What to do with these PCs?

I have 2 mobos and a selection of components. After several days of interchanging components and testing with pre-built Live CDs, running 10x glxgears, moving windows around and launching firefox, I get the following:

1. MSI K8 mobo, BIOS fully optimized for minimum latency, 2 x 1GB Corsair ram, Radeon 128Mb PCI (NOT PCI-E) graphics, Ubuntu 10.04 LinuxCNC Live CD: 16K latency with 100k+ spike on first launch of firefox. Also tested against an installed version 10.04 and had some unresolved freeze issues which could only be recovered by a hard shutdown.

2. MSI K8 mobo, BIOS fully optimized for minimum latency, 2 x 1GB Corsair ram, Radeon 256Mb AGP graphics, Ubuntu 10.04 LinuxCNC Live CD: 19K latency. No obvious spikes, however this card did cause some boot issues on a previous test against an installed 10.04 (same HDD as above). The HDD has since been tested and appears to be good.

3. MSI K8 mobo, BIOS fully optimized for minimum latency, 2 x 1GB Corsair ram, Nvidia 256Mb AGP graphics, Ubuntu 10.04 LinuxCNC Live CD: 14K latency with occasional 100K+ spikes (unresolved).

4. HP GL8E (a.k.a Asus PTGD1-LA) mobo, dumbed-down BIOS as default due to HP restrictions. No BIOS upgrade available. 2 x 1GB Corsair ram, HP PCI-E graphics (Radeon X600??), Ubuntu 10.04 LinuxCNC Live CD : latency 20K with 44K spike when Firefox launched.

5. Hardware as above, using LinuxCNC Ubuntu 8.04: latency max 12.6K. No spikes, despite heavy loading. Graphics flickery, max resolution 1024 x 768. Driver unknown (lspci-vv and lsmod didn't clarify). Doesn't shutdown properly - have to press power button.

6. HP GL8E (a.k.a Asus PTGD1-LA) mobo, dumbed-down BIOS as default due to HP restrictions. No BIOS upgrade available. 2 x 1GB Corsair ram, Radeon 5450 PCI-E graphics, Ubuntu 10.04 LinuxCNC Live CD : latency 14K with 38K spikes when maximizing windows and/or launching firefox for first time.

7. Hardware as above, using LinuxCNC Ubuntu 8.04: latency 7.2K. No spikes, despite heavy loading. Graphics flickery, max resolution 800 x 600. Driver unknown (lspci-vv and lsmod didn't clarify). Doesn't shutdown properly - have to press power button.

Soooo....the HP mobo appears to be more stable and gives the lowest latency under Ubuntu 8.04 (but is crap using 10.04), however the 8.04 O.S. has some issues - namely the poor graphics resolution and shutdown problem.

I'm no Linux newbie (been using it on all my computers since 2008) and do a fair bit of programming in Python, so am a bit geeky but not hardcore. I generally prefer Debian based distros and often default to LMDE with XFCE or MATE desktop.

The question is; which hardware and OS should I use? I'm not very impressed with Ubuntu 8.04 due to the poor GUI and 10.04 seems a bit troublesome. I' m also not sure how this OS will work with LinuxCNC 2.5 and installing my ndiswrapper dependent wifi card without an internet connection appears to be a mammoth task. I'm leaning towards the HP hardware because it is more stable, however I haven't (yet) tested the MSI hardware with 8.04.

Both CPUS are single core and manufactured around 2004/2005, so the older Kernel will most likely be the way forward, but what other options do I have? Are there any none-Ubuntu versions of LinuxCNC available? Can I use the old kernel with a newer OS?

Please help - I don't have many more strands of hair left to pull out!

1. MSI K8 mobo, BIOS fully optimized for minimum latency, 2 x 1GB Corsair ram, Radeon 128Mb PCI (NOT PCI-E) graphics, Ubuntu 10.04 LinuxCNC Live CD: 16K latency with 100k+ spike on first launch of firefox. Also tested against an installed version 10.04 and had some unresolved freeze issues which could only be recovered by a hard shutdown.

2. MSI K8 mobo, BIOS fully optimized for minimum latency, 2 x 1GB Corsair ram, Radeon 256Mb AGP graphics, Ubuntu 10.04 LinuxCNC Live CD: 19K latency. No obvious spikes, however this card did cause some boot issues on a previous test against an installed 10.04 (same HDD as above). The HDD has since been tested and appears to be good.

3. MSI K8 mobo, BIOS fully optimized for minimum latency, 2 x 1GB Corsair ram, Nvidia 256Mb AGP graphics, Ubuntu 10.04 LinuxCNC Live CD: 14K latency with occasional 100K+ spikes (unresolved).

4. HP GL8E (a.k.a Asus PTGD1-LA) mobo, dumbed-down BIOS as default due to HP restrictions. No BIOS upgrade available. 2 x 1GB Corsair ram, HP PCI-E graphics (Radeon X600??), Ubuntu 10.04 LinuxCNC Live CD : latency 20K with 44K spike when Firefox launched.

