Buffer & write speed drops at certain %



Recently I’ve been doing a considerable amount of burning (movie & PS2 DVD game)using ImgBurn (new user here). I haven’t paid attention to every burn I ran (instead I’m watching TV/playing), but on two burn processes I monitored, something happened.

At certain percentage, the buffer (not device buffer) suddenly dropped very low, thus the writing speed also dropped, while (if I remember correctly) the device buffer stayed the same (around 100%, more or less).

After a few moment, the buffer started increasing again, and so does the writing speed.

At the end of burning process, ImgBurn reported (as usual) ‘successfully!’. I’m not using ‘verify’ though, but I usually test the media directly to PS2 console or DVD player (they booted fine).

  1. Now, does it mean that the DVD was badly burned, thus the quality drop significantly, because of the sudden buffer drop?

  2. If it doesn’t (number one), then I still have a good quality backup?

  3. any ideas why the buffer sometimes drop (I notice it twice already)? What’s the remedy?

Windows XP SP3
C2D E6750
2GB Team Dark PC 6400
200GB WD Caviar HDD
burner: Pioneer A12FX with 1.24 firmware
media: Verbatim DVD-R 8x and BenQ (Daxon) DVD-R 16x

Anyway, just now I’ve run a verify on a DVD I suspected being the victim, but it’s read with my other drive, Teac DV-W516E.


imgburn saves a graph for every burn. since you already have dvdinfo pro and know how to post a screen shot. please post the imgburn, dvdinfo pro burn graph.

by default the graph data is saved C:\Documents and Settings[I]User[/I]\Application Data\ImgBurn\Graph Data Files\

many drives perform what can be called Walking Optimal Power Calibration or Online Hyper Tuning or some other fancy name. basically the dvd drive will recalibrate the laser power during the burn to optimize the burn quality. or the drive may drop the speed if a simple recalibration is not sufficient. during recalibration the burn speed and buffer drop briefly.

the fist image is a burn from a Pioneer 115D which recalibrates the laser many times during the burn process.

the second image is from a Optiarc 7201A which dropped the speed from 10x to 8x.


here’s the image. I remembered burning it at night :slight_smile:


looks good to me. :slight_smile:

your CPU looks good, write speed looks good, the single large 45% buffer dip could be system related. [maybe something in running in the background or multitasking] do you have other write graphs to compare? do you have write graphs at more than 6x?

do you have a LiteOn , BenQ or newer Samsung dvd drive which is capable of dvd Quality scanning using cd-dvd speed?


Well, I usually do nothing when burning, and I only have Avast!, Zone Alarm, nVidia icon, and Realtek HD Audio Manager running in the background.

FYI, I just recently switched to ImgBurn. I usually use Nero 6 (for years) to burn media (mostly at 4x speed) either CD or DVD, and I have no problem.

I haven’t done burning at the speed exceeding 6x with ImgBurn. However, I attached some image taken during another session of burning:


those graphs look normal. :iagree: i would not worry about it. :disagree:

ImgBurn reports real time burn speed and buffer levels, where ner0 does not. so its just a new experience. your drive will react the same which ever program you are using. :slight_smile:

you can test this with ner0 cd-dvd speed using Create Disc. then post the resulting graph.


so, (to assure myself) that buffer dip and write speed drop that occured in my #3 post is perfectly normal, meaning there’s no problem with the burned result? (So I wouldn’t have to make another backup :)) ?


Also, I’ve been thinking, does increasing the buffer size from 40mb to 128mb will help eliminating the buffer and write speed dip in the future?


[QUOTE=keigo_kanzaki;2179451] there’s no problem with the burned result? (So I wouldn’t have to make another backup :)) ?[/QUOTE]

there is no 100% way for me to know this. if you are worried just make another one.

if you have the right types of drives you can test the disc, but this will take more time than if you were to just make another one anyways. pioneer drives are good for doing Transfer Rate Tests. this test will check if the data on the disc is actually readable. large dips in the TRT graph means the drive has to slow down to read a potentially bad area, whether from a defective disc or poor burn quality.


[QUOTE=keigo_kanzaki;2179468]Also, I’ve been thinking, does increasing the buffer size from 40mb to 128mb will help eliminating the buffer and write speed dip in the future?[/QUOTE]

increasing the write buffer will help if your system does not supply data to the drive as fast as the burn rate.

your drive will fill a small buffer of 2 MB then ImgBurn will fill a 40 mb buffer. if your hard disc is too busy to supply the data, the buffers will start to deplete. since your buffer did not reach 0% i do not think this was the cause of your drop in burn speed. but having a larger buffer could not hurt. unless you are low on Random Access Memory.


I’ve run a TRT test on the disc mentioned earlier (burning it at night):

<a href=“http://s34.photobucket.com/albums/d115/keigo_kanzaki/?action=view&current=PIONEER_DVD-RW__DVR-112_124_19-D-1.png” target="_blank"><img src=“http://i34.photobucket.com/albums/d115/keigo_kanzaki/PIONEER_DVD-RW__DVR-112_124_19-D-1.png” border=“0” alt=“Photobucket”></a>

I also ran burst test:

<a href=“http://s34.photobucket.com/albums/d115/keigo_kanzaki/?action=view&current=PIONEER_DVD-RW__DVR-112_124_19-Dece.png” target="_blank"><img src=“http://i34.photobucket.com/albums/d115/keigo_kanzaki/PIONEER_DVD-RW__DVR-112_124_19-Dece.png” border=“0” alt=“Photobucket”></a>

And lastly, I’ve burned another ISO project (FF7AC this time) on a Daxon016S, burned @6x with Pioneer A12FX. This time the buffer size was increased to 80MB (matched Nero 7 :)) Somewhere along the process, I noticed the writing speed slowed down a bit, and then speed up again, while the buffer level stayed the same (100%), device buffer fluctuated around 100%-94%:

<a href=“http://s34.photobucket.com/albums/d115/keigo_kanzaki/?action=view&current=ff7ac.png” target="_blank"><img src=“http://i34.photobucket.com/albums/d115/keigo_kanzaki/ff7ac.png” border=“0” alt=“Photobucket”></a>

Anyway, thanks for your help and patience, troy512 :slight_smile:




Also, I’m stufying ImgBurn and found this OPC feature disabled (by default). My Pioneer drive also has this feature http://www.pioneer-dvdasia.com/Products_Detail.asp?sn=113&class1=DVD%20RW&ck=DVD%20RW, however, I don’t know if Pioneer enabled/disabled this by default (where can I find the info?)

If I enable OPC in ImgBurn, will the drive burn at stable speed instead of varying (since it has performed calibration before burning)?


i still believe it all looks good. :iagree:

Performing Optimum Power Calibration (OPC ) is a special technique used in newer CD/DVD recordable drives to perform a test write and read in an area inside of the lead-in, in order to determine the best laser power for recording and to adjust to each recordable disc, which may vary slightly from different manufacturers, or for other reasons.

If I enable OPC in ImgBurn, will the drive burn at stable speed instead of varying (since it has performed calibration before burning)?

there is no method to disable Active OPC with a Pioneer drive. besides this is a good thing. especially if using Daxon media. :slight_smile:


all right, thanks for all your help, troy! I really appreciate it :slight_smile: