Dear all

Please help me, I have to create a lot of array of string on VB but I can't create it, the VB return the error that "out of memory", but I have 2 GB ram that it's enough to. Please help me how to create a lof of array. Thank you for your help

Best regard
tumarha

how long is the array

Ahmed Ali
Software Developer

The problem with re-dimensional arrays in VB is that when you first use them a block of memory will be allocated for it, then when you re-dimension the array the system will try to increase the size of the block of memory and will not use a new block of memory if you want to preserve the data already in the array. If the block of memory can not be increased to the size you require because there is another block of memory in the way, then you will get an out of memory error. Even though there is enough free physical memory, the block of memory being used can not be increased to the size you require.

First of all, are you re-dimensioning the array a lot? If at all possible re-dimension the array as infrequently as you can. What I will often try to do if I am increasing the size of an array in a loop for example, is to increase it by more than I need, then as the loop continues I will use the spare elements of the array instead of re-dimming the array again and again. Then if and when I reach the end of the array and still want to add more data I will re-dim it again by more than I need.

Secondly, can you use a static array? A static array will be much friendlier to your application, improving both performance and memory usage. This is because when your application starts the system will know how much memory is required for the array and it will know that it will never need to change this memory allocation.

Regards
Owain Williams

Dear Tumarha,

even if you have 10Gig of memory VB cannot use all of it, because VB, as any other programming languages, has its limitations. Please refer to the "Visual Basic Specifications, Limitations, and File Formats" section of the MSDN VB documentation.
Because of this, the code must catch and handle the 'out of memory' error. Keep in mind that using too much memory will snail the computer: memory usage (especially when processing lot of data) should be the first requirement when designing an application.

Marco

hi dear..

another idea.. i dont think any application with your requirements fits in VB.. maybe you need another language to do it??
anyway.. post more info about what are you trying to achieve.. maybe you are handling it in the wrong data structure...

Gonzalo Bianchi

Hi.
What OS you are using?
I use to have similar problem with VB6 and Windows 98. My array size was ~ 700 MB and 512 RAM. The error disappeared after moving to Win 2000 and XP. Don’t know why.

Pavel

The error disapeared because the virtual memory handling in Windows 2K and XP is much better than it is in 9x. Why on earth would you need an array that is 700Mb in size? As Gonzalo said VB is a rapid development tool, not a data cruncher.

Regards
Owain Williams

I am using VB with large arrays as well. I have a machine running vb6.0 with 2GB. It can't seem to dimension an array (using redim) any larger than 508MB. Anyone have any idea why this might be? The ram is configues as 4 512MB chips. Does this have anything to do with it, or does the physical separation of RAM not matter in terms of contiguousness.

hi all...
did you read all the thread??
why in the earth you have such array???

HTH

Gonzalo

It has been already mentioned that VB is not the best language for this work. But you may do so-so if you use the byte() type instead of string. But definitelly, you shuld use C++ and do all the memory allocation manually.

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