BradMacPro said:
As the current Power Mac G5 motherboards use PC3200 DDR400 SDRAM, if you checked Crucial's web site, you'd find that the largest capacity modules you can order, in pairs for the G5, are 2GB, not 4GB. With 8 slots, that's 16GB. At $900 each that's still rather expensive. Just for comparison, the 1GB modules are $182 How much RAM do you really need?
Depends on the application. If you're doing serious number crunching -- which runs the gamut from graphics work (especially at high resolutions) through to scientific modelling (weather, nuclear physics, etc.) -- then the more RAM you have, the happier you are. There are plenty of datasets out there that won't fit into the RAM in your typical PC, and when that happens, you get so much swapping to try to
make them fit, the work slows down to a crawl.
32 GB, for some applications, would be a godsend.
Frobozz said:
RAM drives, baby. RAM drives!
Like hell. To get good use out of a RAM drive, you need to set it up at boot time; figure out which files are going to be hardest hit; move them across from the hard drive; and then configure the application to use the RAM drive to access those files. And if they're working files that you need to save, you need to remember to copy them back to the hard drive when you're done.
In a few -- a
very few -- applications, this may be advantageous. However, with any modern OS (meaning anything based on Unix, and anything based on the NT kernel, including 2000, XP, and 2003), the OS will automatically use any excess RAM to cache files. Try this sometime: with nothing else running on your Mac, open up a terminal session, and run the command "time ls -R / > /dev/null". Note the times given, then run it again. You'll see a massive drop in the time taken. That's caching in action.
In the vast majority of cases, the OS will do a better job of figuring out what to cache and what not than you could with a RAM drive at your finger tips. In other words, you'd need to put so much time and effort into figuring out what's best to put on the RAM drive, you might as well just give it up and let the OS handle it all for you. In most cases, it'll do a better job than you. In the other cases, it'll be so close that it really doesn't matter.
RAM drives had their use back in the 80s, when the OSes in use -- Mac OS Classic and MS-DOS -- didn't have the smarts to use excess RAM in this way. They also have their use if you're still running, say, Windows 3.1, which runs far better with a swap file than without, even if you have gobs of RAM (so you make a RAM drive and fill it with the swap file...). Except for those fringe cases, I don't see it being worth while. Trust in the OS; it'll be good enough.
