Sun VirtualBox problem

I just upgraded to VirtualBox-2.0.2_36488_fedora9-1.i386 [not the OSE] and it wouldn't start.
The error message was

Failed to create the VirtualBox COM object.
The application will now terminate.
Callee RC: NS_ERROR_FACTORY_NOT_REGISTERED (0x80040154)


I don't know what it means, but probably looks like some interprocess communication issue.

Ahh ! I removed the [root owned, something I find very weird] directory /tmp/.vbox-prashant-ipc and vbox started very well; but now somehow it can not connect to the host sound.

CPU about to vaporize !!

One fine day, I suddenly felt the urge to OC my CPU for no apparent reason. I had not looked at the temps since a long time, so I just checked the temps before OC'ing, just to get the feel how worse it could get when I actually OC.

I happen to own a powerhouse CPU (~100W), the infamous Pentium D 820. On top of that, I still use the stock cooling, and the room temperature is around ~30 degree Celsius, making board ambient temp~50. I have not even OC'd the chip.
When I run my experimental DES cracker on this dual core boiler-plate, this is what happens - CPU temperature is 84 degrees. The fun part is that this is not the accurate temperature as Intel did some cheap cost-cutting. Some say that the actual could be higher by 10 degrees than what's reported.



Then I realized that I had not cleaned the box for quite some time. I took it apart and get the reason -- ~2mm thick dust layer on the heat sink baffles.


The sad part is that the thermal paste has disappeared and I can no longer get it for free. So the worst case temps are still around 75-80. Hope things will improve when I apply it.

The spurious OC (s)urge went down as fast as it rose.

NVidia PhysX - Driver update

With the updated NVidia forceware driver version 178.13, my cheap little GeForce 8800GS (OC'd) started supporting NVidia PhysX. Tech demos from NVidia, like 'The Great Kulu' and the demo game 'Warmonger' work just awesome. Physics unlike any I had ever seen on my machine! It is a big big plus over CPU physics.

Can't wait to play some interesting game which uses Nvidia PhysX for a better gameplay and effects!

The driver update also claims ~10% boost in performance - which is evident when playing "Assisin's Creed (DX10)" :)

Even the Linux driver version 177.80 has numerous improvements wrt. kde4 rendering. Makes me even more happier :D

--update Crazy machines 2 by FAKT uses PhysX. Can't wait to play it !

networked sound using pulseaudio/phonon

It just happened so that my machine did not have any speakers attached, my room mate had them; and we wanted to watch a movie on my 19". We tried with lamer options like ssh with X forwarding; but the bandwidth of 100mbps lan was quite not enough (the mvk video was close to HD btw). The jitter was high.

Then we realized that ssh was not made for audio/video streaming; and we started looking for audio streaming solutions.

Turns out that the new pulseauadio that ships with fedora9 can deliver networked sound, wow ! we tried the $PULSE_SERVER approach, but could not get it to work.

The config that finally worked was this one.

this is what it says -
++cut++

On the sender side simply load the RTP sender module:

pactl load-module module-rtp-send

On the reciever sides, create an RTP source:

pactl load-module module-null-sink sink_name=rtp
pactl load-module module-rtp-recv sink=rtp
pactl set-default-source rtp_monitor

Now the audio data will be available from the default source rtp_monitor.

--cut--

UPDATE : does not seem to work any more with pulseaudio 0.9.21 :(

--
prashant

lean X

I use Eclipse JDT with a huge project code, and naturally it hogs memory and does annoying swapping. Among others are Thunderbird, amarok, firefox(with ~50 tabs open on an average) and pidin. I happen to use mere 1G RAM. With no alternative to eclipse (mainly because of productivity boost), I started looking at other processes that consumed quite some memory. After some review, I found that GNOME was an important candidate.

So, instead of running a full fledged GNOME session, I just ran the parts of it that are absolutely necessary to me (after all, that's the beauty of xNIX systems).

This is what I did -

• modify /etc/inittab to start in runlevel 3 by default

and wrote a script

leanX.sh

export DISPLAY=:0 Xorg& xterm&

That's pretty much it. Within xterm, I can run almost anything :). Although the xterm is not necessary, it saves me from the pain of going to console mode and launching something.

This has saved me a few bucks for RAM upgrade !

The story doesn't end here. If you want almost all GNOME functionality like panel and menus, task list panel and stuff; without crap like wallpaper, session and other accesibility related features - you could well do this :

leanGNOME.sh

export DISPLAY=:0
Xorg&
metacity& (or fusion-icon&)
gnome-panel&
pulseaudio& (if you are interested in having sound support)
gnome-session&(if you want the pre-saved session to be restored. I wouldn't use this though)


There are other desktops too - like xfce and cde, but I really like the feeling of closeness to GNOME - can't explain why :)
--
prashant

n Sync

a nice linux util a colleague had introduced me to - sync!

At times, my system just refuses to work for many reasons and the only option left is a hard reboot. Before touching that tiny button, just run `sync` as root and at least my filesystem remains clean - it flushes all in core buffers to disk and also updates the superblock.

Not sure if it also works with fuse ie. things like ntfs-3g; but I suppose it does, because I never had a unclean ntfs partition after I started doing sync.

Overclocking nVidia cards in Linux

You don't need CoolBits or nvclock any more !

I assume you have the latest drivers installed. If not, get them for your distro. For Fedora 9, I use 'yum install xorg-x11-drv-nvidia' from livna. I am using 173.14.09 at the time of writing.

add Option "Coolbits" "1" in devices section of /etx/X11/xorg.conf or XF86config

it should look like

Section "Device"
Identifier  "Videocard0"
Driver      "nvidia"
VendorName  "NVIDIA Corporation"
BoardName   "NVidia GeForce 8800 GS"
Option     "Coolbits" "1"
EndSection

and restart the X server [logout, init 3, init 5], fire up nvidia-settings
and you will get the familiar controls :D




enjoy!

Remember that you can potentially render the beast useless by not respecting the real world freq limitations. You are warned.

Thanks to The_Jester @ http://www.overclock.net/faqs/115417-how-overclock-your-nvidia-card-under.html