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PostPosted: Tue Jul 08, 2003 6:47 pm
by cfitz
aviationwiz wrote:There is no speed throughout the burn, as it keeps adjusting.

I realize that in general the speed is not constant throughout the burn (unless the drive is using CLV mode), but when the speed drops, does it remain constant after that (and thus would be the speed at the end of the burn as I mentioned earlier) or does it start rising again until it encounters more problems, then drops again (producing a saw-tooth pattern of writing speed)?

aviationwiz wrote:Sorry, I forgot to mention what the power adjustment was at, it was at 0.

In most of your other tests you used Taiyo Yuden media. Did you also use it for the VariRec test?

cfitz

PostPosted: Tue Jul 08, 2003 6:58 pm
by aviationwiz
Yeah, sorry I misunderstood. Once the speed drops, it stays thier for the rest of the burn.

I did use the Fuji TY 48x disks for the VariRec Tests.

PostPosted: Tue Jul 08, 2003 10:48 pm
by cfitz
aviationwiz wrote:Once the speed drops, it stays thier for the rest of the burn.

Okay. I follow you now.

aviationwiz wrote:I did use the Fuji TY 48x disks for the VariRec Tests.

In that case, the settings you used on your VariRec test are the default settings for that media, so enabling or disabling VariRec should have no effect on the burn at all. Neglecting any random variations in burning and testing, the differences that you attribute to VariRec are not due to VariRec but rather solely the result of the different burn speeds you used.

It would be more interesting to burn, for example, five discs all with VariRec enabled, using the same dye setting but adjusting the power slider to -4, -2, 0, +2 and +4. Of course you could also use more discs and adjust the power slider in finer increments. Then if you wanted you could also burn one disc at the same speed as VariRec uses but with VariRec disabled. That disc should test the same (within measurement error) as the disc burned at VariRec with the power slider set to 0.

cfitz

PostPosted: Wed Jul 09, 2003 12:37 am
by dolphinius_rex
Aviationwiz: Try burning something using Alcohol 120% and take a screen shot of the performance graph, as it shows the burn speed over the whole burn process. It could be very informative for understanding PowerRecord!

PostPosted: Wed Jul 09, 2003 12:58 am
by CDRecorder
Thanks for the comparison between the LTR-48125W and the Plextor Premium. It's interesting that the LTR-48125W reports less errors.

PostPosted: Wed Jul 09, 2003 1:11 am
by KCK
aviationwiz:

Thanks for the timining results. Apparently KProbe was reading at 16x, since 74min/16x = 4:37, which is close to your 4:36.

According to your timing and my calculations, Q-Check at 10-24X CAV should reach the reading speed of 24x at MSF = 60 min. Well, my calculations are based on a simplified model (which assumes that the speed grows linearly from the initial 10x to 24x at MSF = 60 min), and they could be wrong, but MSF = 60 min looks a bit small here.

To check such calculations, I would need more data. Could you give more timings for discs which hold almost 80 min of data?

PostPosted: Wed Jul 09, 2003 1:27 am
by aviationwiz
dolphinius,

I'm going to give this Alcohol 120% a shot pretty soon. Right now I'm just burning a disk that is as close to 80 min. as I could get.

PostPosted: Wed Jul 09, 2003 1:38 am
by aviationwiz
It took the Premium 4 minutes and 30 seconds to read a disk that has an MSF of 79:47:00

This must have been a bad burn. It is the first C2 Error I have ever encountered with this drive.

Image

PostPosted: Wed Jul 09, 2003 1:47 am
by cfitz
KCK wrote:According to your timing and my calculations, Q-Check at 10-24X CAV should reach the reading speed of 24x at MSF = 60 min. Well, my calculations are based on a simplified model (which assumes that the speed grows linearly from the initial 10x to 24x at MSF = 60 min

KCK, why are you assuming 24x CAV reaches 24x at 60 minutes? It should reach 24x at 74 minutes for a 74-minute disc or 80 minutes for an 80-minute disc, either figure regardless of how much data is actually written on the disc. Naturally, if a disc is written to less than its full capacity, the top speed will not be reached.

cfitz

PostPosted: Wed Jul 09, 2003 1:53 am
by aviationwiz
Here's the Alcohol 120% Graph:


Image

PostPosted: Wed Jul 09, 2003 2:00 am
by aviationwiz
Intresting, that disk with all the C2 Errors checked out perfect in Nero CD Speed's CD Quality Check and on ScanDisc Surface Scan.

PostPosted: Wed Jul 09, 2003 2:31 am
by aviationwiz
I tested the disk with the C2 Errors on my LTR-48125W. Intresting that the Lite-On did not find it as a C2 Error but just a high amount of C1 Errors.

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PostPosted: Wed Jul 09, 2003 3:29 am
by dolphinius_rex
Interesting Alcohol 120% results! thank you very much!

So when the burn speed is modified by power record, it does continue to climb, and can be modified again as needed. I've seen my LiteON perform this way as well on occasion, although I normally choose my writing speeds very meticously.

Regarding the C2 spike reported as a C1 spike, I think the LiteON drive is a little less sensitive to the differences between C1 and C2 then the Premium.

PostPosted: Wed Jul 09, 2003 2:34 pm
by MediumRare
Aviationwiz, you came very close to doing the test I wanted for a comparison with AudioDev with your "24x" scans. Would you be willing to scan that disk again at 8x? (set 10x on the LiteOn with KProbe V1.1.14).

A couple of tips on KProbe- deactivate the "Realtime chart" for more accurate scanning results and save the image as a PNG via the save button- it's easier than going via capture program. You can combine the charts to save space if there are no C2 errors (use the setup button).

G

PostPosted: Wed Jul 09, 2003 3:33 pm
by aviationwiz
If you mean scanning the disk with all the C2 Errors, I already threw it in the garbage, sorry. If you mean the original test disk, I'm going to go do that now.

PostPosted: Wed Jul 09, 2003 4:22 pm
by MediumRare
I mean this one, but at 8x:
aviationwiz wrote:This is the Fuji 48x TY disk from my Review. The disk was burned on the Premium with firmware 1.0 and it is being tested on the Plextor Premium with firmware 1.02 and the LTR-48125W with firmware VS0D. Testing is being done at 24x.

Thanks.

G

PostPosted: Wed Jul 09, 2003 5:11 pm
by aviationwiz
Here you go:

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PostPosted: Wed Jul 09, 2003 5:32 pm
by MediumRare
Now that's very interesting- considering the coarse scale on the Plex plot (1 unit = 8 counts) these scans are extremely similar. The clusters at 25 and 29 min. line up very nicely- both location and magnitude! So do the isolated peaks at earlier and later times.

I think that this goes a long way to showing that these consumer drives are showing the same information, +-20%. At low scan spped, this should be primarily the media and not so much the drive reading capabilities showing here.

Now let's see if Halc can do some similar scans with his drives at 8x. Perhaps the factor 3 he's seeing is a result of scanning at 24x (CAV).

G

PostPosted: Wed Jul 09, 2003 6:20 pm
by dolphinius_rex
Aviationwiz: The version of K-Probe you're using has a bug that causes the reading speed set to not be the actual speed tested at. SO your test at 8x is actually at 4x... try downloading the new version 1.1.16 from the K-Probe thread, it appears to work better so far.

PostPosted: Wed Jul 09, 2003 10:14 pm
by aviationwiz
Look at the graph again. Speed: 10

I did the test at 10x so it would actually test at 8x.

PostPosted: Wed Jul 09, 2003 10:35 pm
by dolphinius_rex
oops, my bad! :oops: