memory just doesn't add up

[denasqu]

Okay then... I've been cooking my own ROM's and I thought I understood the memory availability and usage of the Verizon XV6900, but now I'm not so sure.

I've read that there is 128 MB of RAM and 256 MB of flash ROM on the XV6900 which equals 384MB in Total.

Settings/Memory says there is 138.02MB Storage memory availabe + 100.87MB Program memory available which equals 238.89MB total memory available. I always thought these numbers were all RAM, but obviously they can't be because I've only got 128MB or RAM to begin with. So what memory is this?

Next, I'm assuming that when I install a program via OEM that it gets installed to ROM and when I install it via CAB/EXE that it gets installed to RAM. If so, can my NBH file be up to 256MB? Will all my RAM be free for running programs and storage then? I doubt this is the case but I'm not sure why it isn't. If it's not, then how big can an NBH file be?

Lastly, is there a way to see memory usage/availbility of ROM only? ...of RAM only?

[gguruusa]

Originally Posted by denasqu

Okay then... I've been cooking my own ROM's and I thought I understood the memory availability and usage of the Verizon XV6900, but now I'm not so sure.

I've read that there is 128 MB of RAM and 256 MB of flash ROM on the XV6900 which equals 384MB in Total.

Settings/Memory says there is 138.02MB Storage memory availabe + 100.87MB Program memory available which equals 238.89MB total memory available. I always thought these numbers were all RAM, but obviously they can't be because I've only got 128MB or RAM to begin with. So what memory is this?

ROM + storage + some other stuff = flash = 256MB
program memory = RAM = 128MB

Next, I'm assuming that when I install a program via OEM that it gets installed to ROM and when I install it via CAB/EXE that it gets installed to RAM.

No. None of it gets installed to ram. You install to flash (storage). When you run applications, that's when they consume RAM.

If so, can my NBH file be up to 256MB?

technically, almost but not quite. Check out Nex's 180MB monster ROM - that's about as big as is feasible.

Will all my RAM be free for running programs and storage then? I doubt this is the case but I'm not sure why it isn't. If it's not, then how big can an NBH file be?

Lastly, is there a way to see memory usage/availbility of ROM only? ...of RAM only?

To see availability, which is kinda the only thing you need to know, just use the memory applet in settings/system. To determine usage, you need to know the size of partitions and subtract what is free.

[denasqu]

Thanks. So in a nutshell... when I look at Settings/Memory the Program memory available is RAM? ... and Storage memory available is ROM?

I guess I'm still a little hung up on WM5 and the dynamic slider they had to re-allocate Program memory v. Storage memory.

And I guess the difference between what Settings/Memory says I have to start with and what is physically in the XV6900 is due to the BIOS (or whatever it may be called in the PDA world).

For example:

Physical ROM in the XV6900 = 256MB
Settings/Memory/Storage is
Total: 137.40MB
In Use: 40.76MB
Free: 96.64MB

Obviously, 40.67+96.64=137.40.
But I started with 256.
So 256 - 137.4 = 118.6MB which would be the amount of ROM used by the BIOS, OS, and my startups ?


So is there no memory advantage to installing programs via ROM updates vs. CAB/EXE installs?

[gguruusa]

some...it's faster to install, survives a hard reset, customization can be baked in. Other than that, pretty much the same. Originally, rom sizes were fixed so it was a use it or lose it type situation. On modern devices, that's not true - unused rom space goes to storage.

[denasqu]

Originally Posted by denasqu

But I started with 256.
So 256 - 137.4 = 118.6MB which would be the amount of ROM used by the BIOS, OS, and my startups ?

Duh... I just figured it out. The missing ROM memory is actually holding the 80-100MB .nb files from my cooked ROM.

I can relax now.