# High Data rate File Sink dropped data **URL:** \ **Category:** GNU Radio\ **Created:** [August 1, 2011, 5:01pm UTC](https://www.ruby-forum.com/t/high-data-rate-file-sink-dropped-data/210168 "2011-08-01T17:01:50Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\ **Post date:** [August 1, 2011, 5:01pm UTC](https://www.ruby-forum.com/t/high-data-rate-file-sink-dropped-data/210168/1 "2011-08-01T17:01:50Z")
I am trying to record data directly from a UDP stream to file. I have four channels at 1.2MHz sample rate the code is below. Basically it opens a UDP source and connects to a file sink. However, It is losing data when writing to the file. If I stream a signal with a one second burst the spacing is not correct. Also, I have another c++ program that reads the UDP packets and records directly to file, and there are no lost UDP packets nor lost data with this program. Also I have checked that the UDP packet size is less than 1472, it is currently at 1024 bytes. Is there a way to see if file\_sink is not able to handle that data rate, or to see if the UDP source cannot keep up? #!/usr/bin/env python from gnuradio import gr from gnuradio.wxgui import waterfallsink2, stdgui2, fftsink2,scopesink2 import wx from optparse import OptionParser from gnuradio.qtgui import qtgui import os import time import thread import threading class gnuradioGUI(stdgui2.std\_top\_block): def **init** (self,frame,panel,vbox,argv): stdgui2.std\_top\_block. **init** (self,frame,panel,vbox,argv) ``` self.sr = 1200000 self.channels = 4 self.FileLength = 5 #seconds of data in each file self.filenum = -1 self.baseName = "udp_1k." self.file_increment() self.ipAdd = "192.168.100.178" #the ip of this computer self.port = 3456 self.bufSize = self.channels*4096 self.signal = ``` gr.udp\_source(gr.sizeof\_short,self.ipAdd,self.port) ``` self.Update() self.thread = threading.Thread(target=self.FileThread) self.thread.start() def Update(self): self.lock() try: self.disconnect(self.signal,self.dest) except: print "could not disconnect" self.file_increment() self.dest = gr.file_sink(gr.sizeof_short,self.saveFile) self.connect(self.signal,self.dest) self.unlock() def FileThread(self): while 1: time.sleep(self.FileLength) self.Update() def file_increment(self): self.filenum = self.filenum + 1 self.saveFile = self.baseName + "%d"%self.filenum print "writing to file: " + self.saveFile ``` if **name** == ‘ **main** ’: app = stdgui2.stdapp(gnuradioGUI,“CAIS signal using GNU Radio GUI”) ``` parser = OptionParser() parser.add_option("-w", "--file", dest="filename", help="write data to FILE", metavar= "FILE") (options, args) = parser.parse_args() app.MainLoop() os._exit(1) ``` CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. ---
**Author:** ![jtoy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/f475e1/32.png) [@jtoy](https://www.ruby-forum.com/u/jtoy)\ **Post date:** [August 3, 2011, 2:12am UTC](https://www.ruby-forum.com/t/high-data-rate-file-sink-dropped-data/210168/2 "2011-08-03T02:12:55Z")
On Mon, Aug 1, 2011 at 10:24 AM, Jason T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > to see if the UDP source cannot keep up? > It’s most likely that your disk is not able to keep up. I’ve used GNU > Radio’s file sink to save gigabytes of data at 25 MHz float I&Q, but I > used a RAID5 device to do it. You probably need more spindles. Tom ---
**Author:** ![jtoy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/f475e1/32.png) [@jtoy](https://www.ruby-forum.com/u/jtoy)\ **Post date:** [August 3, 2011, 2:20am UTC](https://www.ruby-forum.com/t/high-data-rate-file-sink-dropped-data/210168/3 "2011-08-03T02:20:19Z")
On 08/02/2011 08:11 PM, Tom R. wrote: > > Is there a way to see if file\_sink is not able to handle that data rate, or > > to see if the UDP source cannot keep up? > > It’s most likely that your disk is not able to keep up. I’ve used GNU > Radio’s file sink to save gigabytes of data at 25 MHz float I&Q, but I > used a RAID5 device to do it. You probably need more spindles. > > Tom Tom: It’s not strictly disk-limited, since Jason observes that with a non-Gnu Radio program, he can record direct to disk from the raw UDP stream, and not lose anything. – Marcus L. Principal Investigator Shirleys Bay Radio Astronomy Consortium > **[Live Draw HK Tercepat | Result HK | HK Pools | Live HK | HK Prize Hari Ini](https://www.sbrac.org/)** > > Temukan live draw hk tercepat melalui halaman hk pools yang resmi dan dapatkan result hk prize melalui live hk secara langsung di situs kami. ---
**Author:** ![jtoy](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/f475e1/32.png) [@jtoy](https://www.ruby-forum.com/u/jtoy)\ **Post date:** [August 3, 2011, 2:23am UTC](https://www.ruby-forum.com/t/high-data-rate-file-sink-dropped-data/210168/4 "2011-08-03T02:23:24Z")
On Tue, Aug 2, 2011 at 8:19 PM, Marcus D. Leech [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > to the file. If I stream a signal with a one second burst the spacing is > > Radio program, he can record direct to disk from > the raw UDP stream, and not lose anything. Ah, I misread that. In my mind, he said something else… Still, I’ve never had an issue with the file sinks. More data is required. Tom