Re: [Discuss-gnuradio] Performance Issues

[CEL]

Hello Tellrell,

first observation: Step away from Ubuntu 14.04, if possible. Its
compilers aren't really as cool as they could be (there's been a lot of
performance improvement in both GCC and Clang in the last four years),
and you do care about performance.
Also, Ubuntu 14.04 won't be around for much longer, so if this is a new
application, switching to the next LTS is probably a good idea (by the
way, I've not been able to find significant performance regressions in
simulation-only GNU Radio flow graphs due to KPTI fixes, i.e. meltdown
fixes).

Then: Virtualizers are getting better every day; whether that makes
them the best choice for SDR is something that I can't generally
answer. Fact is that USB3 handthrough to VMs is known to be rather
flaky, so if you're using a USRP B2xx, then native is most likely the
way to go. 
If you're using a high-end network card, and a good hypervisor, chances
are you can actually have a virtualized dedicated network card in the
VM (if that is the case, you probably know yourself, because you'd have
configured your VM to be "owner" of part of your network card).

What you should most definitely not do is have a "NAT" networking
solution between your VM and your Host – that way, every UDP packet for
a network-attached USRP would have to go through a packet
analyzer/rewriter, and that's going to eat CPU.

I don't know what your CustomBlock does, but if it not a hier_blopck,
Python is really not the thing you want for highest performance. Also,
to avoid the vec2stream, make your block consume vectors instead of
single samples; the complex_to_magnitude_squared block can be
configured to directly work on vectors, too!

Generally, you'll find that most guys on here are happy running a
modern Linux on their machines. Setting up a Fedora 27 that boots
alternatively to the pre-installed windows took about 15 minutes on my
new laptop, but it's definitely not the first installation of that I
did, so calculate let's say 30 minutes. That's actually something that
you might just want to try out. After that, it was really just a matter
of "sudo dnf update -y; dnf install -y gnuradio" to be up and running a
halfway recent GNU Radio. On debian unstable or testing, you'd get
something even more recent.

Best regards,
Marcus

On Tue, 2018-02-20 at 08:48 -0500, Tellrell White wrote:
> Hello Guys
> Currently I'm running a flow graph that looks like the following:
> 
> UHD Source -> Stream2Vec -> FFT -> Vec2Stream -> Com2Mag^2 -> 
> CustomBlock(Python)
> 
> I'm running this block inside of a virtual machine running ubuntu 14.04 LTS. 
> The host machine runs Windows with an Intel Core i7-4700 MQ processor running 
> at 2.4GHZ with 8GB of RAM. 
> 
> Running the flow graph shown above in the VM is a struggle resulting in 
> freezing after a few seconds so my question is would it better to go another 
> route for performance, either, by installing UHD and Gnu Radio on the host 
> machine running windows or using another machine and dual booting and 
> installing linux, GNU Radio, and UHD for this application? 
> 
> Regards
> Tellrell White 
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

smime.p7s
Description: S/MIME cryptographic signature