Install operating system on RAM?

That's not feasible and is not the way RAM works. The OS manages RAM. You don't "install" the OS in RAM. It's not permanent storage.

mfuchs88 said:

I know this is a very far-fetched idea, but I thought maybe, somehow, it might work. So I have 16GB of RAM in my late 2011 15" MBP and was wondering if anybody had ever managed to install their operating system on their RAM. I know that it would be weird and unnecessary, but why wouldn't it work? It would probably be possible if one could manage to find the RAM as a mountable drive. I'm just very curious about the idea and would love to hear everybody's thoughts on it. Even if some amazing computer genius managed to figure it out, it would probably be very very taxing on the RAM and kill it's lifespan among other negative effects, such as crazy overheating. Anyway, let the discussion commence.

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It's called a ramdrive. The main problem is that conventional RAM is volatile, turn off the power and all data is lost. Most ramdrive configurations require secondary storage for backup and retrieval, and optionally backup power supplies in the event of power loss.

This is wholly impractical for Macs.

It's certainly possible with consumer computers. Maybe not with Macs (not stating this as fact as I have no experience in this area) but I've certainly used ram drives on my computers in the past.

A far more practical solution is an SSD.

http://en.wikipedia.org/wiki/List_of_Linux_distributions_that_run_from_RAM

Can't be done with OS X though.

The thing is it's not really "installed", it's just run from your RAM and won't save information after a reboot unless you have another storage media.

What you can do however is create a RAM drive that is recognized as a secondary drive in OS X and you can boot apps from there with this app.

Of course it will eat your RAM so I find it pretty pointless given that you could simply close the window of an app without killing its process and it would do basically the same thing.

There are enterprise products currently on the market which allow for exactly what you're talking about. Similar products have been on the market in various forms since the 70's.

Knowing what RAM does, why can't you install the entire OS there?

I hear what you're asking.

Let's say I have 64 GB of RAM in my iMac. My OS with apps typically take up about 32 GB of space. If I were to install all 32 GB on my 64GB RAM, wouldn't that be hella fast?

I've always wondered the same thing. I think the challenge lies in why is RAM there? Which I don't know either. And what lead me to search for the answer.

I believe what the drive we call RAM does is clears itself every time you shut the computer down. Essentially tiding up the work space for the next days work.
If that is so, why couldn't you, for a day, install my entire workspace on the RAM?
I know it will delete everything upon restart. But imagine the speeds from the availability of having every app open in RAM and have 32GB of space left over.

PS.
I just realized that I'm replying to a post that was asked a year and a half ago.
I can tell a person in the past a bit about the future and with a better than average chance they'll reply. From a technological standpoint, that's amazing!

Older versions of Mac OS had a feature called RAM disk. Let you do exactly what you said: turn a part of your RAM into a disk.

Didn't affect the lifespan of RAM at all, no reason it would.

I think I remember stories of people getting RAM disks to boot? Regardless, no one ever really seriously used this feature as a disk that wipes itself when it loses power isn't very useful for much besides a scratch disk.

I think eventually we'll start seeing RAM and storage combined (maybe not for a few decades), but why not be able to address RAM and flash storage from eventually the same place? We've "borrowed" disk space for RAM before with virtual memory (managed by the OS), so I'm sure there could be some low-level way if manufacturers find it feasible.

It's funny you bring this up because it was talked about on the latest episode of ATP (about 2/3 of the way though):

http://atp.fm/episodes/46-a-compromised-machine

ecschwarz said:

I think eventually we'll start seeing RAM and storage combined (maybe not for a few decades)

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IBM System/38 circa 1970's/80's did exactly that. Trouble was they kept their file table in RAM so when they crashed they had to go and rebuild ALL their attached storage to find out where everything was. It wasn't unknown for that process to take 24hrs...then you could reboot

There is a place in the UK (of all places) that makes DDR2 (not 3) SATA II (not III) RAM disks. It's not totally cheap, it's ~$400.

Heck, they even have a separate power supply and a built in lithium battery so it will never lose power, plus automated backup from RAM to CF just in case you do lose AC power. Takes about 8-12 minutes.

Interesting - I do wonder why we don't see more of this with the low price of RAM. There's a lot of older systems that could really stand a boost from a bona-fide RAM disk.

Install enough RAM in your machine to leave the Apps up and running all the time. This will have the same effect as having a RAM disk. Configure the Apps to use a scratch disk on an SSD if you overflow the memory. I don't see how this would be any different than duplicating your apps onto a RAM disk.

You can use Activity Monitor to see how close your are to filling RAM. I have had Photoshop, Firefox, Excel, Mail, ViewNX, and Itunes all running under 8GB without overflow. My Mac Pro with 32GB never comes close unless loading a >4GB Photoshop file.

Some basic Linux operating systems copy themselves to RAM when starting. This is kept until they are shut down.

djtiek said:

I hear what you're asking.

Let's say I have 64 GB of RAM in my iMac. My OS with apps typically take up about 32 GB of space. If I were to install all 32 GB on my 64GB RAM, wouldn't that be hella fast?

I've always wondered the same thing. I think the challenge lies in why is RAM there? Which I don't know either. And what lead me to search for the answer.

I believe what the drive we call RAM does is clears itself every time you shut the computer down. Essentially tiding up the work space for the next days work.
If that is so, why couldn't you, for a day, install my entire workspace on the RAM?
I know it will delete everything upon restart. But imagine the speeds from the availability of having every app open in RAM and have 32GB of space left over.

PS.
I just realized that I'm replying to a post that was asked a year and a half ago.
I can tell a person in the past a bit about the future and with a better than average chance they'll reply. From a technological standpoint, that's amazing!

Click to expand...

The ram is there because it's crazy fast and because the processor can access it quickly.
Also ram doesn't "get cleared" it literally loses its data when it loses power. The shutdown process is basically, your mac scavanging the ram for any data that needs to be saved onto the hard disk.
In a way though everytime you boot your pc, mac osx get installed on the ram. All the neccesary files for the os to run get copied to your ram, it just loses them everytime you turn off your pc.