21 replies to this topic

[Olof Lagerkvist]

I get an increasing amount of e-mail from people who have a too small amount of RAM in their computers and try to use ImDisk to create a "RAM disk" to get more "virtual RAM". Most of them create a hard disk partition or image file, mount it with ImDisk and expect the amount of RAM available to Windows to increase with the size of the virtual disk. In the first couple of cases it took me some time to figure out what they actually tried to do. But now that I get at least one such e-mail a week, often more than that, I start to wonder where this idea come from really and what to do about it.

 

Seriously now, do anyone have any idea how to avoid this kind of confusion? Should I really put a warning somewhere about that this piece of software will not increase the amount of RAM? Link to some Wikipedia page about RAM disk software? Something else?

[v77]

You sound a bit angry...

I think it's up to the users to learn the basis. Even for Imdisk Toolkit, which is designed for a larger number of people, there are a few things that I will not explain.

Even if it's not very nice, you can simply ignore the messages that bother you.
And if you want to reduce this kind of messages, you can try to add something like that on your webpage:

"This software requires that you are used with the concepts of volume, virtual memory, physical memory (RAM), and image file. Please check these links for more informations."

[Olof Lagerkvist]

Sorry, not meant to sound angry really. More kind of curious why this happens and to ask if anyone had an idea how we could avoid it. I am used to users (and myself) misunderstanding things and that by itself is not the problem, such things will always happen. I was more curious why this particular misunderstanding happens now. For many years I never got any such e-mails and now since a couple of months at least one a week. I don't answer all e-mails because I simply don't have time to answer everything, but I try to monitor what kind of questions are the most common ones and when and why most common questions change over time. I guess some expectations, understandings, etc have changed somehow for some reason and that this might mean that things need to be explained in a slightly different way than it has been before.

 

This idea with links to Wikipedia pages looks like something that could be useful. I think I'll add something like that somewhere in the user interfaces. Thanks!

 

[Wonko the Sane]

Also my guess (crystal ball a bit foggy at present ) is that some of those will attempt to use IMDISK or IMDISK tool to put on the created volume a pagefile.

A link to this:
http://www.overclock...e-on-a-ram-disk
 

Yes, putting the pagefile on a RAM disk is ridiculous.

may thus be of benefit.

Of course if a driver such as Gavotte's or DataRam's are used to make use of the RAM that is not used/addressed anyway on 32 bit systems (above 4 Gb )it may make (some) sense, but definitely it's not something that an unexperienced user should even think of attempting.

 

Wonko

[Hydranix]

Perhaps it's the holidays?

 

I imagine that each year around December, there is an influx of newly non-mobile computer users entering the digital world. Imagine coming to age and having only ever used an iPhone or Android device. Misconceptions would be plenty. Most of us probably started decades ago when things were simpler.

 

Maybe I'm wrong, but it sounds cool.

 

 

Olof, I don't think you should post a warning, and definitely not have one in ImDisk itself. Excessive warnings and safety bumpers make quality tools like ImDisk lose some of their elegance. At least in my opinion.

 

 

If the emails are starting to get a little annoying, try having a little fun with them X) Joking of course.

Edited by Hydranix, 05 January 2016 - 06:30 PM.

[xyBogli]

My confusion comes from other sources.. sources like this post on another forum.

I'd like to know if that is true, or a simple misinformed user ? I thought imdisk was caching at drive level too..

Can you guys please clarify ?

 

Thanks

 

Quote:

Originally Posted by marccoc 

I've heard good of Primo, but can you tell me why have you decided to use a proprietary software over an open source one like imdisk ?
I'm not favoriting any, just want to have some guideline in my own descision.
thanks

 

 

 

imdisk is not a RAM cache like Primo cache - it is a ramdisk. Primo caches disk blocks at the driver level.

I use primo and it is pretty good. I cache 14GB of my C drive and 2 GB of my cache drive (photoshop, browsers, etc)  - both are partitions on an 850 Pro SSD.  It will persist the cache across boots.

Post url: http://www.overclock...0#post_24782163

[Olof Lagerkvist]

@Boogyxy
 
A RAM disk driver and a cache driver (technically a filter driver) are basically different designs. A RAM disk driver creates a new disk volume with a new drive letter. Everything you save on this virtual disk volume is saved in RAM only and is never saved to a physical disk volume (unless you copy files manually or use RAM disk drivers that have specific features added to automatically copy files when system shuts down etc). To be able to use the RAM disk you need to use the drive letter for the RAM disk, it does not speed up access to other, physical disk volumes.
 
