Could someone explain Ramdisk to me?

[dpk33]

From Google and Wiki, to me, it seems like a virtual SSD made from your unused RAM? Is there more to Ramdisk than that?

Let's say I get 16gb of RAM and my OS and programs use about 6gb max, what are some possible things I could do with a 10gb ramdisk?

Also, does faster RAM (e.g 1333 vs 1600) have an impact on this?

 

[BFG10K]

It’s virtual disk storage made from RAM whose contents are lost when the system’s powered down (though a hibernate may keep it). Every tech doc I’ve seen from Microsoft recommends not to bother as the Windows memory manager generally does a much better job overall.

 

[dac7nco]

It’s virtual disk storage made from RAM whose contents are lost when the system’s powered down (though a hibernate may keep it). Every tech doc I’ve seen from Microsoft recommends not to bother as the Windows memory manager generally does a much better job overall.

Yes and no. RAMdisks can be beneficial under some pretty unusual scenarios; Windows 7 and Server 2008 R2 use your available memory pretty wisely; if you're rocking 16+GB of RAM, you can get away without a SSD system disk a lot of the time on a production workstation. If you're doing some serious I/O with applications that routinely swap to disk (Adobe apps do this) no matter your memory capacity, a RAMdisk is beneficial. If you're running database apps at the end of a web server, with thousands of clients, RAMdisks are the shizzle.

One of the reason Adobe recommends you have separate swap disks for their production apps is because they don't use RAM wisely. I've never seen photoshop use 1/4 of a workstation's memory, but it'll sure swap the hell out of a RAMdisk. In that scenario, a RAMdisk is worth several SSDs. Workstations don't routinely have memory capacities of 96GB+ to run VMs; these are workstations, not servers. Flexibility is an issue, especially if your considering that 96GB of crazy-fast ECC memory @ $700 is often more viable than a few, slower, failable SSDs. There are people who swear, by the way, on RAIDs of 15K RPM spinning disks, for throughput. They are living in the dark ages. A RAMdisk is to SSDs as SSDs are to those disks.

Daimon

 

[corkyg]

Win 7 uses a RAM disk when it installs - but it is only temporary to support the installation. In today's world, a permament RAM disk is not necessary or adviseable.

 

[Mark R]

There's not that much use for RAM disks on modern systems.

They may still have use in niche applications, where you have software that requires rapid access to large amounts of data, but isn't able (or isn't designed) to hold it all in RAM, so saves temporary data to disk.

Usually, this means an old 32 bit program, that hasn't been updated to take advantage of 64 bit technology. Certain scientific and industrial programs can fall into this category. However, some software insists on having a "backup" copy of data on disk (e.g. some databases) so, directing this software to use a RAM disk avoids the overhead of actually accessing a disk (even an SSD). However, because the contents of a RAM disk are lost with power failure or system crash, you can't use this technique for storing valuable data - except on a temporary basis.

This type of RAM disk is not to be confused with enterprise RAM disks. These professional devices are basically huge boxes filled with RAM (up to several TB), a large backup battery, a set of backup hard drives, that connect to servers like an external hard drive array. Take the fastest SSD on the market and multiply it's speed by 40x and you'll be getting pretty close to the speed of this type of drive. Just be aware that if you have to ask the price, you can't afford it.

 

[Elixer]

Win 7 uses a RAM disk when it installs - but it is only temporary to support the installation. In today's world, a permament RAM disk is not necessary or adviseable.

While maybe not necessary, I don't see how it wouldn't be advisable.
With RAM being so cheap now, anything that is extremely I/O intensive greatly benefits from a RAM disk. Sure, the vast majority of the time, having a RAM disk is just for bragging at the insane speeds compared to SSDs or mechanical drives, but there are lots of programs that benefit from the speed.

 

[BFG10K]

While maybe not necessary, I don't see how it wouldn't be advisable.
With RAM being so cheap now, anything that is extremely I/O intensive greatly benefits from a RAM disk. Sure, the vast majority of the time, having a RAM disk is just for bragging at the insane speeds compared to SSDs or mechanical drives, but there are lots of programs that benefit from the speed.

The Windows memory manager always uses a RAM disk whenever possible. The difference is that a user’s RAM disk has its size and content manually managed by the user. Meanwhile the Windows memory manager dynamically adjusts the size and content as needed.

Except in some extremely niche cases, Windows will do a better job overall because it looks at the system as a whole.

 

[bryanW1995]

Excellent info BFG. That's a good reason to buy gobs of memory when it is as cheap as it is these days.

 

[kmmatney]

I use a RAMDisk along with my SSD, and have set windows to use the RAMDisk for temporary files. This is just to save writes on the SSD. I know I shouldn't have to worry about writes, but it's easy enough to set this up, so why not? A 512MB RAM Drive is more than enough for me or this purpose.

I also do a lot of programming and write a lot of log and debug info to the hard drive when testing software. By writing to a RAM drive while I'm developing, I save a lot of writes to the SSD. This is the most useful aspect of a RAMDrive for me. One software App has to combine thousands of X-ray image files into a AVI file, and I use a RAM drive for this. Very niche application...

I also once used the RAMDisk as the temp location for all files when using Chrome - this helps stop things like long-term Facebook tracking, but it was also annoying as you lose a lot of useful log-in information for frequently visited websites. I ended up going back to using the default Chrome data storage (although I still hate the Facebook tracking).