That is normal Windows behaviour: http://support.microsoft.com/kb/293215
You are not looking at "memory usage" but rather at so called "working set". It is built-in Windows strategy to trim application working set when its top-level window is minimized. That occurs with EVERY application run on Windows. Best regards, Tomasz Janeczko amibroker.com ----- Original Message ----- From: dingo To: [email protected] Sent: Saturday, December 06, 2008 6:24 PM Subject: Re: [amibroker] Re: Speed Issues TJ, I've been following this thread and experimenting with memory usage and noticed something I don't understand: With and IQ 1 min database and 500k bars (just an experiment) and > 500 tickers. I started a scan with wait for backfill and noticed the memory usage via Task Manager was increasing. I minimized AB and the memory usage immediately dropped t0 around 16 meg. Also I let it run minimized and the memory started increasing and then I restored it and minimized it again and it dropped right back to 16 meg. What's going on? d On Sat, Dec 6, 2008 at 6:25 AM, sidhartha70 <[EMAIL PROTECTED]> wrote: TJ, Thanks for your assitance here. As I explained the reason I made the number so large was to make sure I captured ALL of IQ Feed's 1 Min data AND daily data. I accept that I could have made the number 1mil instead of 2mil and achieved the same objective. However, for purposes of longer term intraday backtesting, I see no alternative other than to change the registry setting and load more bars than recommeneded. Anyway, this is all a learning process. Because most of us don't understand how AB manages data as intimately as you, we are not aware of how a larger DB critically effects performance (due to CPU cache being overloaded). Perhaps it's worth spelling this out a little more detail so that we are all 'in the know'. I have now decided to have one large DB for longer term backtesting where live performance is not critical... and a much lighter weight, smaller DB for live trading. Thanks again. --- In [email protected], "Tomasz Janeczko" <[EMAIL PROTECTED]> wrote: > > The original poster ignored recommended settings, ignored > warnings displayed by AmiBroker, used registry hack to > disable 500k bar limit and entered 20x more than recommended > "number of bars" for 1-minute IQFeed database (2 million bars instead recommended 100k) > > If you load 40 tonnes onto Ferrari it won't go. And that's no surprise. > > Always, I mean ALWAYS use recommended settings (as presented in tutorials > and videos) and it will work perfectly. > > As with any machine, any equipment, etc, if you load 20x more than manufacturer recommends > you can expect it to run at least 20x slower or not run at all. > > Best regards, > Tomasz Janeczko > amibroker.com > ----- Original Message ----- > From: "monitorit" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Saturday, December 06, 2008 3:34 AM > Subject: [amibroker] Re: Speed Issues > > > > Hi > > May I ask how many tickers are being continuously updated during live > > market hours? This would include the number of tickers that were > > exposed to an AA or were displayed on a chart since the current > > session of AB started + any additional tickers displayed in the > > realtime quote window (at least in my experience and with another > > data provider). Do you notice any problem after market hours when > > all the data is already local? > > I've given up trying to keep >30+ tickers live > > (with some days better than others.. ? d/t velocity of market > > activity or something else between AB -the internet - and my > > provider) but don't see a problem with chart redraws just the data > > update gets delayed. Even when I switch to a different ticker - > > redraw is quick - but the last bar can be several minutes old on a 1 > > min chart. > > > > Dan > > > > > > --- In [email protected], "sidhartha70" <sidhartha70@> > > wrote: > >> > >> Hi All, > >> > >> Just when I think I seem to have got to the bottom of speed issues > > for > >> live trading with AmiBroker... I find myself needing a little more > > advice. > >> > >> I have 4 charts... each chart has a total chart timing of about > > 0.045 > >> secs. > >> > >> However, the 4 charts in total, have a total redraw time of between > >> 0.5 - 0.65 secs. > >> > >> Does this sound reasonable...?? Not quite sure how we get 0.5 from > >> 0.045 * 4....? If not, any ideas where the extra redraw time is > > coming > >> from...? > >> > >> Second... I'm finding AB, again, very difficult to use for live > >> trading with this kind of redraw speed. What can I do to make it > >> faster...?? Any ideas....? (for reference ALL charts have the > >> following line at the end of their code, SetBarsRequired( 1000, > > 200 );) > >> > >> TIA > >> > > > > > > > > ------------------------------------ > > > > **** IMPORTANT **** > > This group is for the discussion between users only. > > This is *NOT* technical support channel. > > > > ********************* > > TO GET TECHNICAL SUPPORT from AmiBroker please send an e-mail directly to > > SUPPORT {at} amibroker.com > > ********************* > > > > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: > > http://www.amibroker.com/devlog/ > > > > For other support material please check also: > > http://www.amibroker.com/support.html > > > > ********************************* > > Yahoo! Groups Links > > > > > > > ------------------------------------ **** IMPORTANT **** This group is for the discussion between users only. This is *NOT* technical support channel. ********************* TO GET TECHNICAL SUPPORT from AmiBroker please send an e-mail directly to SUPPORT {at} amibroker.com ********************* For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: http://www.amibroker.com/devlog/ For other support material please check also: http://www.amibroker.com/support.html ********************************* Yahoo! Groups Links
