LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 11-02-2009, 06:59 PM   #16
r3sistance
Senior Member
 
Registered: Mar 2004
Location: UK
Distribution: CentOS 5.4, Mac OS 10.4 (tiger)
Posts: 1,005

Rep: Reputation: 79

Just for fun then, I guess I will answer these... in a very over technical way. Just incase this is homework, basically to a degree where any lecturer or teacher would smell the stink of cheating 5 miles off.

Quote:
Originally Posted by kaushalsingh View Post
i just want to know the proper working of RAM.

1. What is the technology used in it?
Well RAM itself is an array of capicitors, These work via holding a potential difference. Capicitors work by having dual coils that hold opposing eleterical charges to most effeciently hold a potential difference.

the capicitors in RAM itself are small and basic so they don't effectively hold a charge effectively for long periods of time, this is opposed to flash memory (also used in solid state hard drives) that uses the similar priniples but are able to hold their potential difference for vastly longer ammounts of time. As a result RAM is volatile memory.

Quote:
Originally Posted by kaushalsingh View Post
2. If user wants to see movie then how does it keeps the data from hard disk and show us
It keeps that data within the capicitors as given within the previous. You'd have to phrase this question much better for a better response.

Quote:
Originally Posted by kaushalsingh View Post
3. Is there any specific amount of space given to program when it runs if so who decides it?
There is no "specific" ammount of space a program is given as a program may not know how much memory it will need, a program is able to reserve memory however, memory limits and allocation are handled by the kernel, the kernel is also responsible for the maximum limitation of RAM that single process or application can have, this is more noticable in windows then linux and more noticable on servers then desktop. Certain OSs and certain Development Platforms contain garbage collectors that are responsible for finding memory no longer in use and freeing up resources, an example of such a platform would be Java.

Quote:
Originally Posted by kaushalsingh View Post
4. If we copy something from one drive to another then does it use RAM ?
Really depends on situtation, a generic copy will go via RAM, however more specific cases may not, in the case of rebuilding a RAID array, this will be handled via the raid controller, in a hardware raid this will not require the usage of RAM for any part of the transfer process. This question relies on exactly what the conditions of the transfer between the drives are and how the drives are mounted exactly.

Last edited by r3sistance; 11-02-2009 at 07:04 PM.
 
Old 11-02-2009, 07:30 PM   #17
onebuck
Moderator
 
Registered: Jan 2005
Location: Midwest USA, Central Illinois
Distribution: SlackwareŽ
Posts: 12,541
Blog Entries: 23

Rep: Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943
Hi,

Quote:
Originally Posted by r3sistance View Post
Just for fun then, I guess I will answer these... in a very over technical way. Just incase this is homework, basically to a degree where any lecturer or teacher would smell the stink of cheating 5 miles off.

Well RAM itself is an array of capicitors, These work via holding a potential difference. Capicitors work by having dual coils that hold opposing eleterical charges to most effeciently hold a potential difference.
Please include a transistor for each capacitor within the cell for the array.

Quote:
Originally Posted by r3sistance View Post
the capicitors in RAM itself are small and basic so they don't effectively hold a charge effectively for long periods of time, this is opposed to flash memory (also used in solid state hard drives) that uses the similar priniples but are able to hold their potential difference for vastly longer ammounts of time. As a result RAM is volatile memory.
'DRAM' Dynamic Random Access Memory must be refreshed before the cell decays below the stored charge. The transistor is used to control the charge on the cell's capacitor. 'SRAM' Static Random Access Memory has 4 transistors typically too store the memory cell information and does not require a refresh but does require power to retain the storage settings. 'SRAM' density is not as great as 'DRAM'.


Quote:
Originally Posted by r3sistance View Post
It keeps that data within the capicitors as given within the previous. You'd have to phrase this question much better for a better response.

<snip>
The cell charge is controlled by the transistor.

