Hi

I've recently purchased two DVD+-RW drives, the NEC 3540A and the Pioneer 110D. I purchased the two of them to replace my aging DVD-ROM and CD-RW drives simply to ensure that I had two drives capable of double-checking backups made on DVD writable media. I plan to use the NEC 3540A for most of the writing, while using the Pioneer to double-check the media. I will of course use the NEC for disc quality checks, as the default Pioneer firmware (and maybe all others) does not support PI/PIF scanning. Everything appears fine to date and I have experienced no real problems so far.

However, when I write DVD's written on two different media types (+RW Verbatim (MKM something I believe off the top of my head) and -R TDK (RITEKG05)) and scan the discs using Nero CD-DVD, I experience some unexpected results.

In the benchmark image, you will notice that the speed starts to drop off mid-way through the DVD, both the yellow and green lines are affected. The point at which it occurs is variable, but is around that point. This happens on almost every DVD I burn and in both drives, no matter what media it is on. However, I have not notice this problem appear in any other scans posted by people. Is this result relatively normal, or is something amiss here? Only once I have not seen this occur, and the only visible difference between the scanned disc and the others is that the type was detected as CAV. In all remaining cases I have attempted this, the type is detected as P-CAV.

In the disc quality image, you can see a scan of one of my disc burns. Although the results are acceptable by common standards, I'm interested to know why the PI error rate is highest at the start of the disc and lowest at the end. This again is happening on every DVD I burn, so I'm not sure if it is normal or not.

Does anybody have any opinions or ideas on the results? Thanks for your help.

Can you include the images in your post for convinience? There is an option for this, just select edit post and enable the appropriate check-box.

(in reply to Cotun)

My apologies. I tried to do that originally, but couldn't see an option to do so. But now I've found it. Seemed obvious too :)

(in reply to Antonio)

Oh, no problem, I just asked it for more convinience.

The error rates are logical but to be ownest this is something subjective, since the same disc measured in a different drive for error it probably report different quality.

As for the reading graphs in CDSpeed, this show us that the quality is not too good since if it was the drive would read it without to slow down. Did you run any other software during this process?

Get the latest firmware and retry, this might helps 

(in reply to Cotun)

quote:

The error rates are logical but to be ownest this is something subjective, since the same disc measured in a different drive for error it probably report different quality.

Why would you say they are logical? Is it normal to get more errors at first?

quote:

As for the reading graphs in CDSpeed, this show us that the quality is not too good since if it was the drive would read it without to slow down. Did you run any other software during this process?

It does appear to show that the quality of the disk is not first-rate. But most benchmark runs on poor disks shows sharp spikes where reading has become a problem. In this case, it seems to be a more gradual decline in the speed of reading after a certain point, which seems strange. What could cause this? It happens on every disc I burn, on two different kinds of media.

I didn't run any other software during any of the scans.

quote:

Get the latest firmware and retry, this might helps

Thanks for the suggestion, I'll think about doing that :) But somehow I don't think it will solve this particular problem since it seems to be media-independent. Does anybody else have any ideas on what it could be? Anybody else suffered this same problem?

(in reply to Antonio)

"Is it normal to get more errors at first?"

there is no actual rule for this.

Did you have the reader on an external case, this from the CDSpeed graph?

(in reply to Cotun)

No, both DVD writers are inside the internal case. I have thought maybe case vibrations are causing the problem, there is a heavy-duty 80mm fan inside. Although the drives are secured firmly, it seems possible that vibrations are causing problems when writing to the outer layers of the disc. But this is just a theory, it might be completely wrong. Does the benchmark scan the inner or outer parts of the disc first?

Just as a simple question, why is disc quality important? Is it merely to ensure the disc is compatible in a wide range of players, or does it have any impact on data longevity or any other factor?

(in reply to Antonio)

disc quality or writing quality? in simple words, as I think, yes its both you mentioned, compatibility and longivity.

