CD Read Speed dips

[glock20rocks]

OK, I've got a Lite-On 48125W drive (VS08 firmware).
A few of the discs I've made suffer a massive speed fall-off midway through the disc. The CDSpeed speed graph is smooth up until the drop off, then the speed climbs back up but the curve is NOT smooth at all.
A surface scan shows nothing wrong at all...and that's the mystery.

The CD's are Memorex 40x discs burned DAO with smart burn disabled (as per another CDRLabs forum member; it's the ONLY way I've been able to burn any disc at 48x w/o errors). With SmartBurn enabled the discs will burn at 40x max and the CDSpeed scan disc show some bad spots (but nothing unreadable). I've since swithed back to Fuji 24x disc, burned at 32x to get my error-free burns. But, any ideas why the speed drop w/o errors?

And how come I always end up with such a long-winded post for such a simple question ?

[cfitz]

Do you have another CD-ROM or DVD-ROM in which you can test those discs with CDSpeed? If so, do they behave the same way? And how do pressed CDs perform when checked with CDSpeed in the LiteOn CD-RW drive?

Are you running the transfer rate test, or the CD Quality test (under "Extra")? Try running the CD Quality test - it shows both the transfer rate and errors. You may find that the slow-down in speed does, in fact, correlate to errors on the disc.

I'm wondering if you have a problem with your drive. You shouldn't need to turn off SMART-BURN to get error-free burns at 40x with quality media. Have you tried the gold standard - Fuji/TY media? My friend's 48125W with VS08 firmware has no trouble burning Fuji/TY media (as well as several other brands) error-free at 48x.

cfitz

[glock20rocks]

The burner does fine with pressed discs and any other CD-R.
I was using the transfer rate test and the Scandisk featuers;
I only had to disable Smartburn to get an error free burn at 48x with the Memorex media. Both Memorex and Fuji/TY 24x discs burn fine at 40x, with no errors. The Memorex when burned at 48x (w/o smartburn) suffers a speed drop off DURNING the burn too; the led goes from red to yellow for a few seconds then back to red.

The speed fall off is still there when I run the test on my DVD drive (an old Creative 6x). Scandisk does show damaged areas on that drive, but my burner does not show any at all. I've seen that with the good TY/Fuji discs on my friends 40x LiteOn. His burner reads 'em perfectly, no slow down or damaged errors, but his LiteOn DVD show damaged spots and really slows down on the discs.

I'm not too worried about not being able to burn at 48x; 40x is plenty fast.
Just the speed falloff w/o any errors on the disc was weird. Guess it's the disc. Won't be burning at 48x with those anymore.

Anyone know where to get WSES? I'd like to take a closer look at those
discs...

At least I know what the problem was; thanks cfitz! For some reason I didn't even think to try it in my DVD drive; the things so old and slow and can't rip very well, so I don't even use it much.

[glock20rocks]

Ok, just did CD Quality Test, lots and lots of errors on that disc. So why the heck aren't the errors showing up in the surface scan!?

Also a lot of the discs I burned last night that scanned fine then are showing tons of errors now. Time to return the burner ?

[cfitz]

Ok, just did CD Quality Test, lots and lots of errors on that disc. So why the heck aren't the errors showing up in the surface scan!?

I can't say for sure, but my personal impression is that CD Quality Test reports errors at a finer granularity than the surface scan. I somtimes wonder if surface scan will report a green block if there are only a couple of errors on the block. Anyway, it isn't unexpected to get different results every time you run a surface scan or CD quality test. You've seen my post elsewhere on this issue. I wouldn't worry about a few blocks (~10) changing from run to trun, but if you are getting dramatically different results, that may be indicative of a drive problem.

Right now I am getting a little confused about what you burned when and the results thereof. Could you make a chart for the slow-witted like myself, containg:

Code: Select all

disc brand, disc manufacturer, rated speed, burned speed, SMART-BURN on/off, errors, speed shift during burn (y/n), speed shift during read (y/n)

The one thing that is making sense is that you are seeing errors now on the disc that slows down while reading. That is what I would expect. Of course, even if you don't see C2 errors, it is possible that there are enough C1 errors (that don't show in surface scan or quality test) to cause the drive to slow down.

cfitz

[glock20rocks]

Well, problem solved: It was a (very) weird software conflict. Kazaa.
When it's running, I get the above problems with the CD-R (plus a few other "bonus" problems, like random resets durning intense IDE activity).
When it's not running, the burner seems to work fine. I yelled at my roommate for installing that spy-ware loaded POS and uninstalled. Burned a few more CD's, all problem free. Don't know how Kazaa causes IDE problems, but it sure does on my system. This is the 2nd time I've had problems with it, and why I dumped it before.

As for the CDs (this is for discs burned WITHOUT Kazaa):

Type Rated Speed Act Burn Spd Surface Scan Quality Check
Memorex 40x 48x (no s/b) Perfect Poor
Memorex 40x 40x 1 Damaged Good
Memorex 40x 24x Perfect Good**
Fuji/TY 24x/40x 40x Perfect Great
Fuji/TY 48x 48x/40x A Few Damaged Good
PNY/CMC 40x 48x Very Poor* Very poor
PNY/CMC 40x 8x Very Poor* Very poor
Sony 32x 32x A Few Damaged poor

*=Some unreadable blocks
**=No errors shown, but lots of minor speed dips spaced apart pretty
evenly. Total errors shown: 197.
Fuji 48x rated discs suffer a slowdown during the burn around the 85% marker. This is where the quality check is showing the most errors.
Fuji 24x discs seem to be the best quality disc I've found so far.
I've taken to burn critcal data at 32x or 24x onto those discs only.

PNY sucks. They produce unreadable blocks even at 8x. Still haven't found a disc that burns 48x w/o errors. Thought I had one in the Memorex, but....

Gotta try the Verbatium's still, though.

Thanks for the info!!