Question with RAM and ROM

[Guest MobileGadget]

As I understand it, ROM is where the OS and data is stored (permanent storage), RAM is for program execution (temporary storage), and my US T-Mobile SDA has 64MB ROM + 64MB RAM. Now looking under System Info:

Storage Memory: 19.94MB

Used: 16.55MB

Free: 3.39MB

Program Memory: 45.06MB

Used: 22.72MB

Free: 22.34MB

I am assuming that storage memory = ROM, and the OS took a big chunk of it, leaving only 19.94MB left, but what I don't understand is why program memory (RAM) is only 45.06MB, shouldn't it be 64MB? I find it strange that Storage Memory + Program Memory = exactly 65MB, kind of makes me think that my phone is using the 64MB of RAM for Program Memory -AND- Storage Memory... Can someone explain?

[Guest mikeeey]

As I understand it, ROM is where the OS and data is stored (permanent storage), RAM is for program execution (temporary storage), and my US T-Mobile SDA has 64MB ROM + 64MB RAM. Now looking under System Info:

Storage Memory: 19.94MB

Used: 16.55MB

Free: 3.39MB

Program Memory: 45.06MB

Used: 22.72MB

Free: 22.34MB

I am assuming that storage memory = ROM, and the OS took a big chunk of it, leaving only 19.94MB left, but what I don't understand is why program memory (RAM) is only 45.06MB, shouldn't it be 64MB? I find it strange that Storage Memory + Program Memory = exactly 65MB, kind of makes me think that my phone is using the 64MB of RAM for Program Memory -AND- Storage Memory... Can someone explain?

yea i wondered that once too. i just figured it this way...

if u get a 250gb hardrive for ur pc then its gonna say u have a 234gb hardrive. it might be similar with the RAM maybe?

or maybe the 19mb of that ram that it isnt showing could just be RAM that will always be used so it doesnt even show it. the other 45 is being used by windows and your apps

[Guest MobileGadget]

yea i wondered that once too. i just figured it this way...

if u get a 250gb hardrive for ur pc then its gonna say u have a 234gb hardrive. it might be similar with the RAM maybe?

or maybe the 19mb of that ram that it isnt showing could just be RAM that will always be used so it doesnt even show it. the other 45 is being used by windows and your apps

In the hard drive example, it's due to difference in measurement standards, OSes defines 1GB = 1024MB, and 1MB = 1024KB, true binary standards, but hard drive manufacturers defines 1GB = 1000MB, and 1MB = 1000KB, therefor, 250,000,000 / 1024 / 1024 = 238GBs. If the same logic is applied to our phones, 64,000 / 1024 = 62.5MB, so I doubt this is the reason.

[Guest awarner (MVP)]

The 45MB is what's left after the OS has taken it's chunk to be able to run.

[Guest MobileGadget]

The 45MB is what's left after the OS has taken it's chunk to be able to run.

I thought the 22.72MB "Used" ALREADY accounts for the OS execution (plus some other programs that I was running). It's around 18MBs "Used" right after boot up WITHOUT any other program running, which means it has to be the OS using those 18MBs, with around 27MBs of RAM free, so where did the rest go?

The reason I am so curious is because I would like to get A2DP + MS Voice Command 1.6 + WMP + omapclock to run at the same time, and there isn't enough free RAM to do that. I don't think haveing 2 apps + 2 services is too much to ask for...

[Guest MobileGadget]

Anyone?

[Guest ianmills]

I am assuming that storage memory = ROM, and the OS took a big chunk of it, leaving only 19.94MB left, but what I don't understand is why program memory (RAM) is only 45.06MB, shouldn't it be 64MB? I find it strange that Storage Memory + Program Memory = exactly 65MB, kind of makes me think that my phone is using the 64MB of RAM for Program Memory -AND- Storage Memory... Can someone explain?4

I noticed this too. I always wanted to post about this. Honestly, I think HTC (and all the other companies who sell this phone) have LIED TO US about the RAM/ROM on the phone. It looks like the phone only has 64MB of memory (RAM and ROM) and it uses the same chip to do both the RAM and ROM. We should ALL email HTC to ask about this. I don't like being lied to

edit:

HTC's American e-mail is [email protected]

I wrote them, you should too. As well, if you want more people to read this thread, please edit your message and change the title to "HTC lying about RAM/ROM specification???"

Edited January 19, 2007 by ianmills

[Guest stevenmu]

I'm not entirely sure about this, but I believe that "Storage Memory" and "Program Memory" are both RAM. Certainly on my old PDA which had 64Mb RAM, it had a slider that let me decide how much to allocate to storage memory and how much to program memory (which would be handy on a smartphone too, but haven't seen that functionality anywhere yet). I believe that when the phone cold boots, the OS and some programs get copied from the ROM into the storage memory section of RAM and then get run from there. That way for general usage the ROM is left untouched and is more or less hidden from the user (except of course when flashing a new OS to it or similar). This then means that no matter how stupid we are, what files we delete or what poorly written software we run, there's always a fresh copy of the OS in the ROM so we can just do a hard reset and everything will run like clockwork (again except when flashing to the ROM).

