Multiple Writers= SLOW

[eband00]

Hey guys, i recently bought two more dvd writers to help me burn a series of tutorials i made. The problem is that.. before, i took me about 6 minuts to burn a dvd. Now it takes me 40 minuts to burn each dvd when the 3 are working? I really dont understand why.

I have 1 hardriver, western digital SATA
my 3 writers are: 2LG's and 1 pioneer, all three are Sata too.

I have a quad core intel

and 2 gig of 6400 ram.

Running windows XP pro

 

[Zorg]

Check the IDE controllers in device manager to ensure that they are running in DMA mode not PIO. I know that the drives are SATA but they run in IDE mode.

 

[eband00]

Yes, they are all running in dma. I wonder why does it do that... i means, its actually faster to burn with 1 dvd-burner than 3..
and they all write very fast when only 1 is working..

 

[skittle]

what are you using to burn? is it just an ISO image?

 

[AwsmGy]

Sounds like your hard drive is a bottle neck. If you're running all three burners at the same time that info from a single hard drive is going to be read three times, then written three times. Let's say it takes 2 minutes to burn 1 copy at a time, with you running the set up you have it should take 6 minutes, while the time it takes in more than triple the time though is beyond me. It's a long shot, but check your system resources while they're all running, it may shed some light on the situation.

 

[surrealdeal]

yes, maybe it is your "hardriver"... but the burners are not really designed to DO that...

 

[skittle]

yes, maybe it is your "hardriver"... but the burners are not really designed to DO that...

Do us a favor and get out of this thread. The burner isnt the problem.

 

[eband00]

Hmm. It is weird. Im actualy not copying the same files on the different drives. They are video tutorials and they take so much space, so each chapter is on different dvds

My components are brand new, i bought em in august. Its a western digital caviar 250gb sata.

You really think it might be the hardrive not supplying the information fast enough for the burners?

What about the ram, is there any information that goes through the ram when the dvds are being burnt?

What about running 2 hard drive in RAID mode, will it help?

 

[ausch30]

You wrote that it took 6min to burn one and then after installing the other two it takes 40min each when all three are working. Does that mean it takes you 120min to complete 3 disks or was that 40min for 3? I have seen in my experience the exponential slow down of reading or writing to disks when there is a hard drive bottle neck. I was wondering if this was a one time deal or if you were planning on copying many disks over time. If you want to copy disks on a regular basis you might want to invest in a Duplicator such as this http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2000100528+1036520714&name=DVD+Duplicator. There are many different kinds, all with different prices and if it's a regular thing it might be something to consider. Are you just writing an .img or .iso? If it's something that needs to be converted to something before being burned then the software does the conversion and saves it in a temp file on the hard drive before writing it so with 3 files reading, writing and then reading to and from the same hard drive it will slow things down quite a bit.

 

[BustedSony]

Hey guys, i recently bought two more dvd writers to help me burn a series of tutorials i made. The problem is that.. before, i took me about 6 minuts to burn a dvd. Now it takes me 40 minuts to burn each dvd when the 3 are working? I really dont understand why.

I have 1 hardriver, western digital SATA
my 3 writers are: 2LG's and 1 pioneer, all three are Sata too.

There shouldn't actually be a slowdown, the hard drive (assuming Nero is being used) writes the data once into memory, then that is the cache from which the three writers take their data, so the hard drive doesn't have to "read three times." I do think that one writer may be incompatible with the others, the Pioneer is a different Oem from the LGs, so try with just the LG writers to see if they take six minutes. I also have a multiple burner config, using four Pioneer 112/212d, and they write at the full 8X used by the Taiyo-Yuden media.

Oh, important point, make sure the sata ports used for the writers are all IDE and/or Enhanced ATA. If one writer is on IDE then another is on AHCI (which doesn't support DVDroms) then indeed there can be strangeness. Even one writer on AHCI-enabled Sata can fail. Maybe one writer is not working properly so it is keeping the others waiting??

 

[eband00]

You wrote that it took 6min to burn one and then after installing the other two it takes 40min each when all three are working. Does that mean it takes you 120min to complete 3 disks or was that 40min for 3?

It takes 40 minuts for the 3.


Well, there is no iso, its actually folders on my desktop, and when i need to make a custom ordered CD, i just drag and drop in the nero burn data dvd wizard.

I will try burning with only the two lg because they are actually identical.

How can i check if the sata ports are IDE or enhanced ATA?

And for duplicators, im doing it often enough to get me one of those really. Just sometimes, there are rushes, and i keep regretting i got 2 more burners for nothing.

