RAM disk in OSX

[garfildo]

Is there a possibility to create a RAM disk in OSX? If yes are there any apps doings this?

Many thanks in advance for your answer

garfildo

 

[divibisan]

There's no way to do it in the system, but there may be some hack that lets you do it, but I dont know of any.

 

[dricci]

BSD-based systems don't support this. Never going to happen. Ever.

 

[Securion]

Why?

 

[Securion]

If an Amiga with Workbench from the 1980s could do it... Why cant a Mac with OS X do it?
Its the year 2002 and we cant get a RAM disk?

 

[dricci]

I've heard that it's because of the way BSD's handle ram. There's no way to set a "chunk" of ram to designate to an app. When an app loads, the system estimates how much it'll need and assigns that much to it. Then if it needs more, it gets more. If it's done with ram, it gets it taken away. Also, background processes that have already had a space in the ram may be shoved in the background and decided that it's not as important as the front task so some of that ram gets taken away even more, or stored on the hard drive's swap file until it's in the front again.

I think there's something in this process that makes getting a designated ram size impossible for a virtual disk because it would always be changing as it's needed or not needed. And if the system decides your Photoshop needs more ram than the not-in-use ramdisk, it'll take away space from that, thus trashing what was on it.

Somebody please correct me if I'm wrong. I'm far from a Unix expert, yet.

 

[chenly]

dricci, you've got the right idea. The upside of the way UNIX handles RAM is that you aren't strictly limited performancewise the way you were with classic Macintosh or the way Windows users still are (not quite the same, but the Windows implementation of RAM management doesn't work nearly as well as that of UNIX); the downside is that there is no way to set aside a particular chunk of RAM. Honestly, and I've always had as much RAM as my Macintoshes could hold, the only really useful application of a RAM disk I ever found was running SETI@home--it was MUCH faster when running on a RAM disk, but, in the cosmic scheme of things (horrible pun intended!), this one little use is, in my book, no great loss.