Improving PC speed with a RAM drive

[daqq]

Hi guys,

For an especially nasty piece of software I had to get some extra RAM, giving me a grand total of 32 GB of RAM. Now, most of the time I don't need it. So I was thinking of creative ways to use it.

I was wondering if anything I use might benefit from using a RAM drive. Xilinx stuff seem the most likely candidate seeing as their directories are chock full of stuff that is used during compilation. The same should be true for all sorts of other compilers (though I don't do anything too big with them). I don't do any serious graphics, but they would seem another likely candidate.

Has anyone tried this approach? What were your results?

Thanks,

David

[Rerouter]

For DVD authoring i found a significant improvement from having the source and destination as RAM, as with GPU rendering, the hard drive was the only bottleneck (something like 700FPS vs about 280)

For much else, not really, and windows 7 with a lot of memory, combined with intel's sata chipset read/write cache results in some funny quirks that come very close to mimicking a ram drive in the background, e.g. i cant explain why, but every time i copy a block of files smaller than the amount of free ram, the transfer rate will initially be the speed of my raid array copying to ram, then trickle off to the speed of wherever else the file is being copied, be it a usb thumbdrive or network, (580 MBps to a usb2 thumb-drive does seem a little impossible)

Other stuff i have played with is for panorama stitching, but i feel its really going to be situations where access time or hard drive bandwidth are the bottlenecks in the situation, and with compiling i cannot imagine there would be much going on after the files involved get pre-cached to ram,

[mariush]

I have 16 GB of memory and I installed Imdisk virtual disk driver ( http://www.ltr-data.se/opencode.html/#ImDisk , it's freeware ) to create 8-12 GB drives when I need them.

I work often with 6-8 GB archives that have loads of files (think 50-150k small files) and I have to search for keywords, phrases etc in them.  NTFS kind of sucks, it works faster to extract the archive to ram drive and do searches directly in RAM. I can configure the antivirus to disable scanning on the virtual drive so it wouldn't slow down searches, I can configure Windows to stop trying to cache content of the drive in memory (since it's already in memory), so searches are much faster.

[Kjelt]

You can use it for virtual machines, you can run multiple simultaneously.

[Howardlong]

Indeed, VMs are what my 16GB is there for.

For the file system, everythig apart from archive is on SSD, which makes global searching for files massively quicker.

[smjcuk]

SSD is probably as good as you're going to get on Windows.

You're probably stuck with NTFS which has some massive limitations with dealing with lots of small files on disk. They're all bunched up in the Master File Table which has to be locked and unlocked to do fragemented writes. This is a notoriously bad bottleneck. You can use fsutil to tune out some of this but that doesn't really make any difference worth mentioning (less than 20%). TBH RAMdisk suffers from the same problem as well as it's stuck behind the NTFS driver as well. The main problem is the locks are in kernel space so they have to be flushed to and from cache every time they are written and read to.

To give you an idea to check our master software platform out on disk from SVN takes 14 minutes onto NTFS and 2 minutes onto ext4 on a Linux box. The latter uses the entire outgoing network bandwidth from the server. The former is stick with a massive disk queue. Same hardware.

Windows = crap. Then again Linux is crap in other ways so we're screwed.

[amyk]

You can format RAMdisks with FAT32 too, unless you want to store huge (>4GB) files on them.

[ConKbot]

32 GB in my PC, and I made a 20 GB ramdrive, made a ntfs symbolic link to my steam directory, and moved crysis 3 to the ramdrive.  Loading times dropped from 20-30 seconds off of an SSD, down to to 10-15 seconds. Most of which was putting data into the video card. Everything else went fast, and then I'd watch the video card memory fill up, once that was full, the level was loaded.