Installing Windows into RAM

[Blue Dragon]

Hey guys,

I've been reading a bit on the interwebs about people who managed to install their OS (WindowsXP) onto a Ram Disk which apparently resulted in a very good performance with fast loading apps ect.

I know it's pretty easy to load a live CD of knoppix into RAM before booting and having the same advantages (apps pop up instantly ect.) since there's already a simple menu option when booting the liveCD.

Now, I'd like to know if something like this is possible with windows. Nowadays you can easily buy 16GB of RAM for a couple of hundred $$$ which would be far enough to hold your XP or even Windows7. The only problem of course is that all the data is lost when you loose power. Well, not all is lost at once but it gets corrupted over time...

What I was thinking about is the following: Install Windows on a normal drive and every time you boot, copy the whole system into RAM before booting it up. That way the booting it self would take a little longer, since copying 5-15GB of stuff from a SATA-connection would take something like 5-10 minutes I guess, but once the system is up, your performance would be awesome, wouldn't it?

Later, in order to save your settings, installed programs ect., all you'd have to do is copy the system back onto the HDD before shutting down.

Would this be possible? I guess one could use a program like dd that just copies all the bits from one partition or even an image file to the RAM-Disk. What do you think? How would you do this?

Would you actually see the difference in speed when using the Ram for your OS as opposed to a normal HDD? Has anyone ever done this in this way? What about actually booting from the RAM-Disk? Does it show up as a normal drive in the BIOS or do you have a special boot loader on an additional drive?

Looking forward to your suggestions and answers.

EDIT:

Just found this: http://www.hyperdrive4.com/index.php Hold max 64GB of DDR2 Ram, but costs 400$ for the case alone, plus whatever 64GB of Ram cost. Not cheap, but 175MB/s read, 145MB/s write sounds pretty decent.

Edit2: Oh damn, Sparda just found the same thing. However, as I said it's not cheap. And if I already have tons of RAM in my system, can't I just use that?

[Sparda]

http://www.hyperossystems.co.uk/

[Webhostbudd]

Yea, I used to look at that. The only problem with the Hyperdrives(at least the ones I looked at), used old, more expensive DDR ram, and the enclosure was really expensive.

[Brian Sierakowski]

I think you might be better off just going with an SSD.

Same basic idea, but its persistent.

http://www.newegg.com/Product/Product.aspx...N82E16820167005

[Sparda]

I think you might be better off just going with an SSD.

Same basic idea, but its persistent.

http://www.newegg.com/Product/Product.aspx...N82E16820167005

and much slower, it's not really the same.

[moonlit]

http://hak5.org/forums/index.php?showtopic=11942 might be of some interest.

[VaKo]

You can get things like Gigabytes old iRAM drive which support DDR2: http://techreport.com/articles.x/16255. SATA interface to a 8 slot DDR2 5.25" unit, with battery and compact flash backup. Expensive, yes, but much faster than any SSD on the market, despite being limited by the SATA interface.

A much faster way would be to take a server with 32 GB of RAM, install linux then xen. Create a 20GB RAM disk, and create a VM inside that.

[Sparda]

A much faster way would be to take a server with 32 GB of RAM, install linux then xen. Create a 20GB RAM disk, and create a VM inside that.

I like that. You could even just create a ramdisk and share it using iSCSI or smb or what ever that allows you to make it appear as local storage.

but problems:

1Gbps ethernet = quite slow (it will still be faster than a hard disk)

Unless your BIOS supports iSCSI, you aren't going to install windows and boot it. If you BIOS supports iSCSI you must have a pile of spare money and you may as well go buy the hyperdrive and get the massive performance increase.

</problems>

I could see this been used in a (corporate/school) lab where disk access times on a particular application need to be fast and consistant. So they equip each machine with gigabit ethernet, and install a 10 gigabit ethernet card in a machine that has lots of memory. Get the gigabit switches with the 2 or 3 10 gigabit ports and it still been cheaper than buying hyperdrives for 20 machines.

The starting price on the hyperdrives are £200, so you'd have to get all that stuff for less then 220 * 20 (amusing 20 computers, each having 2GB of fast access disk) = £4400 for it to be economically better. However, you would have to spend far less then £4400 for it ultimately be better given the significantly worse performance over gigabit ethernet.