As I would expect, 10.04 will not run well on this board

5. Hardware as above, using LinuxCNC Ubuntu 8.04: latency max 12.6K. No spikes, despite heavy loading. Graphics flickery, max resolution 1024 x 768. Driver unknown (lspci-vv and lsmod didn't clarify). Doesn't shutdown properly - have to press power button.

Much better because it is a UniProcessor built kernel

The switching off manually is normal - the ACPI and other power functions are disabled in the kernel to minimise latency, which means the system stops but does not switch the computer off itself.
You will find that all the Num/Caps/Scroll lights flash when the system halts, you can then swittch off

Alternately remove the splash screen command from the kernel boot line and you will get a message that the system has halted

You can find the driver by lshw -C Display (if not installed apt-get install lshw)
lspci does not show it in that version, as I discovered myself when trying to diagnose problems

I would use the raedon AGP card with the raedon drivers
I have a 32MB Raedon AGP card installed on my P4s, with the xserver-xorg-video-raedon-whateverversion.deb installed.

Max jitter is 6K running Debian 7.1 and a home brew 3.5.7-rtai kernel, compiled for single processor.

If you want to try that it is at www.mgware.co.uk/debian/3.5.7-rtai-UP-1.deb
Go to the main site address and click on the left hand menu for New RTAI Kernels and you will find the actual pages and instructions.

You will have to compile your own linuxcnc, there are some instructions, but does assume some familiarity with compiling packages

I'm not very impressed with Ubuntu 8.04 due to the poor GUI and 10.04 seems a bit troublesome. I' m also not sure how this OS will work with LinuxCNC 2.5 and installing my ndiswrapper dependent wifi card

The gnome interface, gdm etc is crap, you can just get rid of it and use another window manager and display manager.
I use lxdm and icewm

Linuxcnc is independent of the Ubuntu version, but if you insist on using wifi with a windoze driver through a ndiswrapper, then you are probably going to have problems
Just use powerline adaptors and a wired connection, much simpler.

My advice, try to get it right with 8.04, get the right video drivers installed, should give beter resolutions, change the window manager to a much lighter one for a snappier interface and see how you get on

If you want to try my kernel on a modern Debian distro (Debian 7.1 Wheezy), then go ahead.
I have been using it for 6 months on all my workshop computers without any issues.

regards

Thanks for the help. The HP mobo seems to be the way forward. I'm going to try 8.04 installed and see if I can make it more usable with either an XFCE or LXDE desktops. I'd also like to try your kernel as I'm a big fan of Debian. Would you advise using straight Debian or perhaps one of these distros based on Stable? distrowatch.com/search.php?ostype=All&ca...re=All&status=Active

I just used a straight Debian install from the NetInstall iso (minimal iso and downloads everything else as it installs, saves getting an out of date distro package and then upgrading it later)

It was Wheezy 7.1, which I think is stable.

I initially set the kernel as 3.0.0-4-686-pae for my house computer which is a quad core newish machine.

For a P4 or earlier you may need to choose a 486 non pae built kernel to avoid the cmov errors etc that come with the change in the instruction set 486 > 686

good luck

Currently downloading cdimage.debian.org/debian-cd/7.2.0/i386/...fce-CD-1.iso.torrent

Hopefully 7.2 will work OK with your kernel...I'll let you know tomorrow!

Arceye: I've installed Wheezy and your kernel (and it boots OK and shows under 'uname -r) but can't do the 'Packages Second Stage' because I need an internet connection. I've got rid of the PCI wifi card because of its dependence on ndiswrapper and Windows drivers, but have a ralink based usb wifi stick which loads ok on the pae kernel but I can't get it working on your rtai one.

The pae kernel auto-loads the rt2800usb driver but I have to modprobe it under the rtai. Dmesg shows the usb dongle is loading when I unplug and re-plug BUT it says 'new high-speed USB device number 2 using ehci_hcd'

Any suggestions? Or is the wifi stuff disabled in your kernel?

EDIT: OK now. Found (weird) solution here: askubuntu.com/questions/134170/how-do-i-...orking/134176#134176

I've also noticed the rtai kernel halts but doesn't power off. Is that to be expected? Not major issue though...

Damn, it was all going so well....

In hindsight, should I have installed linux-headers-3.8.0-rtai-i386-IntelAtom.deb at that stage? Instinct says 'no' but I was in copy/paste heaven at the time...

EDIT: actually, instinct says I don't need either of these (as they were included with the 3.5.7-rtai kernel?) and I should now install linuxcnc? If so, should I remove the 3.8 headers? dpkg -r and dpkg -p don't seem to be working...

oh dear...

time for sleep!

birchy wrote:

I've also noticed the rtai kernel halts but doesn't power off. Is that to be expected? Not major issue though...

Yes, because all power management is disabled