 
Old 11-02-2009, 07:32 PM   #18
smturner1
Member
 
Registered: Oct 2009
Location: MI
Distribution: Arch 2.6.35
Posts: 107

Rep: Reputation: 1
Quote:
Originally Posted by onebuck View Post
Hi,



That doesn't excuse the asking of a 'HW' question. If YOU want to learn something then some effort on your part must be made to gain the understanding in order get knowledge. To formulate a question to a forum and not your instructor with the intent of using the forum's replies doesn't do you any good nor society to support such actions.

So to excuse it because you did it just attempts to excuse your actions (guilty mind). It's just wrong, like cheating on a test.

If the OP had presented some information with a request as to clarify same then others could/should aid. But the OP does have the responsibility of including reference notes as to the source of supporting material.

I was not excusing anything. There is nothing wrong with a person asking questions to a community to help them in their quest for knowledge. However the issue resides in the fact of how the question is framed. For example, I have an issue with writing to a text file in vi. I tried to read how to get around it for 2 hours, but that was not my assignment. I had to write a shell script and once finished I tried to save and close it, but couldn't.

Should I have refrained from asking for help because of some ill conceived idea that you have that says I am cheating? I do not think so. Although if I ask you how to write the shell script, how to save it, and how to close it there is an issue.

Give people some slack, not everybody is as gifted in this area of IT as you. I am sure that your contributions are to both further the OS and the people interested in it. Right?

Just a couple of thoughts.

Blessings,
Shaun
 
Old 11-02-2009, 07:45 PM   #19
onebuck
Moderator
 
Registered: Jan 2005
Location: Midwest USA, Central Illinois
Distribution: SlackwareŽ
Posts: 12,541
Blog Entries: 23

Rep: Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943Reputation: 1943
Hi,

Quote:
Originally Posted by smturner1 View Post
I was not excusing anything. There is nothing wrong with a person asking questions to a community to help them in their quest for knowledge. However the issue resides in the fact of how the question is framed. For example, I have an issue with writing to a text file in vi. I tried to read how to get around it for 2 hours, but that was not my assignment. I had to write a shell script and once finished I tried to save and close it, but couldn't.

Should I have refrained from asking for help because of some ill conceived idea that you have that says I am cheating? I do not think so. Although if I ask you how to write the shell script, how to save it, and how to close it there is an issue.

Give people some slack, not everybody is as gifted in this area of IT as you. I am sure that your contributions are to both further the OS and the people interested in it. Right?

Just a couple of thoughts.

Blessings,
Shaun
If indeed someone is attempting to extend their knowledge then that is a separate thing as compared to someone who posts homework queries. Sure, if someone who has a HW question and presents the problem along with what they have attempted along with questions as to the immediate problem then I may give some aid or slack. That will depend on the composition presented.

But to pass forum queries as the HW solution doesn't gain that same person any knowledge. Heck, Frat 'crib' storage files have got many students through University but did that enhance their Knowledge? NO! As for questions or non-HW that's not the issue. I've done my share of assisting and will continue while I can. But I will continue to be against anyone who encourages the cheating on HW, testing or just un-ethical things of this sort.

Enough said by me on this issue.

 
Old 11-02-2009, 07:47 PM   #20
r3sistance
Senior Member
 
Registered: Mar 2004
Location: UK
Distribution: CentOS 5.4, Mac OS 10.4 (tiger)
Posts: 1,005

Rep: Reputation: 79
Quote:
Originally Posted by onebuck View Post
Hi,

Please include a transistor for each capacitor within the cell for the array.

'DRAM' Dynamic Random Access Memory must be refreshed before the cell decays below the stored charge. The transistor is used to control the charge on the cell's capacitor. 'SRAM' Static Random Access Memory has 4 transistors typically too store the memory cell information and does not require a refresh but does require power to retain the storage settings. 'SRAM' density is not as great as 'DRAM'.

The cell charge is controlled by the transistor.

Meh, Years since I have looked into this stuff... =P. But anyways, lovely little things capacitors.... what would we do without them...

Last edited by r3sistance; 11-02-2009 at 07:55 PM. Reason: meant without... not with. with we'd make RAM! or store eleterical charges!
 
Old 11-02-2009, 08:54 PM   #21
King_DuckZ
Member
 
Registered: Nov 2009
Location: Rome, IT
Distribution: Sabayon
Posts: 61

Rep: Reputation: 2
Wink

Come on guys, it took longer for you to write all those "meh I hate those asking for homeworks" than actually replying... I'm new around here, so I don't know in what measure you get asked this stuff: I hope that by answering I won't cause a massive invasion of pupils willing to finish their duties quickly!

I think the OP is pretty confused about what RAM really is, so I'll try to make it a bit clearer, if I can

Last time I studied RAM architecture the book spoke about latches and nands circuits. It wasn't too hard to understand, although this technology has been supersteded when humanity got rid of manual switches to set bits.
All I can explain is that a nand latch can hold a bit (1 or 0) as long as it's not instructed to change it - that is, RAM needs to receive electricity in order to keep data, and you can only access it while it's not receiving maintenance charge. So, I think you can safely imagine that a nand circuit receives a signal that won't alter its content, say 11, then the system can send a signal to either alter or read its content, then it needs to wait for another refresh cycle. I might be wrong on some part (hopefully not completely), so probably someone could explain you this point better than this.
Anyways there are whole books on the subject, so a quick post is far from being exhaustive!

Video reproduction strictly depends on the software used - ideally you will have a circular buffer being read continously - that is, an amount of reserved RAM being continously overwritten right behind the reading position, so that on the next round shown pictures will be different and you only need a small limited amount of memory to show even a huge movie (that's what the prechache 2 seconds option in WinAmp and other players does, set the size of the ring, and why when your player freezes you hear the same piece of audio over and over, the buffer is not being refreshed anymore!).
That's just the final step, and displayed frame often resides on video memory. However the process is much more complicated as compression is taken into account - you need a buffer for storing data being decompressed, likely some temporary storage for decompression and finally a circular buffer for final display. Also, streamed videos like those on youtube might only exist in RAM.

The amount of RAM a program can use - people will correct me if I'm wrong - depends whether your software is running in protected mode or not, at least on intel processors. Also, the OS is an important factor: apparently, even the latest Windows won't allow an application to use more than 4 GB, although they might be running as 64bit apps (for 32 bit applications, in normal conditions you can only address 4 GB, and that's the limit of a 32 bit value, 2^32-1).

During file transfer, as someone already said it depends: a "normal" copy will be composed of a program loading data into a buffer and dumping it somewhere else, while other methods only rely on the drivers themselves. I'm not sure about DMA transfers, I might say it only uses controller's cache, but you can double check on wikipedia. Anyways as an example I'm reasonably sure that Nintendo DS' DMA copy doesn't use anything else other than source and destination locations (which may be on the cartidge).

Anyways programmers rarely have to worry about how electronics actually work, unless there is a special need. Most of the time you ask for a buffer and you're happy with it - you don't even know if it's in RAM, swap, VRAM or aonly-god-knows-where (thanks to M$, we have loads of C# gurus delivering critical apps and not even knowing what a cache hit is).

Hope I was of help!

King_DuckZ

Last edited by King_DuckZ; 11-02-2009 at 08:58 PM.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Suspension to ram only works for short periods cyberfishee Linux - Hardware 2 08-14-2008 08:35 AM
Suspend to Ram: works for a short time Peter_halv Linux - Laptop and Netbook 0 12-21-2006 07:43 AM
Suspend to RAM works occasionally. notapplicable Linux - General 0 11-23-2006 12:11 AM
Recovery from suspend to RAM only works in X? bl0tt0 Linux - Laptop and Netbook 1 04-24-2006 04:40 PM
suspend to ram works at last!!!! jwn7 Linux - Laptop and Netbook 4 03-31-2005 07:42 AM


All times are GMT -5. The time now is 11:47 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration