Why use kprobe?

now that i got your attention this post really should be called why do BLER scans?

ok burned about half a dvd of a tv episode backup. so I wanted to do a test to show others how you can think you have a good burn when really its not.

first i scan the dvd using cdspeed and the traditional transfer rate scan.
looks good nice burn… :wink:

most of you would probably stop now and say its a good disk im fine.
ok so maybe im a bit suspicious on this media so i run a surface test to make sure no errors occur on the read.

looks good no errors must be a good disk right.

this is where BLER testing comes into play (other uses are mentioned too, such as testing write speeds and strategies, and compatabilities with media and burners).

so im still suspicious becuase this is a crappy CMC 1x rated media burned at 2x…some of the worse crap i have…but hey no errors right??

BLER scan using kprobe2…note the high PIs. (less than 280 is the standard) as you can see the liteon accounts for the PI errors well having no real high POs (or really PIFs) but other dvdreaders (especially older home players) may not handle the high pis so well.

sure enough this disk skips in my older sony home player. also high error rates like those are sure to increase over time, soon im sure this disk will be unreadable.


Jamos, really really thanks a lot. It explain very clear and help much for any newbie like me. Also I know I choose a right drive(832S). :slight_smile:

thanx for this info.

A question for Jamos,
So can I understand from this procedure of yours, that I need to check the Kprobe first, and even if CDSpeed and the Scandisk gave not too good results, but the Kprobe gave a good result, will that mean that the Burn was Ok.

A rather complex question,
I did a few burns using Datasafe Riteks G04 with my NEC 2500a with herrie b5 firmware, stock firmware, and herrie’s b4.
I don’t have a Lite-On Burner buy I do have a reader, so I do the Kprobe tests using the Reader (SOHD-167T), i know that the results from a reader is not reliable but that’s all i can do, but the results are always fine expect for a single peak in the middle, but the average for PI is no more than 8, and the average for the PO is never more than 1.
But CDSpeed gives me a rather BAD scans, although the scandisk says that everything is fine, and I’ve tried copying the files to my hardisk, and it went fine.

Does this mean that I have bad/good/medium burns…??
Thanks for you patience, and thanks a lot for this insightful information.

Does not K-Probe scans show how Lite-On DVD drives cope with reading media? I really wish we could isolate down just how good a burn something is between Lite-On burns, Plextor burns, NEC (no real test at all except CDSpeed/DVDSpeed which seems to show things fine when other’s show loads of corectable errors), and other makes.

I have an NEC 1300 drive using 1.0a firmware (or 1.0 - release, whatever) and a Plextor CDR burner. Therefore all I can do is a CDSpeed/DVDSpeed scandisk. Wish I could see just how well (error wise) burns onto Ritek/Taiyo Yuden +R dvdr media really was in the NEC compared to a Lite-On read - which I do not own anyway :frowning:

complain to nec they do not put a diagnostic mode in thier dvd writers. but the nec generally burns better than liteons. youll just have to rely on your cdspeed scans.

and no liteons will check how good a burn is from any burner…you just need a liteon to read the disk…it doesnt have to be burned from the liteon.

you generally can ignore the high peaks and if all you have is a dvd rom then thats the best you can do. and what do you mean by cdspeed giving bad results? you mean the speed failed at a certain rate? if its just data then your dvd reader will slow down to get the data. for a movie backup you may have other issues.

and my example showed cdspeed and the surface scan giving good results and kprobe giving not so good results. first i would start with the speed scan if its ok (straight lines and no physical errors) then i would go to the next test…else stop theres no sense in continuing as you have a bad disk. the surface scan for me is optional, generally i dont do one unless i have problems playing back a dvd. then I always run kprobe2 (or cdspeed3 quality scan).


I only have a Liteon 166S DVD-ROM drive, no Liteon DVD-recorder. I downloaded kprobe and cdbremse. But to which speed do I have to set the drive to get the most accurate results? I suppose a low speed would be best. Maybe 4x or 6x? Also, cdbremse gives me the option to select, for example, between 4x and 4x-CAV. Should I use the CAV-mode or the other one?
I know that kprobe is designed for DVD-recorders and that the use of DVD-ROM drives is not recommended, but I think a scan with a DVD-ROM drive is still better than nothing :slight_smile:


Dear Jamos,

Sorry for bothering you, but probably it won’t take much of your time :slight_smile:
Also sorry for my English, it’s my second Language.

Here is a detailed series of scans
of my average burns, would you please tell me was those burns ok, would these disks live for a while, or should I be willing to replace them in a 1 year or something, what am I to worry about, what can I do to enhance them, unfortunely i can’t change the media type now, DVD Media are still rare down here.

NEC-2500A with herries b5 firmware.
RecordNow MAX 4.5 (btw, how can i make RecordNow show the actually time of the burn rather than holding a stopwatch)

The Blanks are Datasafe Ritek G04 burned at 4X bought from SVP In the UK.
The DATA burned are 700 MB files, and i’m not going to burn anything to play in a standalone device (PS2/XBOX/DVD Player) in the near future.
The Media Information is as follows :

   Media Information                            
Region information                                    N/A not a DVD-VIDEO
Media code/Manufacturer ID                                       RITEKG04
Format Capacity                                             Not Formatted
Free Blocks                                                     412352512
Free Capacity                                              4.38GB(4.71GB)
Book Type                                                           DVD-R
Media Type                                                          DVD-R
Media Id Code Speed                                       4.0x   5540KBps
Available Write Descriptor                           CLV  8.0x  11080KBps
Available Write Descriptor                           CLV  5.9x   8112KBps
Available Write Descriptor                           CLV  4.0x   5540KBps
Available Write Descriptor                           CLV  2.0x   2770KBps
Write Strategy Speed                                        4.0x 5540KBps
2x Speed OPC beta                                                      08
2x Speed OPC power                                                     12
2x Write Strategy field 1                                     11 86 67 80
2x Write Strategy field 2                               88 80 00 00 00 00
4x Speed OPC beta                                                      05
4x Speed OPC power                                                     1B
4x Write Strategy field 1                                     0E 10 08 09
4x Write Strategy field 2                                     97 06 0D 0B
4x Write Strategy field 3                                     00 00 00 00
4x Speed OPC beta multi-pulse                                          04
4x Speed OPC power multi-pulse                                         1D
4x Write Strategy field 4                                     18 A8 88 85
4x Write Strategy field 5                               89 AC 88 80 00 00
4x Write Strategy field 6                                  00 00 D0 00 00
Data area starting sector                                          30000h
Linear Density                                                0.267um/bit
Track Density                                                0.74um/track
Number of Layers                                                        1

Kprobe 1 : is the Kprobe v2.1.0 scan using My LITE-ON DVD SOHD-167T Reader.

Kprobe 2 : is the same scan removing 3 high peaks from the PI Chart, and another three from The PO chart.

SurfaceScan : is the surface scan using DvdInfoPro.

CDSpeed : is the CDSpeed v3.0 Test, sometime there are those small ups and downs in the middle of the curve too.

This DVD was copied to hardisk Using the Lite-On Reader with the patched 16X f/m In Exactly : 5 minutes 39 seconds

Thanks a lot for you time and information.

looks good to me…everything looks fine. your drop off in speed may be a issue at the end of your burn not sure why its doing that but for readability your dvd will just slow down to read the disk (ie it did not abort). small dips in the read graph are normal…yours really slows down at around 8x…should be ok though. Herries next fw should make the ritek r04s better :wink:

I thought there was a speed patch out thier that fix the diagnostic mode on that drive to be more accurate. may want to do a search. and 4x even if CAV is best :wink:

Thank You VERY MUCH for your reply.

One last question though, If Kprobe scan was fine and the CDSpeed test was not, or vice versa, what would that mean…?
Kprobe scan Good, CDSpeed test Bad = ?
Kprobe scan Bad, CDSpeed test Good = ?
What does the Kprobe scan reprsent, i know PI and PO errors, but does indicate life expectancy of the disc, readablity, same question for CDSpeed Test, does it indicate how good your Disc will be when read at a standalone device.

Much thanks, and sorry again for bothering, hope your patience isn’t running out. :slight_smile:

if cdspeed is real bad (fails to finish or the transfer rate starts to go down at a relavitly low scan speed) then you probably dont have a great burn even with a good kprobe result. but if kprobe has really high errors and you get a good cdspeed error then you have a bad burn most likely as shown by my example above…though it may play ok in some burners that can handle errors well…the longectivity of the disk would be questionable as error rates will increase over time.

Jamos: I am sure I am missing something simple but do you have any suggestion as to why Kprobe2 will not recognize my Liteon 167T? CDSpeed and everything else work fine but not Kprobe. The only thing I can think of is that it is set as slave.


try using spti driver.

Much thanks, that was it.

I have a question for you. In general terms, which would you prefer: First choice is DVD-R media that will give low PI numbers at 4X (25 or so) and PIF of less than 1 but when it is measured at 12X the PI rises to 240 and the PIF goes to 11. The second choice gives numbers of 160 PI and less than 1 PIF at 4X and when measured at 12X it goes up to 180 PI and under 2 for PIF. As expected, when the first one is measured at 12X under the CDSpeed transfer rate there are many drops in the graph as soon as it passes 8X while the second media is a straight line all the way through 12X.

This is a real question as I am seeing both these results with my two media. All scans are with the Liteon 167T.

Many thanks for your experience.

errors shouldnt rise much when you increase speed thats usually a sign of bad media or a not so good burn…you should see slight increases.

So you would say that the CDSpeed tests at 14X are a valid indicator of a problem even though the Kprobe shows the media as very good? It is Ritek G04

Thanks again.