(in reply to Cotun)

Not good on either count then. I wonder how well these discs have been written quality wise. They are obviously not top standard, but how far below. Should I be worried about them?

(in reply to Antonio)

You should worried if the PI were more than 280 and even more if there PO. PI=120 is something you might see in several cases.

(in reply to Cotun)

None of my written DVD's ever exceed PI=280 or PO/PIF=32 (ECC8). This is the benchmark test for DVD's, so I discard any DVD that doesn't match it.

(in reply to Antonio)

quote:

ORIGINAL: Cotun.

In the benchmark image, you will notice that the speed starts to drop off mid-way through the DVD, both the yellow and green lines are affected. The point at which it occurs is variable, but is around that point. This happens on almost every DVD I burn and in both drives, no matter what media it is on. However, I have not notice this problem appear in any other scans posted by people. Is this result relatively normal, or is something amiss here? Only once I have not seen this occur, and the only visible difference between the scanned disc and the others is that the type was detected as CAV. In all remaining cases I have attempted this, the type is detected as P-CAV.

                                                                              
Did you get similar curves in transfer rate test with Pioneer and other drives? If yes, your computer system may be at fault. If no, move the NEC writer to other computer system and run similar tests.

(in reply to Cotun)

quote:

Did you get similar curves in transfer rate test with Pioneer and other drives? If yes, your computer system may be at fault. If no, move the NEC writer to other computer system and run similar tests.

For the same disc created in the NEC drive, yes, both the Pioneer and NEC drives return similiar results. I haven't yet tried to burn a disc with the Pioneer and test it in the NEC, so I'm not entirely sure of that scenario yet, but I will try it.

I suppose another possibility is that my PC is rather old, only a Athlon 750. Maybe it just can't keep up with the reading rate during the benchmark and struggles as it rises. I know it was struggling to do more than 4.0x when I was writing these discs, so it seems possible.

The vibration is also possible. But I can't think of anything else barring this at the moment. It's not the traditional media-drive problem though given the fact that different media generates the same effect. So it must be something more technical.

(in reply to muchin)

I investigated this problem further to try and determine a probable cause. At first, I attempted to write two identical DVD on different media using the Pioneer writer, which is set to slave on the IDE bus. When I ran a benchmark test on the written DVD in both drives, the same benchmark problem appears in both, although the DVD written with the Pioneer had much less PI failures than the NEC. The PIF were also slightly better on both types of media.

I then tried to scan a pre-recorded game DVD. The first I tried gave such inconsistent results that it's not worth mentioning. The second I tried suffered again from the same problem as the written ones. I have added a screenshot to show the results of this, as the disc was dual-layer and I thought the result was particularly interesting.

So I think we can say that the burning of the discs is not likely to be the problem, although it is possible that whatever is wrong may still be affecting the burning as well as the reading of the DVD.

It could still be the vibration, but I checked this out and the case vibration doesn't seem to be as bad as that produced by the drive during a burn anyway. I did notice that during the benchmark test that 8x reads took over 90% processor power to operate. It may not be a coincidence that the reading benchmarks starts to act strangely not long after this in all scans.... Mainly between 9x and 10x. As I only have an Athlon 750mhz, this seems the most likely cause of the problem at the moment.

What do you all think?

(in reply to Cotun)

can you tell us at which recording speed have you burned both discs? The slow CPU (combined with a slow HDD) could be the cause or also if your motherboard has VIA chipset try to install the latest driver pack

(in reply to Cotun)

Well, the last result I gave was actually from a factory-pressed disc, so I don't think the burning element is actually related to the problem. The CPU is pretty slow since I only have an Athlon 750. But the hard disk is a Western Digital Special Edition 7200rpm with 8 megabytes of cache. I don't think that would be considered particularly slow, although it's not top-end when compared to S-ATA drives of course.

I do have the latest motherboard chipset drivers installed, so I don't think that's the problem. It does have a VIA chipset.

(in reply to emperor)