 

[BustedSony]

How can i check if the sata ports are IDE or enhanced ATA?

Check in the BIOS, usually under "Chipset." That may be the whole issue.

 

[skittle]

My guess would be that nero is doing something weird. what version of nero? also, open task manager while burning... whats your cpu usage at?

 

[Slobogob]

Let's see how much Data the Burners are writing:

1x ~ 1385kibibyte per second
16x ~ 22160kibibyte per second
3x 16x ~ 66480kibibyte per second

66480kibibyte * 1024 * 8 = 544604160bit per second

544604160bit / 10^6 ~ 545mbit per second

545mbit / 8 ~ 68mb per second

A drive that can sustain 68mb per second while seeking data for 3 burners is needed.


These numbers are based on the effective write speed and thus don't contain overhead (communication, buffering, error correction etc.) and compression.

Under the assumption that you have a IDE HDD running at full 100mb (purely theoretical), the DVD Burners could be saturated quite easily.

If you do burn a DVD at 16x and task your HDD with searching a file or some other work, it may not be able to feed enough data to a single Burner (unless it cached whatever you are burning into your RAM) - if it is an older HDD. Since you burn different files on each Burner the HDD is busy seeking and can't feed data with full speed. All under the assumption that you use a single HDD.
The picture changes a little by using a SATA 150mb HDD but probably not enough to supply 3 Burners.

Here´s a little chart i found on THG showing some bandwidth data.
http://www.tomshardware.com/2007/11/21/samsung_overtakes_with_a_bang/page9.html
As you can see, most drives can easily feed 68MB per second at max speed. What you need to look for is the minimum speed though. None of the drives can deliver what you need. Under perfect conditions the fastest of them might work but i really doubt that.

What you have to do now is to find where exactly the bottleneck is. It seems easy to blame a slow HDD but that may not be enough. If you connect all your burners to your mainboards PATA controler, you may be creating another bottleneck. The controller can only supply a limited set of information (the newest ATA norm makes it 133MB) which should be enough but doesn't have to be enough if it is using a different standard and is poorly implemented.

I think the fact that you burn 3 dvd with different content is creating this problem. The HDD has to seek different data for all three drives and thus can't fill it's bandwidth proberly since it's seeking all the time.


First you should test if it is really the HDD. Borrow an external drive or a large Flash memory module. Copy the files you want to burn on that medium and burn two DVDs at max speed using the HDD as a source for one burner and the other medium as a source for the second burner. If things go smoothly, a second hdd, RAID 0 or not, will do you a big favor.

If that's the case make a RAID 0. The seek times won't improve but two HDDs have an easier time filling the Burners buffers since they have a lot more bandwidth. That will increase throughput quite a bit. In addition make sure your HDD is cleaned up. Defragment it.

While the SATA bus can feed 150mb that does not mean your HDD can feed that much data. Even with a RAID 0 you might end up with your three burners running at 12x each.

 

[skittle]

Let's see how much Data the Burners are writing:

1x ~ 1385kibibyte per second
16x ~ 22160kibibyte per second
3x 16x ~ 66480kibibyte per second

66480kibibyte * 1024 * 8 = 544604160bit per second

544604160bit / 10^6 ~ 545mbit per second

545mbit / 8 ~ 68mb per second

A drive that can sustain 68mb per second while seeking data for 3 burners is needed.


These numbers are based on the effective write speed and thus don't contain overhead (communication, buffering, error correction etc.) and compression.

Under the assumption that you have a IDE HDD running at full 100mb (purely theoretical), the DVD Burners could be saturated quite easily.

If you do burn a DVD at 16x and task your HDD with searching a file or some other work, it may not be able to feed enough data to a single Burner (unless it cached whatever you are burning into your RAM) - if it is an older HDD. Since you burn different files on each Burner the HDD is busy seeking and can't feed data with full speed. All under the assumption that you use a single HDD.
The picture changes a little by using a SATA 150mb HDD but probably not enough to supply 3 Burners.

Here´s a little chart i found on THG showing some bandwidth data.
http://www.tomshardware.com/2007/11/21/samsung_overtakes_with_a_bang/page9.html
As you can see, most drives can easily feed 68MB per second at max speed. What you need to look for is the minimum speed though. None of the drives can deliver what you need. Under perfect conditions the fastest of them might work but i really doubt that.

What you have to do now is to find where exactly the bottleneck is. It seems easy to blame a slow HDD but that may not be enough. If you connect all your burners to your mainboards PATA controler, you may be creating another bottleneck. The controller can only supply a limited set of information (the newest ATA norm makes it 133MB) which should be enough but doesn't have to be enough if it is using a different standard and is poorly implemented.