A cache filter driver on the other hand, connects to an existing physical disk volume and speeds up access to it by caching write and read operation in RAM. This means that an existing physical disk volume gets faster without any need for an additional virtual disk volume. You simply use the same drive letter and paths as you would normally do without the cache filter driver.

 

Then, to add cache features to a RAM disk, either directly or by adding another cache filter driver, would not make much sense. This is because the RAM disk already keep everything in RAM and there would be no performance gains in adding extra steps of RAM storage and book-keeping logic to it.
 

@ All

 

Thanks for all the input. I am about to put together some kind of FAQ/dictionary that explains a few things that are frequently asked. The old FAQ was once assembled from questions that were very common back then, but it has become really outdated and out of interest for most users these days I would think. I guess it's time to rename the old FAQ to "FAQ advanced operations" or something like that and then create another FAQ/terms dictionary for the most common questions/misconceptions from the last two-three years. I hope that would be more helpful than the old FAQ.

[Hydranix]

A cache filter driver on the other hand, connects to an existing physical disk volume and speeds up access to it by caching write and read operation in RAM. This means that an existing physical disk volume gets faster without any need for an additional virtual disk volume. You simply use the same drive letter and paths as you would normally do without the cache filter driver.

 

 

Not to divert from the topic, and I'm not directing these questions at you Olaf. I'm just curious why anyone would want to buy Primocache.

 

Software like that seems to be a bit of snake oil, and counterproductive as well.

 

A RAM disk has many practical uses with few drawbacks. While doing volume level caching doesn't make much sense to me.

 

A cache filter driver would be doing something which the operating system already does, but at a somewhat lower level (probably better to say a "different layer"). Wouldn't the filesystem cache be far more efficient and more capable of being optimized further than a filter driver? Admitted, I've not written a driver yet, so I don't know for sure.

 

Wouldn't a filter driver like the one Romex offers waste memory by caching blocks containing data which was already cached by the filesystem cache? Without a way to coordinate with the filesystem cache the overlap would be unavoidable.

 

Doesn't Microsoft already have this sort of functionality in Ready​Boost as well?

 

Perhaps a severely memory constrained system with an SSD and HDD could find benefit from that sort of caching, but for the $30 a license costs for Primocache, you could buy 8GB more of RAM, which would be better in every way.

[Olof Lagerkvist]

Well, such arguments are usually used against RAM disks as well. I agree that for most people things like file system cache and ReadyBoost already provides good enough cache mechanisms that make things like cache filter or RAM disk unnecessary.

 

But on the other hand there are certain scenarios where they are really useful and make a noticeable change too. I have used a similar write cache filters for instance with a USB thumb drive that were fast when reading but awfully slow when writing. An extra level of lazy-writebehind cache helped a lot. Another usage case is image files mounted across network and similar.

[Hydranix]

Well, such arguments are usually used against RAM disks as well. I agree that for most people things like file system cache and ReadyBoost already provides good enough cache mechanisms that make things like cache filter or RAM disk unnecessary.

 

But on the other hand there are certain scenarios where they are really useful and make a noticeable change too. I have used a similar write cache filters for instance with a USB thumb drive that were fast when reading but awfully slow when writing. An extra level of lazy-writebehind cache helped a lot. Another usage case is image files mounted across network and similar.

 

I definitely overlooked the remote image mounting use case. That has to be incredibly useful when almost every implementation of remote mounting falls short in caching performance, save for a few heavyweight ones like iSCSI or Fiber Channel-based image files. Thanks for pointing that one out for.me.

[xyBogli]

Thanks Olof for you reply

@Boogyxy
A RAM disk driver and a cache[...]
A cache filter driver on the other hand, connects to an existing physical disk volume and speeds up access to it by caching write and read operation in RAM. This means that an existing physical disk volume gets faster without any need for an additional virtual disk volume. You simply use the same drive letter and paths as you would normally do without the cache filter driver.

I think I my understanding comes from the fact that I forgot about HDD ..  I switched to SSD only couple years ago. But I'm still not getting how could such cache filter be beneficial to user with 2 SSD, is it ? (I would understand the SSD Caching on an HDD, but not SSD caching on SSD...)

