Questions tagged [ram]

RAM (Random Access Memory) is a form of computer data storage. A random access device allows stored data to be accessed in very nearly the same amount of time for any storage location, so data can be accessed quickly in any random order.

RAM (Random Access Memory) is a form of computer data storage. A random access device allows stored data to be accessed in very nearly the same amount of time for any storage location, so data can be accessed quickly in any random order.

The two main forms of modern RAM are static RAM (SRAM) and dynamic RAM (DRAM). In static RAM, a bit of data is stored using the state of a flip-flop. This form of RAM is more expensive to produce, but is generally faster and requires less power than DRAM and, in modern computers, is often used as cache memory for the CPU.

Both static and dynamic RAM are considered volatile, as their state is lost or reset when power is removed from the system. By contrast, Read-only memory (ROM) stores data by permanently enabling or disabling selected transistors, such that the memory cannot be altered.

2059 questions
23
votes
4 answers

How does random access memory work? Why is it constant-time random-access?

Or in other words, why does accessing an arbitrary element in an array take constant time (instead of O(n) or some other time)? I googled my heart out looking for an answer to this and did not find a very good one so I'm hoping one of you can share…
Kacy
  • 3,018
  • 3
  • 24
  • 49
22
votes
1 answer

Android memory types (RAM v Internal Memory)

On a separate thread I demonstrated my ignorance of memory types by asking about the best way to copy a file into "internal memory" and was advised that this was not a good idea and that it would be better to read the file into "RAM". I am now…
prepbgg
  • 3,454
  • 9
  • 35
  • 46
22
votes
7 answers

How much RAM is SQL Server actually using?

I am debugging one of my apps and noticed that the RAM on my SQL Server 2005 x64 box (running on a Windows 2003 R2 x64 ) is pegged and even going into the paging file. I understand that SQL Server 2005 x64 just grabs everything it can, so this…
AngryHacker
  • 54,471
  • 90
  • 289
  • 523
21
votes
10 answers

Why are 8 and 256 such important numbers in computer sciences?

I don't know very well about RAM and HDD architecture, or how electronics deals with chunks of memory, but this always triggered my curiosity: Why did we choose to stop at 8 bits for the smallest element in a computer value ? My question may look…
gokoon
  • 957
  • 2
  • 9
  • 14
18
votes
2 answers

Limiting node.js's memory usage

I am trying to limit a node.js application from using to much memory and I've found out about the --max-stack-size & --max_executable_size options that are available within V8 to pass when invoking the file, but how should I combine these and…
Industrial
  • 36,181
  • 63
  • 182
  • 286
16
votes
2 answers

How can I ask windows about if the RAM is running in single, dual or quad channel?

How can I detect the current RAM config? I need to ask windows about if the RAM is currently running in single, dual or quad channel. I have searched a lot, and not found any similar questions on this or other sites, which is quite surprising to…
JohnAl
  • 970
  • 2
  • 8
  • 13
16
votes
3 answers

How can I add memory to an Azure virtual machine?

Is it possible to add a "custom" size memory to an Azure virtual machine? For example, I'm using the Medium size - 2 core, 4GB RAM, I would like to have 8GB RAM with the current settings I have... otherwise the next option available is A5 2 core…
Yovav
  • 2,201
  • 1
  • 24
  • 42
15
votes
1 answer

We need to preallocate. But MATLAB does not preallocate the preallocation?

While testing if any() short-circuits (it does!) I found out the following interesting behavior when preallocating the test variable: test=zeros(1e7,1); >> tic;any(test);toc Elapsed time is 2.444690 seconds. >> test(2)=1; >>…
Ander Biguri
  • 32,737
  • 10
  • 68
  • 106
15
votes
19 answers

Will multi threading provide any performance boost?

I am new to programming in general so please keep that in mind when you answer my question. I have a program that takes a large 3D array (1 billion elements) and sums up elements along the various axis to produce a 2D array of a projection of each…
Faken
  • 9,902
  • 16
  • 55
  • 72
14
votes
6 answers

AndroidStudio show usage of RAM

I have seen on other AndroidStudio-pictures, that there is a RAM usage at the right bottom. I tried to setup this statuslist o the bottom. But a rightclick didn`t help me. How can I switch on the RAM usage in AndroidStudio ?
noobee
  • 163
  • 1
  • 2
  • 10
14
votes
2 answers

Data size in memory vs. on disk

How does the RAM required to store data in memory compare to the disk space required to store the same data in a file? Or is there no generalized correlation? For example, say I simply have a billion floating point values. Stored in binary form,…
14
votes
8 answers

how to keep c++ variables in RAM securely?

I'm working on a C++ application which is keeping some user secret keys in the RAM. This secret keys are highly sensitive & I must minimize risk of any kind of attack against them. I'm using a character array to store these keys, I've read some…
Ehsan Khodarahmi
  • 4,390
  • 9
  • 57
  • 81
14
votes
4 answers

If RAM isn't a concern, is reading line by line faster or reading everything into RAM and access it? - Python

If RAM isn't a concern (I have close to 200GB on the server), is reading line by line faster or reading everything into RAM and access it? Each line will be a string of around 200-500 unicode characters. There are close to 2 million lines for each…
alvas
  • 94,813
  • 90
  • 365
  • 641
14
votes
2 answers

What will happen,when mongodb db size will be times > then RAM?

Will it get slower? Will find work for only data that fit into RAM? What will happen if mongodb indexes are more then RAM?
SomeUser
  • 2,433
  • 13
  • 41
  • 57
13
votes
2 answers

Why isn't RAM as fast as registers/cache memory?

Why do we need to cache in Cache Memory? Why cant RAM Memory be made as fast as register or Cache Memory or Cache be as large as RAM Memory (4GB) so that everything can be in cache? Any good article/books to understand these concepts?
Andy
  • 131
  • 1
  • 3