PI/PIF/POF Spike With NEC ND-4550A

by **Ian** on Sat Nov 05, 2005 10:53 am

I'm guessing there aren't a lot of people with the NEC ND-4550A.. and even fewer with it and the BenQ DW1640A.

Anyway, when scanning discs burned by the NEC on the BenQ, I'm seeing a PI/PIF/POF spike at the 2.25GB mark. I'd say this is happening with about 70% of the single layer DVD+R and DVD-R media I've tested. As you can see, this causes a dip in the transfer rate graph. Of course, when scanned with a Lite-On drive, there is no spike at all. :roll:

These discs have all been burned at 12x or 16x. I still need to slow it down to see if it happens at 8x or lower.

Thoughts?

by **RJW** on Sat Nov 05, 2005 1:29 pm

Hmm would be a ideal candidate to pull through one of these overpriced profesional analyzers to see if there's anything which causes this behaviour.

by **carl** on Sat Nov 05, 2005 6:24 pm

I've seen the same thing on the 35XX hardware.

by **Ian** on Sat Nov 05, 2005 7:51 pm

carl wrote:I've seen the same thing on the 35XX hardware.

Really? I didn't see spikes like this. Then again, I tested those with the DW1620. Maybe I should try a few of the discs with it.

by **Dartman** on Sat Nov 05, 2005 8:13 pm

My 3500 doesn't do spikes like that either. Could be a anamoly with the 1640
and error testing maybe. They also claim the funny spikes at the end of some 16x burns aren't really there so who knows. Try the 1620 again and see if it's the same. I spose as long as the disk works...

by **ala42** on Sat Nov 05, 2005 8:26 pm

Benq drives are quite jitter sensitive. 15.8% is too much for the drive, causing the PIFs which other, less jitter sensitive drives do not see.

by **Ian** on Sat Nov 05, 2005 8:55 pm

ala42 wrote:Benq drives are quite jitter sensitive. 15.8% is too much for the drive, causing the PIFs which other, less jitter sensitive drives do not see.

Good point. The question then is what's causing the jitter to spike there? On average, the jitter is between 9-11 on most of the discs.

by **Gabe** on Sat Nov 05, 2005 10:02 pm

ala42 wrote:Benq drives are quite jitter sensitive. 15.8% is too much for the drive, causing the PIFs which other, less jitter sensitive drives do not see.

Yeah, Benq-drives don´t like higher jitter and shows sometimes very high PIF in critical jitter-zones.

But the LiteOn shows these spikes, too, and LiteOn isn´t very sensitive when a media have higher jitter.

But these spikes are sometimes on media that´s burned with my NEC 3500 (and some other NECs, too)

by **Ian** on Sat Nov 05, 2005 11:57 pm

I think some of you guys are confused about the spike I'm referring. I'm not talking about the PIF spikes you see when testing with Lite-On drives. I'm talking about this one:

by **Ian** on Sat Nov 05, 2005 11:58 pm

For those wondering, if I slow the writing speed to 8x, there is no spike. I'm gonna have to talk to NEC about this one on Monday.

by **dolphinius_rex** on Sun Nov 06, 2005 2:41 am

Ian wrote:For those wondering, if I slow the writing speed to 8x, there is no spike. I'm gonna have to talk to NEC about this one on Monday.

Maybe it's time I called in a favour with the Pro testing equipment? Of course, I'll need the actual disc in question :wink:

by **ItalianJob** on Sun Nov 06, 2005 6:00 am

As pointed ala42, the jitter reported is horrible #-o

by **Gen-An** on Sun Nov 06, 2005 10:14 am

YSS's tests show something similar:
http://homepage2.nifty.com/yss/nd4550a/ ... vdben1.htm
http://homepage2.nifty.com/yss/nd4550a/ ... vdben1.htm

by **RJW** on Sun Nov 06, 2005 11:56 am

The data on YSS shows that it's between two calibrations points.
Also with 8x this seems to fall exactly in a calibration zone unlike 12x and 16x.

All we now know is that the benq reports higher jitter at that point which results in higher errors.

by **jsl** on Sun Nov 06, 2005 1:12 pm

Ian wrote:Really? I didn't see spikes like this. Then again, I tested those with the DW1620. Maybe I should try a few of the discs with it.

Perhaps not as bad as the spikes in your scans here but all NEC drives have given spikes for CAV burns when scanned on BenQ drives. Example from your ND-3520A review:
http://www.cdrlabs.com/reviews/images-view.php3?imageid=8165
The same thing could also be seen with 16x CAV burns from the Pioneer DVR-109:
http://homepage2.nifty.com/yss/a09j/a09jdvd16x.htm
DVR-110 doesn't seem to give these spikes though.

by **Ian** on Sun Nov 06, 2005 9:43 pm

For those wondering, there's also a spike when writing at 12x (actually 13x).. just later in the session.

Looking at the test results, the spike seems to occur when the drive reaches a certain writing speed. It's hard to tell, but it looks about 12.25x-12.5x.

by **dolphinius_rex** on Sun Nov 06, 2005 11:13 pm

When you do a transfer rate test using the NEC itself, does the error show up at all? (i.e. a dip in speed?)

by **ItalianJob** on Tue Nov 08, 2005 5:09 pm

The maximum jitter is again very impressive : 18%

And PO Failures #-o

PI/PIF/POF Spike With NEC ND-4550A

PI/PIF/POF Spike With NEC ND-4550A

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