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Discussion and technical support related to USRP, UHD, RFNoC
View all threadsExtending duration of high-rate captures with the X410
I think I am mistaken. If you are only streaming a single channel, the
--multi_streamer option will likely not change a thing. I was assuming you
had multiple channels.
Rob
On Tue, Mar 12, 2024 at 5:40 PM Rob Kossler rkossler@nd.edu wrote:
Your mount command with tmpfs looks correct. Here is what mine is in my
/etc/fstab file (with 264GB avail RAM)
tmpfs /media/ramfolder/ tmpfs rw,nosuid,nodev,size=200G 0 0
You might want to try rx_samples_to_file with the --multi_streamer option.
I expect you will get better performance. Also, you can take your RAM FS
size higher from 8G to probably 60G if you want to try bigger recording
depths.
Rob
On Tue, Mar 12, 2024 at 5:13 PM Marcus D. Leech patchvonbraun@gmail.com
wrote:
On 12/03/2024 16:11, zackkomo@utexas.edu wrote:
Hey Rob and Marcus,
Thanks for the responses! I have a basic understanding of linux, but am
not very experienced. I tried the following to create the RAM filesystem:
sudo mount -t tmpfs -o size=8G tmpfs /mnt/tmpfs/
sudo mount -t ramfs -o size=8G ramfs /mnt/ramfs/
And ran the rx_samples_to_file, once with --file /mnt/tmpfs/test.bin, and
once with --file /mnt/ramfs/test.bin, both times still getting o’s for
overruns.
By my calculations, at ~500 M complex samples per second, each complex
sample 4 bytes (defaulting to short for I and Q), that means just 1 second
of capturing equates to 2 GB of data. My system has 64 GB of RAM. Am I
creating the RAM filesystem correctly? Am I using it correctly?
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Assuming that you did a "sudo mkdir of /mnt/ramfs" beforehand, this
should work.
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On 12/03/2024 17:59, Rob Kossler wrote:
I think I am mistaken. If you are only streaming a single channel, the
--multi_streamer option will likely not change a thing. I was assuming
you had multiple channels.
Rob
Indeed, the problem doesn't appear to be "getting samples off the wire
and into the application" (as evidenced by
the benchmark_rate runs), but rather "doing things with those samples
after that".
Writing 2Gbyte/second through the filesystem interface to the kernel
is....challenging.
On Tue, Mar 12, 2024 at 5:40 PM Rob Kossler rkossler@nd.edu wrote:
Your mount command with tmpfs looks correct. Here is what mine is
in my /etc/fstab file (with 264GB avail RAM)
tmpfs /media/ramfolder/ tmpfs rw,nosuid,nodev,size=200G 0 0
You might want to try rx_samples_to_file with the --multi_streamer
option. I expect you will get better performance. Also, you can
take your RAM FS size higher from 8G to probably 60G if you want
to try bigger recording depths.
Rob
On Tue, Mar 12, 2024 at 5:13 PM Marcus D. Leech
<patchvonbraun@gmail.com> wrote:
On 12/03/2024 16:11, zackkomo@utexas.edu wrote:
Hey Rob and Marcus,
Thanks for the responses! I have a basic understanding of
linux, but am not very experienced. I tried the following to
create the RAM filesystem:
|sudo mount -t tmpfs -o size=8G tmpfs /mnt/tmpfs/|
|sudo mount -t ramfs -o size=8G ramfs /mnt/ramfs/ |
And ran the rx_samples_to_file, once with --file
/mnt/tmpfs/test.bin, and once with --file
/mnt/ramfs/test.bin, both times still getting o’s for overruns.
By my calculations, at ~500 M complex samples per second,
each complex sample 4 bytes (defaulting to short for I and
Q), that means just 1 second of capturing equates to 2 GB of
data. My system has 64 GB of RAM. Am I creating the RAM
filesystem correctly? Am I using it correctly?
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Assuming that you did a "sudo mkdir of /mnt/ramfs"
beforehand, this should work.
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