Ramdisk

[alohascott]

Aloha
I just discovered ram disks and I am very impressed with the performance.

I just ran a complete windows 7 install in a virtual machine in about 1 minute.

I also ran hd tune and it shows performance numbers that blow my mind. 6000mb reads and 8000mb s writes
and that is running slow 1333 ram.

my ssd is doing about 250 mbs and my regular hard drive does 140 mbs

so my ram disk is running 24 to 32 times faster then my sata 3 ssd.

where can i find out more about this subject and also more about how to get the correct data on my ram disk to optimize speeds for the system?

I have an idea it might have something to do with mount points but i don't know too much about that.
and i am sure there is risk with that kind of messing around with things.

also let me say right now I understand there are risks involved in this type of thing and i am fine with that.
I am very interested in minimizing the risks but not interested at all in forgetting about ram disks altogether.
also I am in a different situation then most people because my current os that i use daily is on a virtual machine.
it only takes me a few minutes to back up the entire machine.
so if i loose my power or something else causes me to lose the ram disk
who cares?
i just go to my backup machine.
If I am really concerned about my data then i use another hard drive in my virtual machine and put all my data on that which will be located on a real hard drive and then just use the ram drive for the OS.
ok so i hope we can keep the warnings to a minimum here. Thanks in advance.


I have a few questions that come to mind right now.

how much difference does the speed of the ram make to ram disks?

is my ram disk running on 1600 ram going to be twice as fast as 800 ram or whatever the number is?
please for the answer to this question lets ignore the latencies and other settings and just talk about the speed.
I guess what I am trying to say is that if i optimize my rams performance will i see a 1 to 1 increase in the speed of the ram disk?

can i raid 0 a ramdisk for even more performance?
can it get any more risky oh no what if one of my ram modules fails or my system shuts down LOL

can anybody point me to current benchmarks for the different ram disk programs.

also I am using open suse at school and was wondering if there are ram disks for that.

so many questions!

also i have questions to do with how to get the largest ram disk i can.

is there such a thing where I can just boot up to a very minimal os that does not take much ram and then fire up a ram disk? and run a virtual machine? maybe i am thinking about linux or something or maybe i just need win xp.

ok i had better stop now

thanks

 

[Pyree]

1. I would guess it will be like normal ram usage. The more ram the better and faster ram don't always make noticeable improvement in real use.

2. I don't think so, it will still be running as dual channel ram raid or not.

 

[Hawkeye22]

Have you looked into gigabytes i-ram or i-ram box? These have a battery, so you don't have to worry about losing your data. There are youtube videos that show these cards in raid.

http://il.gigabyte.com/products/product-page.aspx?pid=2678#ov

http://www.amazon.com/Gigabyte-GC-RAMDISK-i-RAM-Hard-Drive/dp/B000EPM9NC

 

[sminlal]

It's all very nice to get extreme benchmark numbers from a RAM drive, but you really have to ask yourself what the actual problem is that you're trying to solve. RAM drives suffer from the huge issue that they loose all their contents when the power is turned off (except for packaged solutions such as those mentioned by Hawkeye22). This means that you have to first copy data from a standard drive into the RAM drive before you can use it. If you have plenty of RAM, Windows caching effectively does the same thing anyway. So the real-world performance benefits of a RAM drive really aren't all that huge, unless you have a very specific file you want to force into RAM even if Windows would otherwise have to flush it from cache.

 

[WyomingKnott]

I two-thirds agree and one-third disagree with my senior, sminlal. The main benefit of what you are doing, from my point of view, is that it is _cool_ and _fun_.

To specific questions: Even in synthetic benchmarks, you don't get a 1:1 increase in memory throughput with increases in speed. You _cannot_ ignore the latencies, as they apply to every single read.

RAID0 would be useless as Pyree points out; the two RAM drives would be competing for the same memory.

Hawkeye22 (also my senior), that amazing device has an SATA I interface. By the way, when I was younger I wanted a huge physical RAM drive with the same amount of HDD (Flash didn't exist yet) to back it up. Basically a hybrid HDD with 100% cache size, and RAM for cache.

How much memory do you have in that machine? My Win7 install is up over 20 GB. I don't even have room for that much RAM in my rig.

Finally, two potentially limiting thoughts. Even with Win7 running totally from the RAM drive, you are still actually running under the emulator. If the emulator has to go to the hard drive, then you get hard-drive sized delays. Plus, you have to load the RAM from the HDD first, which takes time. What part of a Win7 install took 1 minute? Did you have the install disk cached; I don't believe that a DVD player could read the necessary data in one minute.

Here is the most interesting discussion of RAM drive in SUSE that I tripped over: http://forums.opensuse.org/english/other-forums/development/programming-scripting/400339-creating-ramdisk.html

I would be very curious to know if you actually see a huge improvement in system responsiveness with this setup.

For minimal startup before you get to a RAM drive, you might try a dedicated virtual-environment package such as VMWare. Of course, it ain't freeware. Here's a post from someone who tried it: http://forum.ncixus.com/forums/?mode=showthread&forum=116&threadid=2302134&pagenumber=0&msgcount=0&subpage=1

 

[RetiredChief]

Ramdrive I've played with: http://memory.dataram.com/products-and-services/software/ramdisk
The program is free for creating a ramdive up to 4 Gigs. Above 4 gigs it's like 10-15 Bucks.

Set mine to 8 gigs, have 16 gigs of Ram (DDR3-1600 CL7) so 8 gigs is mostly unused anyway, but I can always exit it if need and return by reloading..

