Good Base PC for low latency

[andrew bishop]

Good day everyone. I'm looking for some advice on a new pc for a second CNC i'm preparing to build. i already have one running but i'm looking for a good base PC to start with so that i dont run into issues fumbling around buying parts and so forth. I dont mind building the PC just trying to figure out what components will work the very best. I had alot of issues with my first machine which took along time to get sorted out so i'm trying to reach out NOW before i start ordering parts for the build. 

[hosanee...@gmail.com]

Hi Andrew, 

I would say the best thing you could buy is a core i-7. These are known for better multitasking purposes since they handle threads a lot better as opposed to the i5 or i3. If you can get something with a big cache on the chip (8MB cache > 6MB cache), will help you a lot since the computer architecture will be able to keep more program and data memory within the processor making it faster and more efficient. Of course as always get ram (8gb will work fine, 16gb will work better.

However when it comes down to it, the operating system is perhaps the most important part. Since you need to adhere to these real time constraints, stripped down versions of OS's tend to work better since there's less overhead in the background processes running. I am assuming you are using linux? One of the minimal distro's should work plenty fine. 

Just know that people have successfully run fully functioning CNC machines on Single board computers with linux CNC on there just fine. Machinekit is a group of people that helps build the linux kernel for real time constraints. 

I am fairly new to CNC also and have been a lot of research for it (electrical engineering student) so i would probably get someone well versed to confirm what I just said, or suggest something else if I am not in the ballpark of what should work. 

Good luck with your machine!

[hosanee...@gmail.com]

I re-elaborated I guess about the machine kit... forgot i was responding to one of their posts and not someone else's :P 

On Monday, January 23, 2017 at 10:55:09 AM UTC-7, andrew bishop wrote:

[Bas de Bruijn]

> On 23 Jan 2017, at 21:03, hosanee...@gmail.com wrote:
>
> Machinekit is a group of people that helps build the linux kernel for real time constraints.

Machinekit is a fork of Linuxcnc. Among the goals were multiple kernels (at the time rtai, xenomai and rt-preempt), multiple platforms (arm next to the i386 and x64) and applications for more uses than milling/turning.

Have a look at for example the work on the de0-nano-soc (where the hostmot firmware runs in the de0-nano fpga), and the recent multicore changes being tested.

[Bas de Bruijn]

Oops, and i forgot to mention haltalk and the remote GUI capabilities.

[andrew bishop]

the machine i'm running now is an old i7 with linux cnc on it for my primary mill. i had heard good things about older hardware but i'll start my search with some nice vintage i7's and see what i can come up with. i just want to make sure this build goes off with out a hitch. 

[andrew bishop]

http://www.ebay.com/itm/Dell-Optiplex-SFF-980-i7-860-Quad-2-8GHz-8GB-1TB-DVD-RW-Win-7-Pro-64Bit-/252730566706?hash=item3ad7ea6832:g:BlUAAOSw44BYf-8T something like this looks to be a good start. 

[hosanee...@gmail.com]

That's great for the price. Just did some benchmark testing on a OptiPlex 980 today for some code. I would recommend upgrading memory to SSD though. Just better and more reliable in vibrational environments

On Monday, January 23, 2017 at 5:57:55 PM UTC-7, andrew bishop wrote: