Not in the way you might think

May 31, 2008 07:13 GMT  ·  By

You might have heard about the legend of the RAM disk that could make any Mac faster just by assigning it to handle the cache of internet browsers or even run games from it. Well, it might have made quite a difference for little games that you would run on a OS 9 based Mac that had very little memory.

Nowadays though, when talking about computers that have over 2 GB of RAM each, a RAM disk might not be the thing that you were expecting a few years ago. You can move your Safari?s cache folder to a RAM disk but this will not actually make such a big difference mainly because of the shear speed that today?s computers are capable of.

Pros and cons

But what is a RAM disk after all? It is not a physical drive but a part of your system RAM memory that functions like a disk drive, with a very important advantage: faster access times compared to your hard drive.

Despite this, I?ve already said above, a RAM disk is not the Holy Grail of file storage and there are things that make it the number one public enemy to a lot of people. One of such things, and the most important by far, is that everything ? by everything I mean every 0 and 1 ? that existed on it before restarting the computer will be unavailable the next time you enter your OS.

Where does it go? Into thin air, to binary heaven or wherever RAM stored data ends up. The main idea is that the data stored in the RAM disk will be gone forever and nothing will bring it back. Nothing except for a group of determined Princeton scientists that are ready to freeze up your RAM memory and toy with it sucking up your 0s and 1s and doing whatever they want with it (but why would a Princeton researcher want to mess with your RAM anyway?).

Using a RAM Disk

The thing that you could do to benefit from the boost of write/read speed that a RAM disk is capable of is to batch process large quantities of files, edit large image files with image editing applications like Photoshop or even when having to work with huge spreadsheet files that contain vast amounts of data.

Using a RAM disk in such cases will automatically prove to be good to your workflow because of the very quick saving times and the enhanced access speeds to the data contained in the file(s) you are working with.

Another use for a RAM disk, besides super speedy saves, would be to ensure that your browser?s cache files will not get inside wrong ends compromising your security. The browser that I?ll take as an example in this article is Firefox and I?ll show you how to move its cache to the RAM disk so that everything will instantly vanish the moment you restart your Mac.

If you think that this can also be achieved by simply telling Firefox to clean up its cache, history and everything else on its Security tab, you?re actually wrong because the data recovery apps out there will disagree: everything that ends up on your hard drive and it?s not overwritten can be recovered. And where is the security in that?

And yeah, I know that Firefox running on a Mac is seen as blasphemy by some of you but I like my Firefox add-ons and there?s no chance Safari will support those in the near future, therefore Firefox it is.

Let?s go on with our cache. First, you will have to create a RAM disk (I?ll explain the actual way to create the RAM disk towards the end so bear with me and learn how to use it in the meantime) ? let?s call it TEST for now ? and then open Firefox. On the address bar enter "about:config" (without the quotes) and in the Filter bar write down "browser.cache.disk.parent_directory". If nothing appears below, don?t worry and just right click somewhere on the white space and select "New->String" from the menu that will appear.

In the form window that will appear, you will have to enter "browser.cache.disk.parent_directory" and as the string value "//Volumes//TEST//" (if you will decide to name your RAM disk some other way just put that name instead of TEST but be sure to write it down exactly because, as you might now, OS X is pretty sensitive).

Do not try to put simple backslashes in the value expression because the trick will not work and your Firefox cache will end up once again on your hard disk.

To test your new Firefox setup, just load a page and take a glimpse on your hard disk. If you see a directory named "Cache" over there, you?re set! The moment you will restart your computer, everything on that RAM disk will vanish and with it your Firefox cache will fly, too. Now that?s what securing your data really means.

Creating a RAM Disk

Having learned how to really use the RAM disk we?re about to create, let?s fast forward and enumerate the "complicated" steps that you have to go through to complete this task.

Step 1 ? Download and install

You have to go HERE, download Make RAM Disk to your Mac and install the app wherever you want (although everything will work fine even you may want to follow the Mac ethics that say the best place to do that would be /Applications ? a good tip to keep your Mac clean too ;))

Step 2 ? Run and setup

Before double-clicking on Make RAM Disk, you will have to hold down the Option key to be able to edit the settings you want the app to use when creating your RAM Disk. On the window that will appear, you will be able to set the name the RAM disk that will appear on your desktop will have and the exact size you want it to have. Do not forget to check the "Save settings for next time" box because, otherwise, Make RAM disk will use its default settings and will create a 64 MB RAM disk name "RAM Disk".

Step 3 ? Enjoy

The only thing left to do is to click the "Make RAM Disk" button and voila! You have your own RAM disk on your desktop to play with.

Working with a RAM Disk

Having created and already using a RAM disk, you may want to know other things related to the way one can handle such an illusive beast. First of all, if you want to get rid of it, you will just have to eject it like any other ordinary mounted disk ? by dragging it to the Trash or selecting it and holding down CMD+E.

The next thing you may want to know is how you can have your RAM disk automatically mount itself each time you login. The simplest way is to create it once using Make RAM disk, saving the preferences by checking "Save settings for next time" and adding the app to your Login Items in System Preferences.

In case you do want to save the contents of your RAM disk before shutting down or restarting your Mac, there is no other way to do it - that I know of - besides copying its contents on your hard drive and then move them back next time you login (I don?t really see why one would want to do that but here is the solution anyway).

One last advice if you decide to try it on your own Mac: don?t come back crying to me (or anybody else) if you save anything important on it and it vanishes because of power failure or your pushing CMD+E by mistake. Remember to save anything important to your hard drive because after a RAM disk empties itself, you will NOT be able to recover anything you had on it.

Photo Gallery (4 Images)

The Make RAM Disk app's icon
The Make RAM Disk interfaceThe Firefox Cache folder on the RAM disk
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