There is another method: "max cache size (MB)",
however it only applies when min. 11 symbols is reached.

You can run your windows with /3G switch in boot.ini
this will give you extra gigabyte of addressable space.

Best regards,
Tomasz Janeczko
amibroker.com
----- Original Message ----- 
From: "ozzyapeman" <[email protected]>
To: <[email protected]>
Sent: Friday, May 08, 2009 1:34 AM
Subject: [amibroker] Re: AB Crashes when switching symbols


> Tomasz - thanks for the reply.
>
> I am reluctant to use 64 bit AB only because I auto trade and last time I 
> read, people were having issues with AB 64 bit in this 
> regard, and I think you also mentioned to consider that package as still 
> experimental.
>
> On AB 5.25 32 bit, reducing max. symbols to 11 does not help in my case, as 
> the 11 symbols in memory are big enough to cause the 
> crash.
>
> Would it be possible in the next AB update to somehow allow the user to limit 
> the cache some other way, i.e. not based on number 
> of max symbols but on overall memory usage? It should automatically flush 
> data from the cache if it starts to approach overload.
>
> In the meantime, I will reduce the length of my historical data, and see if 
> that helps.
>
>
> --- In [email protected], "Tomasz Janeczko" <gro...@...> wrote:
>>
>> You simply forgot that Windows 32 bit limits applicaiton space to 2GB.
>> It does NOT matter how much you have RAM or page file,
>> as long as you run 32 bit app / windows , the application addressable space 
>> is 2GB
>> (or 3GB if running /3G switch in boot.ini)
>>
>> http://msdn.microsoft.com/en-us/library/aa366912(VS.85).aspx
>>
>> There is simply NOT enough memory.
>>
>> 1.25GB is size ON DISK.
>>
>> In memory you need way MORE because you need space not only for data,
>> but also for AFL arrays.
>>
>> Not to mention that Windows usually DOES NOT have that much
>> CONTIGUOUS memory available.
>>
>> Use 64 BIT WINDOWS and 64 BIT VERSION of AmiBroker instead
>> http://www.amibroker.com/x64
>>
>> or ... reduce amount of data if you want to use 32 bit win/app.
>>
>> By the way, this:
>> In-memory cache size (max. symbols):  20000
>> is completely over the roof.
>>
>> Set it to 11 if you want to use very long intraday histories, then AmiBroker
>> will flush unused symbols out of RAM.
>>
>> And ALWAYS the latest (i.e. 5.25) as it uses less memory.
>>
>> Best regards,
>> Tomasz Janeczko
>> amibroker.com
>>   ----- Original Message ----- 
>>   From: ozzyapeman
>>   To: [email protected]
>>   Sent: Friday, May 08, 2009 12:21 AM
>>   Subject: [amibroker] AB Crashes when switching symbols
>>
>>
>>
>>
>>   Recently I built up my database to include 12 Forex pairs with historical 
>> 1-min data going back 10 years or so on each symbol. 
>> The total size of the database is only 1.25 GB, which does not seem too bad.
>>
>>   The problem is that when I switch charts from one symbol to another, I 
>> notice that mem usage in windows task manager indicates 
>> that AB (Broker.exe) keeps growing by 150mb or so, each time I switch 
>> symbols, and does not go down. If I switch symbols 6 or 7 
>> times, AB finally crashes.
>>
>>   This is especially cumbersome when I want to Merge each symbol with the 
>> latest weekly historical data. After merging a few 
>> symbols, AB crashes.
>>
>>   I am running WinXP on a dual quad-core with 8GB RAM, with allowable page 
>> file up to 25 GB. The crashes happen on AB 5.24 and 
>> 5.25. I imagine the same thing would happen on 5.20 but I have not reverted 
>> that far back.
>>
>>   In AB, I have the following set in
>>
>>   Tools--> Preferences --> Data:
>>
>>   In-memory cache size (max. symbols):  20000
>>
>>   (Max MegaBytes):                                             1000
>>
>>   Number of bars to load:                                 100
>>
>>
>>   AB does not allow me to set max. symbols to any less than 10. I imagine if 
>> I could set that to 1 or 2, that would keep the 
>> cache sufficiently low in terms of memory usage.
>>
>>   So the question is - what settings do I need to set, in the Data tab or 
>> other tabs, in order to ensure less memory usage to 
>> avoid crashes? Again, I only have 12 symbols in the database, and I imagine 
>> many users out there have far more than that.
>>
>>   This problem is preventing me from trading more than a couple of symbols 
>> at a time, without running into crashes.
>>
>>   Any feedback greatly appreciated.
>>
>
>
>
>
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