATA
drives however these drives are generally setup automatically to use
most of the more decent settings. You should be able to get the basic
information (without the -i) and benchmarking to work. Try
benchmarking the drive to check if you are getting good speeds
(generally above 1000MB for cached reads and above 50MB for buffered
reads).

sdparm is virtually the same as hdparm. blktool is an alternatative to
hdparm with some support for SATA and SCSI drives.

So, try blktool to see if it can improve your numbers.

Oh, and as one last thing, make sure you've got your swap partition
turned on. I've recently shuffled partitions (Getting rid of the now
unneeded "Live TV" ringbuffer) and my box no longer mounts it's swap
automagically.
-- 
Robert "Anaerin" Johnston