Burn from multiple (different) burners using a RAMDisk

eric93se 2011-11-01 14:45:20 UTC #1

I did some searching in the forums to see if anyone is using this burning technique and turned up empty. So here it goes, you've got several burners of different makes and want to burn a bunch of discs with the same exact content. I have not tested this with a fast SSD drive so it will be interesting to see if someone wants to try and duplicate these results. Basically you need a PC with at least 8GB RAM (to handle a DVD image) less if you want to burn CD's. RAMDisk software, I'm using GiliSoft RAMDisk, sells for $25, simple interface and works well. My PC tower can hold 3 burners, they are Pioneer 215L, Samsung 203N, and just recently acquired a Lite-On IHAS124 cross flashed to a 624. Open IMGburn and turn off all logging options, I also reduced the Buffer Size ( I/O ) tab down to 11MB. I didn't do a lot of testing with the Buffer Size to see if there was a performance effect but everything ran well. Turning off logging reduces any unnecessary HDD writes potentially hurting performance.

So basically you start your RAMDisk, a size of 4800MB is plenty big for a SL DVD, copy and paste your DVD data over to the RAMDisk. Load your burners with blanks. Open three (or however many burners your using) instances of IMGburn, set your desired burn speeds and such. My old burners do well at 12X and complete close to 6 minutes, the new IHAS624 takes 7 minutes at 12x so I'm using 16x and now all three burners complete at the same time (within a couple seconds). After the RAMDisk is finished copying files onto it your ready to select the data you want to burn from the RAMDisks in IMGburn. Go ahead and start each instance of IMGburn and watch the buffers stay rock solid at 100%.

Most of us don't need a DVD duplicator for those rare times we need to burn multiple discs nor do we want to invest in a device that is inferior to our modern PC's. Also note it should be possible to install IMGburn on the RAMDisk, this may reduce HDD access even more while burning, the RAMDisk software then has the option to save whatever data is on your RAMDisk for future use in a image file.

I'm a little disappointed with the LiteOn performance but hopefully its learning

DrageMester 2011-11-01 15:10:31 UTC #2

Interesting. Did you try and see if the normal file-caching in Windows is good enough to handle the same triple burning job on that same machine with 8 gigs of RAM?

eric93se 2011-11-01 16:40:40 UTC #3

[QUOTE=DrageMester;2609957]Interesting. Did you try and see if the normal file-caching in Windows is good enough to handle the same triple burning job on that same machine with 8 gigs of RAM?[/QUOTE]

Well always in the past (XP) we weren’t able to burn to two drives at the same time due to the slowness of a HDD. For a HDD to read at 20MB/s three different sources (three different drives) and then the software has to create a read buffer as well (on the HDD), it wouldn’t be possible, the writing speed would drop dramatically. Does WIN7 have anything in it special to do this, I don’t know but doubt it. Maybe a Z68 MB with a caching drive.

DrageMester 2011-11-02 02:41:10 UTC #4

[QUOTE=eric93se;2609969]Does WIN7 have anything in it special to do this, I don’t know but doubt it. Maybe a Z68 MB with a caching drive.[/QUOTE] The most important thing Windows 7 64-bit has is, that it can actually use more than 4 GB RAM and will happily use almost all “free” memory to cache files (well, pages actually).

So if ImgBurn or another burning program reads the files or ISO image in a way that uses the page cache, then a system with enough RAM could in theory burn the same files multiple times after only reading the files once into the page cache. ImgBurn may read into its buffers bypassing the normal page cache, however - I’m not sure.

Since theory and practice are two different things, I was interested to know if you had tried this burning attempt without going to the trouble of manually caching stuff into a RAM drive, but I guess you haven’t.

EDIT: After looking at the ImgBurn options, I’m guessing that “Reading - Always Use Buffered I/O” controls whether the page cache (buffered I/O) is used, and this is disabled by default.

eric93se 2011-11-02 09:59:24 UTC #5

To my total surprise, it does work. I selected to ‘always use read buffers’, then tried two burners and it was successful with only some minor buffer hick-ups, they verified fine. Then tried three burners and it went just as well. This is using a very slow HDD as well. I remember in the past this couldn’t be done, so is this due to more RAM in todays PC’s? Improvements in IMGburn? higher bandwidth capabilities of memory controllers? Windows 7 shaking the cobwebs out?

Well one advantage of the RAMDisk is that there are no moving parts to wear out like in a HDD.

DrageMester 2011-11-02 13:09:51 UTC #6

[QUOTE=eric93se;2610065]so is this due to more RAM in todays PC’s? Improvements in IMGburn? higher bandwidth capabilities of memory controllers? Windows 7 shaking the cobwebs out?[/QUOTE] The essential difference is, that Windows 7 64-bit with 8 gigs of RAM is able to buffer the entire set of files (or ISO image) in memory. If it were only able to buffer part of the file set (or ISO image), then the performance would be entirely dependent on the harddisk (or SSD) performance like with Windows XP 32-bit with 4 GB RAM or less.

In theory, if the simultaneous burns are fairly well synchronized (as to when they need which pages of which files), a page cache significantly smaller than the full file set may even be good enough for uninterrupted simultaneous burns of the same file set (or ISO image), when buffered I/O i.e. the page cache is used by the burning programs… in THEORY!

eric93se 2011-11-02 14:02:35 UTC #7

Well I know one thing for sure, IMGburn does not write all the data to RAM, at least not at once, it will write to it as it needs it.

Burning simultaneously with three different burners and three separate instances of IMGburn will need all the data to be written three separate times. If the burners were identical all the writing strategies would be the same as well as the optimizing techniques that the drive uses would be in sync. And having three separate instances of IMGburn I’m sure there not talking together.

I’m amazed that it worked because the current OS HDD I’m using is so slow, If I remember its like 60MB/s peak.