RAM Disks - Making the most of a Power PC

This article was inspired by my colleague here at PantherProducts (look out for Neo_Angelo in the Forums) in the way that he is currently building a power PC with as much memory as he could possibly fit in it. My initial though was this is a waste as very few programs are going to get any where near the planned 32GB of RAM that is going to be inside this machine, even with video editing 32GB is a lot of RAM. Then I thought what could be a perfect solution - The RAM Drive. Those of you unfamiliar with the concept of a RAM drive, its basically a normal storage drive that shows up in windows as an extra drive but it is housed completely in the systems RAM. When you shut down the PC, the contents are copied to the hard drive, and when you start it up again its re-loaded into RAM. The only requirement is a piece of RAM disk software, which you can obtain for free by using a program such as DataRAM RAMdisk (Up to 4GB disk sizes, larger disks require a license fee).

Benefits of a RAM Disk

The is one major advantage to RAM disks that will bring many benefits to the programs or files that you choose to store in it. That advantage as you will probably know is speed. The systems RAM is many times quicker than a conventional hard drive because of the fact that an HDD uses mechanical parts and can never be as quick as the microchip. This means anything that would be loaded from the disk and is now loaded from RAM is going to respond much quicker. You can even set your internet browser to store temporary and cached files in the RAM drive which will speed up internet browsing as well. Another option would be to store a video that you might be editing into the RAM drive which would mean moving to different parts of the video would be speedy and every time you save it would be almost instant.

I already have an SSD will a RAM drive improve my system??

Solid State Drives or SSD's have been introduced as a replacement or more likely at the moment as an addition to the standard hard drive. Solid State Drives work on the flash memory technology which is much faster than the traditional hard drive also. So the improvement of a RAM drive over an SSD is obviously a lot less than that over a hard disk drive. However SSD's do have one small disadvantage and that is they have a limited life, they are not best suited to constant read and write to the drive. They are perfect for boot devices and storing files that will load fast. But if we take the example from earlier about using it to store cached internet files which will constantly change and be read multiple times, this would cause wear on the drive and reduce its lifespan. A RAM disk is this instance would be the better option.

Disadvantages of a RAM Drive

The Obvious problem here is of course that any system memory you put aside to use as a RAM drive can not be used in ordinary memory tasks for your PC. Because of this you have to be very careful not to degrade your systems performance too much by having a RAM drive that is too large and leaving your system with not enough memory to do the tasks. If this happens you will see Windows or other operating system start to use a swap file on the hard drive as make shift memory and completely sloe down the system operations. Also don't think you can change the location of the swap file to the RAM drive because this would completely be against the point as leaving the RAM available to the system would stop the swap file use anyway.

A less obvious disadvantage and one that often gets overlooked is the fact that RAM is volatile, by this I mean it does not retain the data that is stored on it once the system looses power. So every time you power down the PC the RAM will no longer contain what you stored in it. To get round this problem RAM disk software copies the data to hard drive before shutdown and then copies it back to the RAM once the power is returned. Sound simple enough but if you are having a reasonably sized RAM disk, this process can add a fair amount of time to your shutdown and startup routines. Running and storing this data however from an SSD can negate this problem as the SSD can read and write this data much faster than the hard drive. If you are building a power PC with spare RAM for a RAM drive then chances are you have included an SSD in there, if not I seriously suggest looking into integrating this into your system.

How much RAM should I use for a RAM Disk??

This is down to what you need the RAM disk for and how much total system memory your PC has. Each machine will be different as they are used for different things and so how much RAM you require to be left will of course change. Firstly though I would not create a RAM disk much larger than what you need it for, you can always increase it later and any unused space on a RAM disk is simply a wasted resource. Then if you find you want more you can experiment in increasing the size of the RAM drive and monitor the system performance, you will soon tell if your system is struggling for memory as the hard drive will be constantly in use and applications will begin to slow down. The best idea of course if you already have a system that's running fine is to expand your systems memory where possible and use the expansion as the RAM disk. This way you will know the system will still be running fine and you know the amount of RAM you have purchased can be safely used for RAM disk purposes.

Would running games from a RAM disk improve its performance?

Only for very small parts of it, the limiting factor for most games is normally the rendering speed of the graphics card. Games these days are well optimized to use available RAM, so what you gain from putting the game into a RAM disk, you may well lose by not having that RAM available. It may help with the speed in which the game loads levels and texture packs that would be normally loaded from disk, but to be honest a decent SSD would be a better option in this case than dedicating RAM to a RAM disk. This isn't even taking into account that with a game the whole game will have to installed to the RAM disk on startup every time you boot up your machine, and copied back again on shutdown. I'm sure some minor improvements could be found by doing this but unless your in the situation where you have no SSD and you know that the hard drive is definitely slowing your game down I wouldn't bother with a RAM disk for games. Also on a side note If you are in this consideration, I would look at the way you have built your system with this much RAM to spare and no Solid State Drive, definitely look at building a more balanced system.