For Normal Home use.
(1) Yes benchmarks blow the doors off an SSD, both in Sequencial read/writes and small file random read/writes - acess time can not be measures as it is short, less than 1 nSec.
(2) Slows down Boot time because it has to recreate (read from HDD and to a lesser extent SSD) and shut down time as it writes everything to HDD/SSD.
(3) No to concerned about data loss as NONE of my computers have a problem with BSODs and power outages are rare (But also computer on UPS). Also you can set the "back-up" interval which will run in the background.
(4) Working on a daily basis with a large complex Spreedsheet, large video files and large jpeg/bitmap photos might be a good use. Not beg enought to work on blu-ray video files which are typically 14 ->40 gigs which is like putting 50 lbs of that smelly stuff in a 5 lb bag.
(5) have not tried to install an operating system as an 8->12 gig ramdrive is to small
(6) One of the few programs that memory speed/CL ratings affect. Not a 1 :: 1 by any means. Unless I swapped my memory - opps would have to Buy some slower RAM so can not answer.

 

[alohascott]

Aloha an Mahalo RetiredChief
I really appreciate getting some input from someone who has actually tried using ram drive. All of your comments are very useful.

regarding windows using 8gb ram I find it is usually a lot less than that and also having experience with virtual machines I can change the amount of ram and be back in windows in under a minute and I can tell you there is not much difference in how it runs for me when I allocate over 3gb, or maybe even 2.5 GB ram.

I actually discovered ramdrives when I submitted my benchmarks to a site called benchtown and then looked at the guy with the best benchmarks and I could see he had a ramdrive.
his score was three times higher than mine on essentially a very similar 2600k based system.
at that point the only other thing that could have made a difference was the video card he was using.
but I put 6850 in my system now so next time I will see how much difference that makes to the overall score.




anyway regarding windows managing ram effectively.
well I needed a good laugh so thanks.

but it's not even close. I never see more than a few gigs of ram being used.

and anyway the ability to decide what I think is the important data to have in ram to speed up my system is the key here.

maybe I chose the wrong data or maybe I get it right, I can see the results and change my approach.

I have no idea what windows thinks is important but the fact that my ram is not being used more than 20 percent indicates it's doing a poor job of deciding.

also the fact that you do not see much of an increase in speed when increasing your ram above certain low amounts confirms that.

regarding the size of ram vs. the size of windows.

I can create virtual machine based on windows that takes about 10gb of space using windows 7 lite versions and even less using winxp. after installing all my programs in (windows 7 lite) and that is a lot of programs it only grows to 12 gb or so. So it can be done, I am also quite sure that much of that junk in the windows directory is not being used and would love to find a program to show me how much the data in a particular folder is being used.

but I think a better solution and one I am looking into is getting a board with 6 or more ram slots.

the other solution would be to move only the most used stuff to the ram drive
and technically I don't know how to do it but I think it has to do with mount points and I will do more research on that.

also there is the option to just put programs that you are using on there also and some ram drives dynamically re-size so if I had less ram I might choose one of those programs.

Regarding testing the speed I got some 1600 ram today in the mail so I will compare that to 1333 and see how much difference it makes and get back with you guys.

 

[RetiredChief]

My first ramdrive was on my first Home desktop computer a 386 SX added a co-processor (Had a 8086 Laptop). Had a 1 meg of Ram. Created a ramdrive, SMALL comes to mind.
The Thing about it in thoes days if you turned system of, rebooted, or Lost power - Bam lost contents. But this computer had a Bug in it, if I rebooted I did not lose the contents. That is until I tried upgrading the bios - No Update file, had to replace the Chip. Recieved new CMOS chip installed - no workee. Ended up sending it back and the replaced the CPU (What else they did, don't know). Ramdrive was as it should be, gone on reboot.

I'll have to look to see if I have the bencheies for my system.

 

[alohascott]

no luck changing the ram settings
it did not seem to make a difference in the speed of the ram as reported by cpu z and also no difference in the speed of ramdisk

will try another board over the weekend

 

[RetiredChief]

You indicated that the ram speed was the same - You need to change in bios. Most Ram above 1333 will install as 1333 (The default value) unless you change it in bios. Most recommend changing manually, but on my two systems I had good luck just changing the BIOS to use XMP, profile One.

 

[alohascott]

I was trying it on a motherboard which i am not sure supports faster ram.
I have other systems I will try it on.

So can you tell me what is OC ram?
I understand OC chips is running the chip at above rated speed.
is OC ram the same thing?
can I take a 1600 chip and run it faster?

 

[alohascott]

I came home and my stuff was in the living room!

Will post something later.

now running an i3-2120 for the first time.

good bye I7-2600k you lazy bastard.

 

[alohascott]

oops
as far as i can tell
ramdisk speed is based on cpu
not ram speed
i only noticed a tiny difference when raising ram to 1600
but a very large difference when overclocking the I7-2600k

ordering a new server based rig now to continue testing.
not much use testing with current computers, but i will give my x4 955 a chance later.

 

[RetiredChief]

Thanks on the input on memory bandwidth - very little effect.

Can understand after program/friles are loaded, cpu is in controls of performance. The storage device, be it SSD, HDD or a Ramdrive read/writes times should be controlled by the storage device.

 

[alohascott]

I ordered another 2600k and 2500k to compare them and OC them.
I got a p67 pro board that supports very fast memory (2200) but I do not know if I am willing to pay the extra price for that memory. We will have to see if it goes on sale somewhere.

 

[alohascott]

well those orders did not go through and I have had a change in my situation.
I will try ram disk on my x4 955 and see how it does but I am not very impressed with how it runs on my i3 compared to how it was running on the i7

 

[alohascott]

Best answer selected by alohascott.

 

[Mousemonkey]

This topic has been closed by Mousemonkey