I think the fact that you burn 3 dvd with different content is creating this problem. The HDD has to seek different data for all three drives and thus can't fill it's bandwidth proberly since it's seeking all the time.


First you should test if it is really the HDD. Borrow an external drive or a large Flash memory module. Copy the files you want to burn on that medium and burn two DVDs at max speed using the HDD as a source for one burner and the other medium as a source for the second burner. If things go smoothly, a second hdd, RAID 0 or not, will do you a big favor.

If that's the case make a RAID 0. The seek times won't improve but two HDDs have an easier time filling the Burners buffers since they have a lot more bandwidth. That will increase throughput quite a bit. In addition make sure your HDD is cleaned up. Defragment it.

While the SATA bus can feed 150mb that does not mean your HDD can feed that much data. Even with a RAID 0 you might end up with your three burners running at 12x each.

No offense, but you really have no idea about how dvd transfer rates work. Not to mention that the data is cached in main memory before its written to the 3 drives. If he is doing it the proper way, the bottleneck should not be with the harddrive. Your assumption that he "needs" a drive that can sustain a constant 68mb/s is so completely off that I dont even know where to begin educating you.

 

[Slobogob]

No offense, but you really have no idea about how dvd transfer rates work. Not to mention that the data is cached in main memory before its written to the 3 drives. If he is doing it the proper way, the bottleneck should not be with the harddrive. Your assumption that he "needs" a drive that can sustain a constant 68mb/s is so completely off that I dont even know where to begin educating you.

Actually this is quite offensive. You are making a claim without any supporting facts. That's what kids do.

But let's see.

Yes the data is cached to the memory but you can't cache the amount of 3 DVDs to memory and thus only a small portion is read to it. To sustain the cache the data has to be constantly refreshed and thus read from the HDD. And voilá we´re back to bandwidth. I left that part out because it doesn't really matter.

Given your childish and offending response i'm a forgiving person and all for learning new things, so please educate me.

 

[bc4]

I would guess that it is the processor that is the bottleneck!!!! Since they are 3 separate "chapters" --- I'm guessing that they all need to encode before burning. Try burning the same chapter to all 3 burners and post the results. In my experience, video encoding is the most processor intensive task out there, even though your processor is generations better than my pentium d --- post the results.

edit: I was trying to do a somewhat similar thing. I was trying to burn a the same 30 minute video but add a unique 2 minute clip to each DVD --- to 2 burners. After about 2 months of searching, I gave up and realized that the whole 35 minutes needed to be encoded each time and it took about 45 minutes per title--- or unbelievably slow if I tried them both at the same time.

so instead of encoding with 4 cores, you are basically encoding with 4 cores/ three disks. Like 4/3 of a core 2 ---

 

[Slobogob]

I would guess that it is the processor that is the bottleneck!!!! Since they are 3 separate "chapters" --- I'm guessing that they all need to encode before burning. Try burning the same chapter to all 3 burners and post the results. In my experience, video encoding is the most processor intensive task out there, even though your processor is generations better than my pentium d --- post the results.

That's what i thought at first too, but he said he's using the Nero Data Wizard which should just add the files to the DVD without actually encoding them.
I`m not certain that even if he had to encode the videos, wouldn't nero encode them first and burn them afterwards?

 

[BustedSony]

Actually this is quite offensive. You are making a claim without any supporting facts. That's what kids do.

But let's see.

Yes the data is cached to the memory but you can't cache the amount of 3 DVDs to memory and thus only a small portion is read to it. To sustain the cache the data has to be constantly refreshed and thus read from the HDD. And voilá we´re back to bandwidth. I left that part out because it doesn't really matter.

Given your childish and offending response i'm a forgiving person and all for learning new things, so please educate me.

Apart from anything else, I have four burners, with Nero on a Q6600, and four discs on four burners ARE burned in about the same time as would be one disc. And that is without the hard drive thrashing about and without some extraordinary CPU usage.

Again, the data is cached in memory, and the burners are running at the same rate accessing the same data from cache at about the same time, and memory is way way faster than any bunch of burners could ever be. The burns are regulated to be done at the same speed, that of the slowest burner, they are reading the same part of the source image at about the same time. It is ONE DVD being cached to memory! Why the Hell would THREE DVDs be needed to be cached to memory when all the burners are making the SAME DVD?! As far as I can tell it's just one process thread, even.

