Re: [Discuss-gnuradio] Performance Issues

[Ralph A. Schmid, dk5ras]

About the discussion pro and con VM, my experiences with VMware are quite good. 
I am using gnuradio on a Micosoft Surface pro 3, Win 10, i7-CPU, 8GB RAM, using 
Kubuntu 16.04 in the VM. Gnuradio and uhd are always built from sources, from 
master branches. When Windows has no other open application running and the 
focus stays on the VM, it runs quite smooth, and openLTE with 5 MHz bandwidth 
works so far good, also transmitting DVB-T with gnuradio is possible. The used 
radio is an Ettus B210, connected with USB3.

The main reason for my choice is mobility, need this stuff being available when 
traveling :) Dual boot on the surface was at least a few years ago a PITA, and 
MS tended to kill the bootloader with updates. Don't know it this is better 
nowadays.

Ralph, dk5ras. 

> -----Original Message-----
> From: Discuss-gnuradio [mailto:discuss-gnuradio-
> address@hidden On Behalf Of Müller, Marcus (CEL)
> Sent: Tuesday, February 20, 2018 3:36 PM
> To: address@hidden; address@hidden
> Subject: Re: [Discuss-gnuradio] Performance Issues
> 
> 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
> > _______________________________________________
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