Hello, 1. It is your call. 64-bit version is able to use more than 4GB of memory and is slightly faster. But only supports IB and IQFeed real time plugins.
2. Yes, both versions (32-bit and 64-bit) use same data files and you can use same database. Best regards, Tomasz Janeczko amibroker.com On 2010-07-20 13:33, sanjiv wrote: > Hello Mr. Janeczko, > > Though now all my machines are Win7_64, I am continuing with Ami_Pro_32. Does > the benefit you described below warrant that I should migrate toward > Ami_Pro_64 ? > > Further, will the AmiBroker Native database being updated via ASCII import be > compatible across Ami_32 and Ami_64 interchangably. > > With regards > > Sanjiv Bansal > > > > --- In amibroker@yahoogroups.com, Tomasz Janeczko<gro...@...> wrote: >> Hello, >> >> There is* no problem* with adding 1000 to positionscore. >> >> You are adding the same value to *all* positionscore numbers and by doing so >> you will NOT change the ordering (ranking) even if 8th significant digit is >> subject to standard IEEE 32-bit rounding, >> because larger number will still be larger after adding constant, no matter >> if result is rounded in 8th significant place or not. >> So it is irrelevant. >> >> Also, it is important to understand that AmiBroker AFL arrays use standard >> 32-bit floating point, recommended reading: >> http://en.wikipedia.org/wiki/IEEE754 >> >> The same is used by majority of T/A applications since there is really no >> point in wasting memory on more. >> Using 32-bit floating point has two main advantages: >> a) consumes HALF of memory required for doubles (this *is* important, more >> important that you think, because >> if you have for example 500000 bars, in floats it is 2MB and it fits into >> CPU cache, while in doubles it would be 4MB and >> may not fit into CPU cache). >> b) 32-bit floating point numbers can be computed much faster. It simply >> takes less processor cycles to compute 32-bit float than >> 64-bit float. 64-bit version of AmiBroker is going even further and is using >> SSE2 instructions. This means that vectors of 4 single-precision >> numbers are processed in parallel using single SSE2 instruction on SINGLE >> processor. >> This gives more speed on single core than achievable using multiple cores. >> >> Note also AmiBroker *does use double precision (64bit)* where it is >> necessary (for certain internal calculations) >> >> >> Best regards, >> Tomasz Janeczko >> amibroker.com >> >> On 2010-07-20 01:37, Paul D wrote: >>> >>> Oh whoops. Sorry - apparently I didn't read your question carefully enough. >>> Not sure how to solve the precision problem. >>> >>> Paul >>> >>> ---------------------------------------------------------------------------------------------------------------------------------------------------------------- >>> *From:* Herman<psy...@...> >>> *To:* bistrader<amibroker@yahoogroups.com> >>> *Sent:* Mon, July 19, 2010 3:19:01 PM >>> *Subject:* Re: [amibroker] Why does adding 10000 to PositionScore cause >>> problems? >>> >>> You are exceeding the 7-digit precision (32 bits?) of AmiBroker. >>> >>> herman >>> >>> *> I have an afl with PositionScore at 77.904854 for one >>>> ticker. PositionScore also has negative values for >>>> certain tickers for certain dates. So, I add 10000 to >>>> PositionScore as I want all PositionScore values to be >>>> positive. I do so as followings and notice that 77.904854 >>>> changes to 10077.90527. Happens to many tickers. Not >>>> what I expected. I expected values to increase by exactly 10000. >>>> PositionScore = rank; // 77.904854 is one value observed >>>> PositionScaore = PositionScore + 10000; // expect to get >>>> 10077.904854 but get 10077.90527 >>>> I know I am missing something with precision. I looked >>>> in help but could not find anything to help. Does anyone >>>> know what is going on and where in documentation? >>>> Thanks. >>> >>> >>>> ------------ --------- --------- ------ >>>> **** IMPORTANT PLEASE READ **** >>>> This group is for the discussion between users only. >>>> This is *NOT* technical support channel. >>>> TO GET TECHNICAL SUPPORT send an e-mail directly to >>>> SUPPORT {at} amibroker.com<http://amibroker.com> >>>> TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at >>>> http://www.amibroke r.com/feedback/<http://www.amibroker.com/feedback/> >>>> (submissions sent via other channels won't be considered) >>>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>>> http://www.amibroke r.com/devlog/<http://www.amibroker.com/devlog/> >>>> Yahoo! Groups Links >>> >>> >>> * >>> >>> * * >>> * * >>> >>> >>> >>> > > > > ------------------------------------ > > **** IMPORTANT PLEASE READ **** > This group is for the discussion between users only. > This is *NOT* technical support channel. > > TO GET TECHNICAL SUPPORT send an e-mail directly to > SUPPORT {at} amibroker.com > > TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at > http://www.amibroker.com/feedback/ > (submissions sent via other channels won't be considered) > > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: > http://www.amibroker.com/devlog/ > > Yahoo! Groups Links > > > >
