Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order with a worst case performance of constant time.

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I have 16GB RAM. Do I need 32GB swap?

I read many places that the rule of thumb for swap space is to double the amount of physical RAM. However, 32 GB does seem a LOT. Do I need that much? Do I need it at all with this high amount of ...
69
votes
7answers
124k views

How can I monitor the memory usage?

I have used top to see the memory usage at the moment. But I would like to monitor the memory usage over a period of time. E.g start monitoring and then execute a few commands, and final stop the ...
56
votes
5answers
21k views

Drawbacks of using preload? Why isn't it included by default?

I would like to know what are the drawbacks of using preload? If there would be no downside, preload would be enabled by default, so I guess there are some. Okay you need a bit more RAM, but most ...
31
votes
4answers
36k views

How to check video memory size?

Is there a way to check the size of the video memory? Specifically, is there one that works accurately for both integrated GPU's as well as PCI/AGP graphics cards? Many integrated GPU's have ...
24
votes
5answers
16k views

Why does Ubuntu only show 3GB of RAM?

I have an Asus G50vt-x5 laptop with 4GB of RAM installed. But Ubuntu 10.10 shows only 3GB of RAM. Why is it only showing 3GB of RAM instead of the full 4GB? output of free command is : neal@ubuntu:~$ ...
22
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4answers
20k views

How to find the frequency and type of my current RAM?

How shall I find out the frequency and type of my current RAM? My OS is Ubuntu 12.04.
22
votes
2answers
11k views

'zeitgeist-fts' always using a lot of memory!

What is zeitgeist-fts?! It's always in the 3 top positions of memory usage (competing with Firefox and Compiz!!) ... After a fresh boot it uses about 30 MB, but after some hours or a day, it goes ...
21
votes
2answers
9k views

Memory limiting solutions for greedy applications that can crash OS?

I use my computer for scientific programming. It has a healthy 8GB of RAM and 12GB of swap space. Often, as my problems have gotten larger, I exceed all of the available RAM. Rather than crashing ...
20
votes
3answers
11k views

How to see the actual memory and its properties (slot position, size, speed…)

I have 2 PCs. A Laptop dv600 and an Intel dp35dp. I want a command that shows me how many slots of memory I am using, the size, speed, etc.. For the moment the size of each would be good. Maybe see if ...
19
votes
3answers
7k views

Why is Unity (Compiz) consuming more and more RAM? [closed]

About 3 to 4 hours after turning on my PC, compiz 'memory usage' rose from 300MB up to 1.5GB! What is happening? What is wrong? Here is the screen-shot from system monitor:
18
votes
6answers
3k views

8 GB RAM on 64 bit processor using 32 bit Ubuntu

I'm going to repeat the title in a longer word. Can a 32 bit Ubuntu address more than 4 gb of RAM on a 64 bit processor?
18
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3answers
23k views

What is a segmentation fault?

In Ubuntu I have faced the segmentation fault error many times. What is a segmentation fault and when does it occur?
17
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5answers
35k views

How can I check my RAM and hard drive for errors?

What tools can I use to check that my memory and hard drive are still working correctly?
17
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4answers
44k views

How do I clean or disable the memory cache?

After the system starts, in a few minutes my memory cache fills up and it starts using the swap. Here's a screenshot of /proc/meminfo. However, if I can disable this process / clean the cache once ...
17
votes
6answers
15k views

How to determine where biggest files/directories on my system are stored?

I was wondering how do you know where the largest files in my system are stored. For example--- Disk Space Used: 1GB Java: 500MB Java Percentage: 50% maybe represented in a pie chart. Maybe? I know ...
16
votes
2answers
3k views

Is it possible to query maximum ram my mobo takes?

Is it possible to query through Terminal how much ram my motherboard can take? I'm looking to see if i can even upgrade.
16
votes
6answers
60k views

What's the maximum amount of RAM I can use on an specific hardware

I've an Asus U31SD Notebook with an i5-2430M CPU. The Asus site says that the maximum RAM is 8 GB, but Intel's says my CPU supports 16 GB. What is the maximum RAM I can use on this system ...
15
votes
2answers
10k views

How to create RAM drive?

How do i create RAM drive under ubuntu. And would he automounted at startup?
14
votes
3answers
13k views

How to find how much RAM does my computer have?

How do I find out how much ram my computer has? I am running Ubuntu 13.04.
14
votes
4answers
9k views

Computer freezing on almost full RAM, possibly disk cache problem

The problem I think is somewhat similar to this thread. It doesn't matter if I have swap enabled or disabled, whenever the real used RAM amount starts going close to maximum and there is almost no ...
14
votes
2answers
4k views

Customizing Ubuntu to run from RAM only, within GRUB options

I'm interested in exactly this up, now let me explain what would like to do with this. I'm preparing to buy 32GB of RAM and already have Quad Core. My idea is to implement another option in GRUB that ...
13
votes
6answers
33k views

How do I find out if I have a swap partition on my hard drive?

I used the 12.04 live cd to install Ubuntu over my Windows 7 partition and deleted everything so I just have Ubuntu on my laptop. But since during the installer I chose the simple "erase entire disk" ...
13
votes
4answers
5k views

How to fully utilize RAM to increase overall system performance

I have a low profile machine but with a lot of fast RAM, 4 Gb, which is really an amount of memory that i probably will never use, not even an half, since i just use this machine for coding and ...
13
votes
3answers
7k views

How much benefit does increasing memory RAM have on the system?

I will soon have a PC that can handle up to 32GB of RAM (Yeah my dream comes true) but I would like to know, because this is the first time I am jumping the 4GB boundary on a home computer, how much ...
13
votes
1answer
1k views

How to tell what kind of RAM is used?

I recently added another RAM module and while it is supported by my motherboard I'm not quite sure if it's of the same type as the one my notebook shipped with. How can I tell what RAM modules are ...
12
votes
4answers
48k views

Why am I frequently getting this “Cannot allocate memory” error?

I'm using Ubuntu 12.10 with Gnome-Classic. I am getting this error frequently and with almost all programs, big and small. When I try to open them, they don't start, and instead I get an error message ...
12
votes
2answers
74k views

How much memory (RAM) should I allocate to the Virtual Machine?

I'm installing Ubuntu in a Virtual Box; my host OS is Windows 7, and I have 6GB of RAM on my system. One tutorial on setting up Ubuntu on a virtual machine (this one, on step 14: ...
11
votes
3answers
6k views

How to read correctly “free -m” output?

The output of free -m: total used free shared buffers cached Mem: 595 482 112 0 63 324 -/+ ...
11
votes
2answers
56k views

How do I change Java Runtime Parameters?

On Windows, I could change how much RAM Java could use by typing something like -Xincgc -Xmx2048M in the Java Runtime Parameters. How can I do that in Ubuntu?
11
votes
1answer
10k views

Why is Ubuntu 14.04 using too much RAM..? [closed]

Compiz in earlier versions of Ubuntu took around 60-65 MB of RAM. In Ubuntu 14.04, it is taking around 205-201 MB. And Nautilus took 35 MB of RAM in earlier versions, it is taking a minimum of 65 MB. ...
10
votes
2answers
3k views

How do I run memtest86+?

If I encounter a situation where I suspect my machine's RAM might be going bad, I might need to launch memtest86+ to check it. How can I do this using Ubuntu? Are there different methods for launching ...
10
votes
3answers
2k views

Lots of ram. How to use it?

My PC has 8 Gb of ram. Is there any way to make ubuntu use most of it? I mean rarely drop caches and keep once opened programms in ram longer, preload apps on boot, etc.
10
votes
5answers
12k views

How to permanently enable compressed ram swap? What version to use?

EDIT: In precise there's now zram-config. It's an upstart job compressing up to half of your ram spread over $(number of CPU cores) swap devices. It didn't allways start at boot but issuing sudo ...
9
votes
9answers
5k views

What are the available browsers for 128 MB of RAM PC?

Running 12.04 with VirtualBox and I set it for 128MB of RAM. I cannot use more than 128MB of RAM. Since the browsers I know like Firefox, Google Chrome and Chromium seem to eat more RAM, could ...
9
votes
2answers
21k views

How do I make a RAM disk?

I want to make a partition that is made of ram ... Example In windows 7 you can make a partition that is made of ram I have created 1 GB of partition in ram . using Primo RamDisk Is there any ...
9
votes
2answers
22k views

What is “cached” in the top command?