@ All

Thanks for all the input. I am about to put together some kind of FAQ/dictionary that explains a few things that are frequently asked. The old FAQ was once assembled from questions that were very common back then, but it has become really outdated and out of interest for most users these days I would think. I guess it's time to rename the old FAQ to "FAQ advanced operations" or something like that and then create another FAQ/terms dictionary for the most common questions/misconceptions from the last two-three years. I hope that would be more helpful than the old FAQ.
I think its a real good suggestion indeed

 

Couple additional questions:

- I'm not sure if my current Imdisk config is set properly. It might be, but I'm wondering why does my 16Gb total physical RAM is never user more than 26-29% ?

 

I've created a 12Gb ImDisk RAM Drive to run Firefox on.

- I've done many browser performance stress test (while the said browser was entierely relocated on the RAM Drive), and couple other heavy task, but the total used memory won't ever raise over 26-29%

Could it be something wrong with my ImDisk Configs ?
Do I need readyBoost enabled on my system ? (it's disabled for some reason as I look now)

Could it be some Firefox's about:config mods that I would have omit  ? (I saw few good reference on relocating Full Firefox browser to a RAM Drive)

 

- Windows temp & caching: I've done the proper Environment variable change to relocate the windows cache, but when I digg and look deeper at some process over ProcessExplorer, I see many temp files still stored and read from the ssd drive. I guess there are more than only those Environment Variable to change, could it be ?

 

Here's some of my config: https://i.imgur.com/kMnqzsl.gif

(i put gif cuz mp4 affraid too many user, sorry for the no-control playback it's a gif)

[Olof Lagerkvist]

I think I my understanding comes from the fact that I forgot about HDD .. I switched to SSD only couple years ago. But I'm still not getting how could such cache filter be beneficial to user with 2 SSD, is it ? (I would understand the SSD Caching on an HDD, but not SSD caching on SSD...)

I was referring to using RAM to cache SSD and using RAM to cache HDD, not caching SSD with SSD.

[xyBogli]

I was referring to using RAM to cache SSD and using RAM to cache HDD, not caching SSD with SSD.

What happens when a transfer occur between 2 ssd, and there's no such Cache Filter (nor RAM Drive) installed on the system ?

Doesn't that transfer uses the RAM anyway inbetween ? If not, then I now understand more the purpose of Cache Filter (I haven't found any wiki on that, unfortunately, hence my "novice" questions

 

As for my previous post, I'll hope you have time to answer me later on

especially about memory usage level that seems to not goes over 29%

 

Now about Cache Filter applications, I might give a try at MaxVeloSSD and attempt to improve transfert speed between my 2 ssd ... I bet it could be beneficial with my NAT 1tb HDD too... Would that make any sence ?

(MaxVeloSSD claims to have some automatic memory selection switching. when one is full or not available anymore at some point during any specific transfert ... ie: The software first tries to use allocated system’s RAM to use as a cache, if this is not / no longer available, it will start using the SSD as cache and when that can be no longer used data will be stored on the HDD.

 

On an offtopic side note, any of you actually receive subrcibted thread's notification by email ? it doesnt seems to work for me on that forum, no mather what I try.

 

PS. I'm not english-native. So please forgive my spelling and remember that language barrier alter most ppl's perception over the non-native speaker.

Edited by Boogyxy, 12 January 2016 - 01:53 PM.

[Wonko the Sane]

Let's see if I can use one of my half-@§§ed examples.

 

Imagine you have a bottle of beer and a glass.

You pour the beer from the bottle into the glass.

 

Of course the beer cannot flow out of the bottle at a faster rate than its bottleneck allows (it is actually a bottleneck ).

 

Now imagine that (for some strange reason ) you decide to not drink the beer, so, in order to be able to store the beer, you start to pour back the beer from the glass into the bottle.

 

While in theory you could manage to re-fill the bottle at the same rate you previously emptied it into the glass in practice the filling rate of the bottle is much lower.

 

Now imagine that you have handy a (largish) funnel, you insert it into the bottle and then pour in the funnel all the contents of the glass at once.

 

The filling rate of the bottle will not anyway have exceeded the rate with which it was emptied before, but you will get the glass empty much earlier. 

