[Discuss-gnuradio] USRP N200 Overflow (printing D) when using a new Intel NUC

Hi!

I have been using USRP N200 (with LFRX daughterboard) with an Intel NUC
(BOXNUC5I5RYH) for quite a long time, and everything has been working well.

Recently I purchased a new NUC of a recent version (BOXNUC7I5BNK), and
the overflow problem (printing D) occurred.

So I made a test. I installed Ubuntu 17.10 on both the old and the new
NUCs, and installed exactly the same software. Then I tested these two
NUCs with the same USRP and confirmed that the overflow problem only
occurs with the new NUC.

I made a simple script for the test as shown in the attached figure.
With the new NUC, the letter D is printed once in a while as shown below:

-----------------------------------Output--------------------------------------------
linux; GNU C++ version 6.2.0 20161027; Boost_106200;
UHD_003.009.005-0-unknown

-- Opening a USRP2/N-Series device...
-- Current recv frame size: 1472 bytes
-- Current send frame size: 1472 bytes
-- Detecting internal GPSDO.... Found an internal GPSDO: Jackson-Labs,
FireFly , Firmware Rev 0.929
-- Setting references to the internal GPSDO
1532658018 3595
1532658019 3362
1532658020 2861
D1532658021 666
1532658022 587
1532658023 722
1532658024 780
1532658025 477
1532658026 703
DD1532658027 759
1532658028 553
1532658029 618
1532658030 581
1532658031 474
-----------------------------------------------------------------------------------------------

With the old NUC, there is no overflow at all.

So it seems the overflow problem is associated with the hardware of the
new NUC (BOXNUC7I5BNK). My question is that is there any method to avoid
this overflow problem? If I have to drop this new NUC, what part of the
NUC is causing this problem and what types of PCs may have the same
problem and I should avoid in the future?

Thanks in advance!

Ting Wu