What is the Max size of Two Dimensional character array?

Question

I have one two dimensional array:

char[,] DataFile;

When I create a object:

DataFile=new char[45000,6000]

It throws an out of memory exception.

What is the Max Size of object in .Net 3.5? What Is the Max Length of char array?

I don't know, but I do know that what you appear to be doing (keeping a large file entirely in memory) is rarely what you need or want to do. I recommend you use IO streams to dynamically access and buffer the parts of the file you currently require. — Mels, Jul 04 '13 at 10:53
You are allocating about 1 GB of memory, on char is 4 bytes. — Casperah, Jul 04 '13 at 10:54
[Duplicate](http://stackoverflow.com/questions/1391672/what-is-the-maximum-size-that-an-array-can-hold) — Prahalad Gaggar, Jul 04 '13 at 10:54
Also, have you tried googling it? https://www.google.com/search?q=.net+max+object+size gives me loads of SO posts. — Mels, Jul 04 '13 at 10:54
possible duplicate of [Single objects still limited to 2 GB in size in CLR 4.0?](http://stackoverflow.com/questions/1087982/single-objects-still-limited-to-2-gb-in-size-in-clr-4-0) — Mels, Jul 04 '13 at 10:58
I read that In Net 4.5 we can allocate memory more than 2 gb Is It right? — Mahesh Chitroda, Jul 04 '13 at 11:34
@JeffRSon: Sorry, you are right, so the allocation is 500 MB then. — Casperah, Jul 04 '13 at 11:44
@Casperah: Maximum object size is 2 GB (prior to .NET 4.5), so the largest possible array of chars would 2^30 (a little more than a billion). Assuming, of course, that you could find a large enough contiguous block of memory (unlikely on a 32 bit machine). — Jim Mischel, Jul 04 '13 at 12:03
@MaheshChitroda How much available RAM do you have in your computer? — nmat, Jul 04 '13 at 13:07
@MaheshChitroda Do you have 2GB RAM available or 2GB RAM total? Run "Windows Task Manager" and see how much free memory you have before and after running the program. — nmat, Jul 04 '13 at 13:36

score 2 · Answer 1 · edited May 23 '17 at 11:56

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Single objects still limited to 2 GB in size in CLR 4.0? already has quite a nice explanation of the limits in various circumstances.

edited May 23 '17 at 11:56

Community

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answered Jul 04 '13 at 10:55

Mels

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JeffRSon · Answer 2 · 2013-07-04T12:16:58.657

Well, it depends.

Obviously it'll matter how much physical memory (RAM) you've got installed and/or how large you set up virtual memory (swap).

In any case, in 32bit Windows maximum object size is 2GB. But there's another limit: The process image must have a contiguous block of memory of the required size.

Your array is about 514MB large. You should check for yourself if you have sufficient resources available.

score -2 · Answer 3 · answered Jul 04 '13 at 10:55

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There is no actual limit, it just depends on how much RAM your computer has, and how much contiguous memory the runtime can allocate.

answered Jul 04 '13 at 10:55

Tamim Al Manaseer

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this is false please check source before posting – Rémi Jul 04 '13 at 13:26
I was answering based on ur current case, your not affected by the 2gb issue, and the array index length issue, so ur only limitation is ur own memory – Tamim Al Manaseer Jul 04 '13 at 13:46

What is the Max size of Two Dimensional character array?

3 Answers3