 

Let's say that:

- pouring the beer from the bottle into the glass is similar to reading data from a hard disk (or SSD) and writing it to RAM (or anyway from "slower" to "faster")

- putting back the beer from the glass into the bottle is similar to write data from RAM to hard disk (or SSD) (or anyway from "faster" to "slower") and reading data from hard disk or SSD is faster than writing data

- using a funnel is similar to write data from RAM to hard disk (or SSD) through a write cache the glass is emptied before the bottle has been filled

 

Wonko

[xyBogli]

Let's see if I can use one of my half-@§§ed examples.

 

Imagine you have a bottle of beer and a glass.

You pour the beer from the bottle into the glass.

 

Of course the beer cannot flow out of the bottle at a faster rate than its bottleneck allows (it is actually a bottleneck ).

 

Now imagine that (for some strange reason ) you decide to not drink the beer, so, in order to be able to store the beer, you start to pour back the beer from the glass into the bottle.

 

While in theory you could manage to re-fill the bottle at the same rate you previously emptied it into the glass in practice the filling rate of the bottle is much lower.

 

Now imagine that you have handy a (largish) funnel, you insert it into the bottle and then pour in the funnel all the contents of the glass at once.

 

The filling rate of the bottle will not anyway have exceeded the rate with which it was emptied before, but you will get the glass empty much earlier. 

 

Let's say that:

- pouring the beer from the bottle into the glass is similar to reading data from a hard disk (or SSD) and writing it to RAM (or anyway from "slower" to "faster")

- putting back the beer from the glass into the bottle is similar to write data from RAM to hard disk (or SSD) (or anyway from "faster" to "slower") and reading data from hard disk or SSD is faster than writing data

- using a funnel is similar to write data from RAM to hard disk (or SSD) through a write cache the glass is emptied before the bottle has been filled

 

Wonko

 

That deserve some epic mention... couldnt ever figurate this any better than that ! well done

[Olof Lagerkvist]

As for my previous post, I'll hope you have time to answer me later on
especially about memory usage level that seems to not goes over 29%

Sorry, but I don't know that much about Firefox or dynamic RAM disks, so I hope someone else could help you out there.

[v77]

Couple additional questions:

- I'm not sure if my current Imdisk config is set properly. It might be, but I'm wondering why does my 16Gb total physical RAM is never user more than 26-29% ?

 

I've created a 12Gb ImDisk RAM Drive to run Firefox on.

- I've done many browser performance stress test (while the said browser was entierely relocated on the RAM Drive), and couple other heavy task, but the total used memory won't ever raise over 26-29%

Could it be something wrong with my ImDisk Configs ?
Do I need readyBoost enabled on my system ? (it's disabled for some reason as I look now)

Could it be some Firefox's about:config mods that I would have omit  ? (I saw few good reference on relocating Full Firefox browser to a RAM Drive)

 

- Windows temp & caching: I've done the proper Environment variable change to relocate the windows cache, but when I digg and look deeper at some process over ProcessExplorer, I see many temp files still stored and read from the ssd drive. I guess there are more than only those Environment Variable to change, could it be ?

 

Here's some of my config: https://i.imgur.com/kMnqzsl.gif

(i put gif cuz mp4 affraid too many user, sorry for the no-control playback it's a gif)

 

You should not use the -P switch if you are using the RamDisk Configuration Tool of ImDisk Toolkit.
RamDiskUI.exe already mounts the ramdisk at Windows startup with all the parameters used at the creation. In most cases, the -P switch is useful only if you use the imdisk driver only, not the Toolkit. Here, it can lead to some conflicts and unpredictable effects.

The dynamic ramdisks never allocate memory blocks that are filled with 0. That's why, even with the use of an image file, the memory actually used can be less that the size of the image file.

About the TEMP environment variables, you need to reboot the system if you want that all running services and applications use the new location. There can be a few exceptions for which this will not work though, some services, or if you use a limited account on a server edition of Windows.

Edited by v77, 12 January 2016 - 07:48 PM.

[xyBogli]

You should not use the -P switch if you are using the RamDisk Configuration Tool of ImDisk Toolkit.
RamDiskUI.exe already mounts the ramdisk at Windows startup with all the parameters used at the creation. In most cases, the -P switch is useful only if you use the imdisk driver only, not the Toolkit. Here, it can lead to some conflicts and unpredictable effects.

Thanks, I wasn't sure either when I've set it. Good to know.

 

The dynamic ramdisks never allocate memory blocks that are filled with 0. That's why, even with the use of an image file, the memory actually used can be less that the size of the image file.

