# USRP N210 overflows in virtual machine using GnuRadio

**URL:** <https://www.ruby-forum.com/t/usrp-n210-overflows-in-virtual-machine-using-gnuradio/253638>\
**Category:** GNU Radio\
**Created:** [January 24, 2020, 12:25pm UTC](https://www.ruby-forum.com/t/usrp-n210-overflows-in-virtual-machine-using-gnuradio/253638 "2020-01-24T12:25:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ben\_F](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/ad7895/32.png) [@ben\_F](https://www.ruby-forum.com/u/ben_F)\
**Post date:** [January 24, 2020, 12:25pm UTC](https://www.ruby-forum.com/t/usrp-n210-overflows-in-virtual-machine-using-gnuradio/253638/1 "2020-01-24T12:25:56Z")

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I am using the USRP N210 through a Debian (4.19.0-6-amd64 #1 SMP Debian 4.19.67-2+deb10u1) VM and run very quickly into processing overflow. GnuRadio-Companion is printing the letter “D” the moment one of the CPUs load is reaching 100 %. This was tested by increasing the number of taps for a low-pass filter, as shown in the picture with a sampling rate of 6.25 MHz.

I have done all instructions on [How to tune an USRP](https://kb.ettus.com/USRP_Host_Performance_Tuning_Tips_and_Tricks), except the CPU governor. This is because I am not able to do this due to a missing driver reported by cpufreq-info. The exact output is

> No or unknown cpufreq driver is active on this CPU.

The output of the lscpu command is also shown in a picture.

Has anyone an idea how I can resolve the problem? Or is GnuRadio just not fully supported for VMs?

 ![image](https://www.ruby-forum.com/uploads/default/original/2X/f/f5120bc358c2dbde81daa2395719e4fa19f34e48.png)

 ![image](https://www.ruby-forum.com/uploads/default/original/2X/f/fe686ad6e939bf7124074ee497c74944522602be.png)

 ![image](https://www.ruby-forum.com/uploads/default/original/2X/6/612eb07b24ac806edadca901ab923a65dfc5ee49.png)

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**Author:** ![ThunderGod](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/96bed5/32.png) [@ThunderGod](https://www.ruby-forum.com/u/ThunderGod)\
**Post date:** [February 3, 2020, 10:01am UTC](https://www.ruby-forum.com/t/usrp-n210-overflows-in-virtual-machine-using-gnuradio/253638/3 "2020-02-03T10:01:49Z")

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I’ve tried that years ago … even with XCP virtual host … same result  
I think the problem is the low performance of the visualized USB 3.0 port