Asus M5A-78L-MLX Build

I just finished with building a new system using the Asus M5A-78L-MLX mother board. This model has a parallel port and can run a single core AMD processor so I suspected that the performance would be good and it is. I put the entire system together for under $275 which is more than I wanted to spend but the results were worth it. Without any tweaking yet the Maximum Jitter numbers are very low depending upon the amount of stress on the system. With no load the base thread is 4319ns and the servo thread 3985ns. With a heavy load consisting of web browsing, Glxgears, file I/o's, and running paint programs the numbers climb to 9510 for base and 7510 for servo. When I add in running videos the maximum base climbs to 13504ns and the servo thread reaches 8266ns. I've tried adding more load but can't get the base number up any higher.
I'll report back after I've had a chance to tweak the system but for $54 this is a pretty nice mobo for Linuxcnc.

Hi

Thanks for the report, we need a stock of modern boards that work well, the manufacturers never seem to keep one in production for very long.

It is good to know that an AMD based board works well, they went through a phase of using awful graphics chips which gave poor results.
ASUS also kept using Realtek LAN and Audio chipsets that were not supported by Linux kernel drivers before 3.x.x
But at least now you can easily use Ubuntu 12.04 and sebs 3.4.55 kernel, so everything should work with that.

When you have the full figures, put them on the wiki with a short write up,
wiki.linuxcnc.org/cgi-bin/wiki.pl?Latency-Test
or post them here and I will do it

regards

I've fought the Realtek battle for years and it isn't just with Linux systems. Some windows lashups don't like it either. I've always had very good results with AMD Sempron chips in every system I've built but this new setup is not as good as some of my very old ones. I haven't had time to do much work with the new board yet but will post updates as I get back to it. I built this largely as an experiment and as a potential controller for an upcoming mill conversion project.

The new Celeron J1800 (possibly J1900,J2900 as well)
MBs look very promising.

A quick check with a Gigabyte J1800N-DH2 shows about
8 usec latency with Firefox running flash videos and multiple GLXgears running
The Gigabyte has a parallel port (on a header) that works in EPP mode
It also supports with a 4 KHz servo thread (which the previous Atom MBs will not do)

The J1800 is a dual core 2.4 GHz CPU thats roughly 2 to 3 times as fast as the previous Atoms (D525 D2800)
had has built in Intel video. These are low power (10W TDP max) chips that use passive
cooling. There are at least 8 MB companies making these including Gigabyte, Asus, ASRock, ECS, MSI, and Biostar

I wish I knew that a few days ago. I'll try to get my hands on one.
In the mean time I did a small page that describes my thought process about this particular project and the components I used. The url is:
chopperhandbook.com/cnc/cnc-comp2.htm

I should note that I am not suggesting that anyone rush out and buy one of these new
MBs I suspect there will be at least a few months of time getting everything working smoothly

Problems I have had so far:

RTAI 2.6.122 kernel from 10.04 works fine, 3.4.55 has problems with Intel video

BIOS needed to be updated to even boot Linux

So any updates to your Gigabyte J1800N-DH2? Curious if you have tried running linux 3.5.7 kernel with xenomai? this looks like a real promising platform.

I am currently using preemt-rt kernel 3.14
I would expect some wait to get xenomai and RTAI running well
on the J1800/J1900 motherboards since it requires a 3.11 or > kernel
for full video support. Other than slow video, the 2.6 RTAI kernel works well