detail information

The specifications of this drive tell us that it should write both DVD+R and DVD-R discs at 16x. In this portion of the review we will measure the write time for various types of DVD-/+R discs. We will also focus on write quality and media compatibility.

DVD-Writing performance:

First, we shall take a look at the writing technology used for DVD+R and DVD-R writing.

16X DVD+R Writing speed:

The Toshiba SD-R5372 uses CAV (Constant Angular Velocity) to write DVD+R at 16x. This gives an average writing speed of 11.70x and a total write time of 5 minutes and 34 seconds. The Toshiba uses some type of running OPC technology when writing (shown as small dips in the transfer curve above), which should help to improve burn quality. We tested numerous 16X DVD+R discs and this is the fastest result we could obtain. On many of our tests the write speed dropped to 12x near the end of the burn.

16X DVD-R Writing speed:

The Toshiba SD-R5372 also uses CAV (Constant Angular Velocity) to write DVD-R at 16x. This gives an average writing speed of 11.74x and a total write time of 5 minutes and 43 seconds. We tested with numerous Verbatim 16x DVD-R discs, and this is the only disc that completed at full 16x speed.  Let us compare to the writing techniques used by a few other drives.

The ASUS DRW-1604P uses Z-CLV, (Zone-Constant Angular Velocity) to write DVD+R at 16X. This gives an average write speed of 10.29x and a total burn time of 6 minutes and 48 seconds.

The LG GSA-5163D uses P-CAV (Partial-Constant Angular Velocity) to write at 16x speed. This gives an average speed of 12.75x and a total writing time of 5 minutes and 30 seconds.

We can see that the Toshiba drive is faster than the ASUS DVD writer, but a little bit slower than the LG DVD writer. Let us compare the writing time statistics to a larger pool of DVD writers in the table below.

*Actual writing time was only 12x for the Pioneer DVR-A08XLA on 16x DVD+R.

Taking a look at the table, we can see that the Toshiba drive is one of the fastest DVD writers available. The only drives that are faster at 16x DVD writing are the two offerings from LG.

A more important question is; how is the DVD±R/RW write quality of this drive? After all, you do want to be able to produce discs that are readable and useful. Let us find out now!

Write quality analysis:

You should first take note that this is not a scientific and professional way to test the discs. But according to our testing done in the past, we would conclude that there is a clear link between the quality reported when scanning the disc and the playability of the disc in different devices. Also notice that different drives report different amounts of errors. K-Probe was designed to work with Lite-On DVD-Writers. So we recommend using a DVD-Writer from Lite-On. In these tests we use a Lite-On SOHW-1633S DVD-Writer. Remember that scans done with a Lite-On DVD-ROM or Lite-On combo drive can't be compared with the results obtained with a Lite-On DVD-Writer. Also remember that different PI/PIF ECC sum settings along with different reading speeds in K-Probe will affect the result, we use these settings;  PI (Parity Inner) set to summarize 8 ECC blocks, PIF (Parity Inner Failures) set to summarize 1 ECC block, reading speed: 4X CLV (Constant Linear Velocity). Setting the PI sum to 8 and the PIF sum to 1 will give a result that we may compare to the standards for DVD+R/RW and DVD-R/RW.

But what is a good scan? That is a discussion that we don't think will end soon. This is due to the fact that different drives report different amounts of errors, some players are more picky about media than others and many other factors. For comparison purposes we present you with a scan from two pressed DVD discs.

This scan below shows the results from a pressed, Single Layer DVD-Video disc (Ronin DVD).

This next scan shows the result from a pressed Double Layer DVD-Video disc (Lord of the Rings, The Return of the King). Notice the error jump when shifting to the second layer (the error levels actually drop from the end of the first layer to the beginning of the second layer).

If you read below you will see that both of the pressed DVD-discs are well within the standards.

Download the ECMA 267 Standard for DVD-ROM, the ECMA 337 Standard for DVD+R/RW and the ECMA 338 Standard for DVD-R/RW at http://www.ecma-international.org if you want to look at the standards for yourself. Here is some data from the ECMA standards (it is the same for DVD-ROM, DVD-R/RW and DVD+R/RW):

Random errors:

A row of an ECC Block that has at least 1 byte in error constitutes a PI error. In any 8
consecutive ECC Blocks the total number of PI errors before correction shall not exceed 280.

Here we see what a PI error is defined as a row in an ECC block having 1 byte or more containing errors. And that the sum of PI errors in 8 ECC blocks after each other should not exceed 280 PI errors.

But what is a row and what is an ECC block? Again we refer to the ECMA standards. We did not copy and paste everything but if you are interested in further details, please look in the ECMA standards. A row is 182 bytes long where the last 10 bytes contain PI (Parity Inner) information. An ECC block is 208 rows long where the last 16 rows contain the PO (Parity Outer) information. This gives us a maximum possible PI error amount of 208 errors per block and for 8 blocks after each other this sum is of course 8 times higher giving a maximum possible amount of 1664 PI-8 errors. In practical use a disc with 1664 PI-8 errors is unreadable.