(I could be very wrong about that though so don't go deleting OS files just to test it out :) )

[Guest mikeeey]

on the htc hermes or cingular 8525 tho, isnt it 64mb of ram and theres 45mb to use? windows uses 19mb? so maybe its just smartphones that seem to have less, maybe windows takes up more memory. or maybe htc is lying about the memory but idk. cant the memory only goes up multiplied by 2? cuz u always notice, u only see 8,16,32,64,128,256,512,1024...etc memory cards. wouldnt this be the same for internal memory? so they couldnt have 45mb of internal memory could they?

Edited January 20, 2007 by mikeeey

[Guest MobileGadget]

I'm not entirely sure about this, but I believe that "Storage Memory" and "Program Memory" are both RAM. Certainly on my old PDA which had 64Mb RAM, it had a slider that let me decide how much to allocate to storage memory and how much to program memory (which would be handy on a smartphone too, but haven't seen that functionality anywhere yet). I believe that when the phone cold boots, the OS and some programs get copied from the ROM into the storage memory section of RAM and then get run from there. That way for general usage the ROM is left untouched and is more or less hidden from the user (except of course when flashing a new OS to it or similar). This then means that no matter how stupid we are, what files we delete or what poorly written software we run, there's always a fresh copy of the OS in the ROM so we can just do a hard reset and everything will run like clockwork (again except when flashing to the ROM).

(I could be very wrong about that though so don't go deleting OS files just to test it out :) )

Your explanation makes sense, I have a PocketPC that is like that, both storage memory and program memory are stored in RAM, including the OS, where OS files can be deleted, but there is another backup of the OS that's stored in ROM, and if I ever need to, I can hard reset and it would make a fresh copy of the original OS from ROM to RAM, so it doesn't matter if I deleted any OS files, it's all back again.

If this is the case, then a lot of the ROM space isn't even used.

My theory:

Storage Memory Used (from RAM i guess) is roughly about 16MB after a cold boot, and if I delete any OS files, this number goes down, so it must be the OS that's making up for most of this 16MB, therefor, the original backup of the OS (a restorable clone if u will) that's in ROM would be around the same size, leaving a huge chunk of the ROM space unused.

This is pretty crappy engineering if all of this is true, why make 64MB of ROM when only a small portion is used, and only make 64MB of RAM for everything else to share (OS, installed programs, ringtones, themes, and memory to run ALL that). A 128MB RAM and 32MB ROM would be a much better solution.

Edited January 29, 2007 by MobileGadget

[Guest DSF]

RAM = programs memory + storage

ROM = OS

on the ppc you can partitionate the ram memory between programs memory and storage memory (at least wm 2003 ppc edition is capable of this)...

programs memory = temporary memory used for opened appliction (also known as RAM)

storage = persistent memory

anyway, interesting how WM does share the ram with a persistent memory. it seems that it has multiple roles in comparison with the ram from pc (where the ram is cleaned up at every pc reset /start)..?

[Guest MobileGadget]

RAM = programs memory + storage

ROM = OS

on the ppc you can partitionate the ram memory between programs memory and storage memory (at least wm 2003 ppc edition is capable of this)...

programs memory = temporary memory used for opened appliction (also known as RAM)

storage = persistent memory

anyway, interesting how WM does share the ram with a persistent memory. it seems that it has multiple roles in comparison with the ram from pc (where the ram is cleaned up at every pc reset /start)..?

That's what I was afraid of... 64MB RAM won't be enough for me to install AD2P + MS VoiceCommand 1.6 AND to run it to control song selections.

[Guest DSF]

how much space take those things? More than 10MB?

you cannot write in ROM just with special programs.. and it's a complicated process (see xda-developers.com)

and from the RAM module , ~ 16-17 is avaiable for Storage memory , the rest is avaiable for loaded OS, executed programs (processes).

[Guest MobileGadget]

how much space take those things? More than 10MB?

you cannot write in ROM just with special programs.. and it's a complicated process (see xda-developers.com)

and from the RAM module , ~ 16-17 is avaiable for Storage memory , the rest is avaiable for loaded OS, executed programs (processes).

I heard A2DP takes 20MB of RAM to run (from the A2DP pinned thread), not sure how accurate that is. MS Voice Command 1.6 takes another 10-15 MBs to control MP3s, and it differs from song to song, this is based on my own experience. So A2DP + MS VC already takes 35MBs of RAM just to run it, and I only have <28MB of program memory to start with.

I was reading about persistent memory, it states that data and storage are stored in ROM to save battery life, not RAM, and smartphones have adopted that since WM2002SE, and MS have mandated OEMs to do this on all WM5 devices, including PPC, now I am not so certain that my RAM is being used for program memory AND storage memory.