Would I get performance increase by removing the checked "Use AWE physical memory" setting ?

Would you suggest other parameter from within the Dynamic RamDisk Parameter options ? (than those you see in my gif: https://i.imgur.com/kMnqzsl.gif )

About the TEMP environment variables, you need to reboot the system if you want that all running services and applications use the new location. There can be a few exceptions for which this will not work though, some services, or if you use a limited account on a server edition of Windows.

I've rebooted many time since. I'm a single user Admin on my Personal PC. I bet the setting is fine then. I'll search for other potential missed OS-based Cache location .. if you know any, please let me know.

 

As for my FF browser, I will definitely need to search deeper to find and set the optimal config in there.. there are so many.

[v77]

Would I get performance increase by removing the checked "Use AWE physical memory" setting ?
Would you suggest other parameter from within the Dynamic RamDisk Parameter options ? (than those you see in my gif: https://i.imgur.com/kMnqzsl.gif )

 
Using AWE is slightly slower because each memory page needs to be "mapped" in the virtual memory space of the process. There is no memory copy at this point but still a system call, no matter you use a static or a dynamic ramdisk.
 
About the options in the "Dynamic RamDisk Parameters" dialog, if you don't care about the CPU usage, you can reduce the first parameter (Size of Allocated Memory Blocks) in order to reduce the memory consumption, especially with a highly fragmented file system.
Other parameters should be reserved for specific needs.
See the tooltips for more informations (leave the mouse over an edit area).

[wendy]

The two are different:

 

virtual ram uses a file on the hard disk (say swapper.dat), to make more ram.

A ram disk uses ram to make more file system, like r:\

 

Years ago, there was a program called MagnaRam, which compressed ram into a ram store.  One trick it needed was to set PageOverCommit in System.ini [386Enh] to a larger value.  What the critics did not realise is that you *need* to do this to increase the bits that Windows 3.1 could address, because it was meant to be run in 4 MB or 8 MB.  If you had 8 MB, and have POC set to 4 you could not access more than 32 MB.  Even with the best compression.  So if it could fake 64 MB, you need to set POC to 8. 

 

You can use a ram disk to put virtual ram on it, and the other way around too. 

 

I currently use Win32 version 6.1 (ie seven 32-bit), on 8 gb of ram,  Windows can only see 3, so i can use a PAE ram drive to simulate another 5.

 

Typically, this memory is unused, but i can put file-system objects, like temp files or swapper.dat up there as well. 

[Hydranix]

virtual ram uses a file on the hard disk (say swapper.dat), to make more ram.
A ram disk uses ram to make more file system, like r:\

Virtual memory doesn't make more RAM, and even a typical user shouldn't think that. This is why threads like this are started in the first place.

Virtual memory just allows "old data" to be moved from the RAM to somewhere else (like swapfile).

Virtual memory frees up memory, it doesn't make more memory.
 

You can use a ram disk to put virtual ram on it, and the other way around too.

 

That would be very unconstructive and detrimental to performance on any modern machine. When Windows reports that your physical memory usage it say 30%, it's actually (hopefully) using all are almost all 100% of it. The 30% is reports is just the amount of memory that cannot be freed for immediate usage. The other ~70% has cached data from the disks, mappings, tables, and all sorts of other goodies to make the computer run faster. If you were to suddenly require 80% of your memory for a video file or something you've began editing, All those goodies are thrown away to make room for the editing software to store the video file data or whatever it is that needed that memory. All modern operating systems do this. Tracking and reporting all that cached stuff though would be expensive in cpu cycles and would consume a considerable amount of memory (which would defeat the purpose of it being there in the first place).
 

I currently use Win32 version 6.1 (ie seven 32-bit), on 8 gb of ram,  Windows can only see 3, so i can use a PAE ram drive to simulate another 5.

 
Why? You're using an operating system that Microsoft artificially imposes memory restrictions on. Just use 64 bit Windows.

While using workarounds for the artificial limitations can make one feel clever, ultimately it's not worth it. It's better to properly utilize the full address size of your cpu.

Also, Win32 isn't a versionm of Windows, its the name for the API for programming for Windows. You probably mean Windows NT 6.1.xxxx 32-bit, nut still doesn't really make sense to call it that.

Edited by Hydranix, 19 January 2016 - 12:36 AM.