Odd question about bytes per reference.

[wyrd]

String str = null;

 

I forget how much memory a pointer takes.. is it 2 bytes? And 1024 bytes per meg right?

[Volte]

I'm fairly sure pointers are 4 bytes. And yes, 1MB is 1024 bytes.

[wyrd]

Erk. *grabs heart in near heart attack* 4?! :eek: Holy smokes. I thought pointers just stored a 16 bit address... it's 32? That's crazy.

 

EDIT:

 

Err.. and speaking of which..

 

bits -> bytes -> kilobytes -> megs -> gigs

 

I think we were both wrong. Wouldn't it be 8 bits to a byte, 1024 bytes to a kilobyte, 1024 kilobytes to a meg and 1024 megs to a gig. So 1,048,576 bytes to a meg.

 

In which case what I was worried about doesn't matter. I was worried about a large array of reference types taking up a huge amount of memory. But perhaps not;

 

Assuming 4 bytes per reference, that's 524,288 references per meg (1048576 / 4). What I was previously thinking was 256 references per meg (1024 / 4). *blink*

 

I guess I was worrying for nothing. ;)

Edited August 24, 2003 by wyrd

[Volte]

Oops I dunno what I was thinking....

 

1024^1 bytes = 1 KB

1024^2 bytes = 1 MB

1024^3 bytes = 1 GB

 

etc...

 

 

Also, you could be right about the 16-bit pointers.. I just thought pointers were 32-bit. 65535 bytes available for pointers just doesn't seem reasonable.

[wyrd]

Heh.. well I suppose this is what I get for not keeping the book I used in Assembly class. I'm sure someone will come along and set this whole thing straight. ;)

[aewarnick]

I sure hope so. I've been wondering the same thing. If it is just 2 bytes I'll have to change some of my code around.

[PlausiblyDamp]

Pointers should be specific to the OS architecture. In a 32-bit version of windows a pointer needs to be able to address 4G of ram - therefore 32 bits long.

[Hamburger1984]

...and the thing with storing a large amount of data in an array... why don't you use a MemoryStream - maybe it does what you're looking for?!

 

Andreas

[wyrd]

Pointers should be specific to the OS architecture. In a 32-bit version of windows a pointer needs to be able to address 4G of ram - therefore 32 bits long.

 

Ah, that would explain it. Gah, now I remember why I thought they were 16 bits. In assembly class we built programs built off of the 16 bit architecture to make things easier.