The comparison with rendering mpegs is not valid, in that case each renderer is working with separate, different, data, - separate streams and process threads.

I just noticed that Nero Disc Wizard is being used with the files being dragged and dropped. That could be the slowdown, since in this case Nero has to create the disc image on the fly as it burns, and it probably has to do that for each burn. Obviously the source image should be created first, such as by making a proper data ISO, (Nero img) or copying the data to a virtual image, THEN burning that Image.

 

[Slobogob]

Apart from anything else, I have four burners, with Nero on a Q6600, and four discs on four burners ARE burned in about the same time as would be one disc. And that is without the hard drive thrashing about and without some extraordinary CPU usage.

Again, the data is cached in memory, and the burners are running at the same rate accessing the same data from cache at about the same time, and memory is way way faster than any bunch of burners could ever be. The burns are regulated to be done at the same speed, that of the slowest burner, they are reading the same part of the source image at about the same time. It is ONE DVD being cached to memory! Why the Hell would THREE DVDs be needed to be cached to memory when all the burners are making the SAME DVD?! As far as I can tell it's just one process thread, even.

The comparison with rendering mpegs is not valid, in that case each renderer is working with separate, different, data, - separate streams and process threads.

And i do believe you. But as you said you are burning the same DVD on all drives. Try burning different DVDs on all drives and see what happens. That is what the OP does and that is what is causing the problem.

 

[bc4]

yep, I didn't read carefully enough. Just saw that they were movie files and thought they needed encoding.

I'd still suggest trying one image to all three drives though --- could help us troubleshooting

 

[BustedSony]

And i do believe you. But as you said you are burning the same DVD on all drives. Try burning different DVDs on all drives and see what happens. That is what the OP does and that is what is causing the problem.

Yes, he said that in his third and fourth post, which I didn't notice. I thought he was making multiple copies for distribution. Obviously he is therefore working from scratch three times over, and burning directly from a folder takes much more resources than just burning from a formatted ISO. In other words he's dragging and dropping then burning, and meanwhile moving on to the next set of files, each having to have ISOs created on the fly. Of COURSE that's slow!! I didn't see that, sorry.

 

[Slobogob]

yep, I didn't read carefully enough. Just saw that they were movie files and thought they needed encoding.

I'd still suggest trying one image to all three drives though --- could help us troubleshooting

I agree that there needs to be more testing to determine the exact problem.

Yes, he said that in his third and fourth post, which I didn't notice. I thought he was making multiple copies for distribution. Obviously he is therefore working from scratch three times over, and burning directly from a folder takes much more resources than just burning from a formatted ISO. In other words he's dragging and dropping then burning, and meanwhile moving on to the next set of files, each having to have ISOs created on the fly. Of COURSE that's slow!! I didn't see that, sorry.

Don't worry, most of the times i don't bother reading through all of the posts either if i think i have a simple solution to the problem at hand.
There are more possible problems than just the bandwidth or the processor. It could be a glitch in the burning software or his SATA controler using a bad driver. Maybe its something totally off the map so every idea helps.

 

[RetiredChief]

No Answer, But out of curiiosity I tried burning 2 DVD+Rs.

initially, concurred with Slobogob and that still may be part of the problem.

Does not seeam to be CPU bottleneck nor limited by 2 Gigs of ram, as My CPU usage is less than 10% and avaliable ram is 1.2 Gigs.
Test:
Configuration: Plextor 755 and Samsung 183L. Both sata drives on jmicron controller.

2 WD SataII Raid 0 drives Plus 2 Segate SataII Raid 0 drives on Intel controller.

Disk -> Phillips +16 DVD+R
Files -> 4.35 gig Dvd movie Copied via Dvd shrink. Placed folder on both pairs of HDDs.

Result Very slow burn ie About an hour vs doing one in about 8 min. (only 55% complete after 30 mins)

 

[BustedSony]

I agree that there needs to be more testing to determine the exact problem.



Don't worry, most of the times i don't bother reading through all of the posts either if i think i have a simple solution to the problem at hand.
There are more possible problems than just the bandwidth or the processor. It could be a glitch in the burning software or his SATA controler using a bad driver. Maybe its something totally off the map so every idea helps.

One other thing, the files are on drive :X, the temporary image is on drive :X, probably; reading and writing to the same drive is slower than copying to a different drive, so the OP is doing this three times over.. THAT is the slowdown, having multiple read/write streams on the same drive. Ever tried running two instances of file copying from one real or virtual drive to another? One set may copy in two minutes, but two sets can take 30 minutes..