DTN IQFeed, DTN.IQ, DTN ProphetX Support Forums

Join the 80,000 other DTN customers who enjoy the fastest, most reliable data available. There is no better value than DTN!

(Move your cursor to this area to pause scrolling)

"Just a quick one to say I'm very impressed so far :) The documentation for developers is excellent and I've quickly managed to get an app written to do historical downloads. The system is very robust and pretty quick considering the extent of data that's available. The support guys have been very helpful too, in combination with the forums it's been plain sailing so far!" - Comment from Adam

"This is an excellent value, the system is generous (allowing for 500 stocks) and stable (and really is tick-by-tick), and the support is fantastic." - Comment from Shirin via Email

"Thanks for the great product and support. During this week of high volume trading, my QuoteTracker + IQ Feed setup never missed a beat. Also, thanks for your swiftness in responding to data issues. I was on ******* for a few years before I made the switch over early this year, and wish I had done it a long time ago." - Comment from Ken

"Thanks for all of your help. Great customer service deserves to be recognized which one the reasons I've been a customer of DTN for over 10 years!" - Comment from Stuart

"With HUGE volume on AAPL and RIMM for 2 days, everyone in a trading room was whining about freezes, crashes and lag with *******, RealTick, TS and Cyber. InvestorRT with IQFeed was rock solid. I mean SOLID!" - Comment from Public IRC Chat

"Everything is working great with the API. I love it." - Comment from Calvin

"I am enjoying the feed very much - so superior to the broker provided feed I was previously using." - Comment from George

"Everything is working great ! Very impressive client. The news refreshes better and is more pertinent than the ******* feed I paid $ 100/month for. I Also like the charts a lot." - Comment from Leon

"And by the way, have to say this. I love the IQFeed software. It's rock solid and it has a really nice API." - Comment from Thomas via RT Chat

"If someone needs the best quality data and backfill beyond what their broker provides at a rate that is the best in the industry, I highly recommend IQFeed." - Comment from Josh via Public Forum

Home

Recent Posts

Information on DTN's Industries:
DTN Oil & Gas | DTN Trading | DTN Agriculture | DTN Weather

DTN.IQ/IQFeed on Twitter
DTN News and Analysis on Twitter

»Forums Index »Archive (2017 and earlier) »IQFeed Developer Support »Issue with throughput

Author	Topic: Issue with throughput (3 messages, Page 1 of 1)
parallelguy -Interested User- Posts: 12 Joined: Feb 17, 2010	Posted: May 14, 2010 09:26 AM Msg. 1 of 3 IQFeed seems to be having issues sustaining communications above 930-1000 KB/sec and thus seems to be losing data during very high volume periods. I'm on a 22/6mbit cable modem, and have verified that I can sustain 22mbit speeds on both tcp and udp. I am subscribed to 576 symbols, which comprises of the S&P 500, some misc etf's and stocks, and the major futures. Regional updates are enabled for all stocks. I suspect this may be some sort of TCP window problem, as experimenting with TCP window settings on windows 2008 r2 does seem to measurably affect the peak rate I can get out of IQFeed. Unfortunately, none of them seem to perform better then the default settings. Any ideas what I might try next?
parallelguy -Interested User- Posts: 12 Joined: Feb 17, 2010	Posted: May 14, 2010 10:35 AM Msg. 2 of 3 Something else just noticed: IQFeed seems to be saturating one processor worth of CPU time when receiving 900+KB/s of data (8 core machine, 4gb of ram). Memory usage does not significantly fluctuate. Could this also be a problem? On Edit: To clarify, that is IQConnect.exe seems to saturate one core. Also, this is on 4.7.1.2 (beta). Edited by parallelguy on May 14, 2010 at 10:55 AM
David -DTN Evangelist- Posts: 113 Joined: May 7, 2004 I'd rather be...	Posted: May 30, 2010 05:54 PM Msg. 3 of 3 PG: FWIW: One thing that may give you some more information is to test the connection to your interface so that essentially there is no processing after each packet comes in - basically set a switch so that once quotes are coming in nothing is done with them and the socket is ready for the next data. Check out the CPU loading under this 'no loading' to see if better behaved. I suspect it may be very informative. I found that the processing time in servicing the stream by my program affects the CPU loading of IQConnect (and obviously my program). I also discovered that the 'message pump' should not be called within the event processing called from the OnDataAvail event notification. David *IQXP Software* http://www.iqxp.com LiveWire Update Service PO Box 1417 Fairfield, IA 52556 641-472-8393 http://www.livewire-cablesoft.com/