Dotan Cohen wrote:
On 30/01/07, Philip Walden pwaldenlinux@pacbell.net wrote:
Philip Walden wrote:
Dotan Cohen wrote:
On a recent Dell laptop, what would cause DVD playback to be very choppy?
Besides the ATA DMA stuff, you may also want to check whether your MTRR is being set properly by the xorg X server.
Mine looks like this:
cat /proc/mtrr reg00: base=0x00100000 ( 1MB), size= 256MB: write-back, count=1 reg01: base=0xfc000000 (4032MB), size= 32MB: write-combining, count=1
You should have at least one "write-combining" entry which means the graphics card is set properly. Otherwise, performance can drop dramatically.
Here is a howto:
Thanks. I've nothing in /proc/mtrr:
[root@localhost ~]# ls /proc/mtrr /proc/mtrr
Try: cat /proc/mtrr reg00: base=0x00100000 ( 1MB), size= 256MB: write-back, count=1 reg01: base=0xfc000000 (4032MB), size= 32MB: write-combining, count=1
However, I'm having a hard time starting X, as it's already running! I've combed the logs in /var/logs but I don't have those lines. When I kill X with CTRL-ALT-ESC it starts right back up automatically, not letting me redirect it's output to a file.
I found mine using lspci
# /sbin/lspci -v : 01:05.0 VGA compatible controller: nVidia Corporation NV5 [RIVA TNT2/TNT2 Pro] (rev 15) (prog-if 00 [VGA]) Subsystem: ASUSTeK Computer Inc. AGP-V3800 SDRAM Flags: bus master, 66MHz, medium devsel, latency 40, IRQ 11 Memory at f5000000 (32-bit, non-prefetchable) [size=16M] Memory at fc000000 (32-bit, prefetchable) [size=32M] <========== use the prefetchable Capabilities: [60] Power Management version 1 Capabilities: [44] AGP version 2.0
I then added this to /etc/rc.local:
# set mtrr at least until Xorg 7.1 is added to the distribution echo "base=0xfc000000 size=0x2000000 type=write-combining" >| /proc/mtrr
Just for kicks, here's the output of "lspci -v" as suggested by the same page:
:
01:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility X1400 (prog-if 00 [VGA]) Subsystem: Dell Unknown device 2003 Flags: bus master, fast devsel, latency 0, IRQ 4 Memory at d0000000 (32-bit, prefetchable) [size=256M]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I/O ports at ee00 [size=256] Memory at efdf0000 (32-bit, non-prefetchable) [size=64K] [virtual] Expansion ROM at efd00000 [disabled] [size=128K] Capabilities: [50] Power Management version 2 Capabilities: [58] Express Legacy Endpoint IRQ 0 Capabilities: [80] Message Signalled Interrupts: 64bit+Queue=0/0 Enable-
I would guess your's would look like:
echo "base=0xd0000000 size=0x10000000 type=write-combining" >| /proc/mtrr