When running top, I get: top - 09:10:52 up 18:37, 1 user, load average: 1.56, 1.33, 1.15 Tasks: 39 total, 1 running, 38 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1%us, 0.6%sy, 1.0%ni, ...
9
votes
3answers
23k views

Why is the cache in my memory always full?

I have 6GB RAM, i5 2.4GHZ Processor running Ubuntu 11.10. I partitioned my HD so that I have 8GB swap. When streaming online or opening several tabs in Chromium I soon have 4GB Memory in the cache. ...
9
votes
4answers
22k views

Using usbdrive as ram in ubuntu

In windows it is possible to use usb flash drive as a virtual ram. I wonder if it is possible to do so in ubuntu? If it is, how could one do it? [Edit]: I mean Ready boost equivallent for ubuntu. I ...
9
votes
1answer
9k views

zram vs zswap vs zcache Ultimate guide: when to use which one

What the hell are they? how are they different (I've written my understanding in an answer below) In the Zswap system, when a page is evicted from the zswap to the actual swap is it stored in a ...
9
votes
5answers
77k views

MicroSD card is set to Read-only state. How can I write data on it?

I have a MicroSD card reader in my notebook. When I insert a MicroSD memory card into it, I can't write any data on it - it's read-only. The same thing happens when I try to do it under root. And I ...
9
votes
2answers
10k views

How can I dump all physical memory to a file?

I am using Ubuntu 11.10, and wish to simply know whether I can dump all physical memory and swap, as due to some kernel restrictions, I can't dd /dev/mem, even as superuser. Is there any workaround or ...
8
votes
6answers
41k views

Is there a program that tells ram usage? [duplicate]

Possible Duplicate: How can I monitor the memory usage? I have Ubuntu 12.4 LTS and I need a program that will be able to monitor my ram usage. Any suggestions?
8
votes
5answers
9k views

How do I check how much physical RAM I am using in GB or MB format?

How do I check my whether my Ubuntu is 32-bit or 64-bit and whether or not it is using full RAM? I'm concerned that because my system is 32-bit it isn't using the maximum OS-supported RAM. It says my ...
8
votes
7answers
2k views

Would adding more RAM increase my speed in Ubuntu, and how hard is this to do?

I've got a Compaq 6910p 14 inch laptop with 1GB RAM, 2.0ghz Core2Duo and a Mobility Radeon x2300. I was wondering if Adding more RAM would help my computer If I add RAM, will I have to reinstall ...
8
votes
3answers
15k views

For a 32-bit kernel, what are the pros/cons of PAE vs. non-PAE?

I am using Ubuntu 12.04 32-bit. My kernels are PAE kernels. I know these are the kernels we can use for 32-bit OS which have 4 GB RAM, to utilize all 4GB of RAM. My system is a 32-bit system. So I ...
8
votes
1answer
4k views

How large of a swap partition is needed to hibernate?

I've read this question, but it doesn't definitively answer my question. If I want my computer to be able to hibernate, do I need to have a swap partition as large as my RAM, or will Ubuntu wisely be ...
8
votes
1answer
4k views

Ubuntu detects only 3.2GB RAM on a 64bit OS [duplicate]

Possible Duplicate: Only 3.2 Gb of memory being used on a 64-bit system I have been running 64 bit version of 11.10 which was upgraded from 11.04 and wasn't a fresh install. I earlier had ...
8
votes
1answer
8k views

Only 3.2GB RAM (out of 4GB) usable on 64bit installation. Dell XPS 13 [duplicate]

Possible Duplicate: Why does Ubuntu only show 3GB of RAM? I bought Dell XPS 13 few days ago. Installed 64bit version of ubuntu, and changed kernel to: 3.2.0-29-generic ...
8
votes
3answers
3k views

Installation only recognizes 3 GB of memory after RAM upgrade [duplicate]

Possible Duplicate: Why does Ubuntu only show 3GB of RAM? I recently upgraded my system from 2 to 4 GB of memory. When I booted into Ubuntu, it's only recognizing 3 GB. I followed some ...
7
votes
4answers
701 views

Where has all the RAM gone?

I have 1GB of RAM, and when I run NetBeans and Firefox, they get about 300MB of RAM. At some point, the system becomes very slow, probably 100 times slower than normal, switching windows (Alt+Tab) ...