According to our tests the specified max PI-8 sum of 280 for good discs seems to be a good guideline, as some readers have problems reading discs when the PI-8 errors are over 300 and most players start to have problems when the PI-8 error level reaches 600 or more.

But what are the PIF errors that K-Probe reports? They are Parity Inner Failures, meaning errors left after PI correction. Only the ECMA 337 standard describes the Parity Inner Failures. So how is a Parity Inner Failure defined? Here is what the ECMA 337 states:

'If a row of an ECC Block as defined in 13.3 contains more than 5 erroneous bytes, the row is said to be 'PI-uncorrectable"."

In theory an ECC block may in the worst case have 208 PIF since every ECC block is 208 rows long. But the ECMA 337 standard goes further and specifies the max amount of accepted PI Failures (uncorrectable errors) allowed on a good disc:

'- In any ECC Block the number of PI-uncorrectable rows should not exceed 4."  

This means that when the PIF sum is set to 1 the maximum error value should not exceed 4. The theoretical maximum value for PIF is 208 errors.

But what makes a disc unreadable? A POF (Parity Outer Failure) error will make the disc unreadable, but K-Probe does not display the POF's.

Notice that there are other aspects such as disc reflectivity, jitter, tracking errors and so on that also will affect the readability of a DVD disc - but for this we do not have measuring equipment available.

Another detail to note is that we have scanned the discs at 4X CLV speed, by lowering the speed to 2X(DVD-R/RW)/2.4X(DVD+R/RW) or 1X the amount of reported errors may drop on some discs. We use the 4X CLV scan speed for all of our PI/PIF tests.

To see if there is a connection between the reported amount of errors and readability of the discs, we also include a transfer rate test reading curve from the NEC ND-3500A DVD-Writer. A small speed reduction near the end of the reading curve is still accepted on good discs, but serious reading problems or reading failures is a bad sign.

Easier explanation on how to read the test results.

Maybe this got too technical, and you are just wondering what to look for in a Kprobe graph?

Use this as a guideline for good discs:

PI (Parity Inner): No larger areas on the disc should exceed 280 PI-8 errors, do not worry too much about high single spikes that exceed 280. Lower error levels are always better.
PIF (Parity Inner Failures): No larger areas on the disc should exceed 4 PIF-1 errors, do not worry too much about high single spikes that exceed 4. Lower error levels are always better.

What about the reading curve? If the graph looks smooth with no dips then the disc should be very good. A small slowdown near the end is acceptable.

DVD+R media compatibility and write quality:

There are a few PIF spikes in the Kprobe scan, but the averages look good and the transfer rate test is perfect. This is a good 16x DVD+R burn.

This 16x DVD+R media from Memorex is only supported at 8x, but the write quality is good. Nice looking Kprobe results and a very smooth CD-DVD Speed reading curve. With these positive results at 8x, we really have to wonder why Toshiba does not support these discs at 16x? We would also like to note that the SD-R5372 burns 8x DVD+R using a P-CAV (Partial-Constant Linear Velocity) technique, which leads to faster 8x DVD+R burn times compared to Z-CLV.

The Kprobe results look relatively good here, but the irregular PIF spikes are somewhat concerning. The transfer rate test had quite a few dramatic drops in reading speed, which illustrates some quality problems. We also burned a few other MCC004 discs that turned out to be unreadable. Toshiba could use some improvements in write quality with these discs.

Unfortunately these 16x discs can only be written at 12x.  PI error levels look good and the PIF average is also good. There are a few PIF spikes here and there, but they are not very concerning. Overall this is an ok result for a 12x DVD+R write.

These 8x discs could be burned at 12x! The quality results are impressive here with Fujifilm branded Taiyo Yuden media. We tested with additional discs and the results were not always this consistent with regards to the good quality.

The first PRODISCR03 disc that we tried burning at 8x had some major quality issues and resulted in an unreadable disc. The 2^nd disc (above) slowed down during the 8x write process (to 6x) and produced an excellent result.

The PI/PIF results are very good and the reading curve is acceptable. The only alarming item to point out is the large drop in reading speed at the very end of the transfer rate test.

Ouch! We have some large PI/PIF spikes near the end of the Kprobe graph and some heavy drops in reading speed near the end of the CD-DVD Speed test. Toshiba could use some write quality improvements with Verbatim media!

Even though the PI and PIF averages look good, there is a large PIF spiking and the resulting disc is unreadable. We tested with numerous pieces of CMCMAGE01 media and the Toshiba had trouble almost every time. This definitely needs improvement! This is one of the most common media types on the market!

The Kprobe scan looks great but the reading curve has some major trouble in the middle and near the end of the disc. These are not the best quality discs but the Toshiba SD-R5372 did an ok job with them.

 DVD+RW media compatibility and write quality:

The specifications of the Toshiba firmware TU55 state that it supports DVD+RW writing up to 8x speeds. We tested with a couple different types of 8x DVD+RW media, but unfortunately none of these were supported at 8x by the Toshiba SD-R5372.

Verbatim 8x DVD+RW, maximum recording speed with this recorder is 2.5x.

Ritek 8x DVD+RW, maximum recording speed with this recorder is 4x.

These are the only two types of 8x DVD+RW media currently available. So where is this mysterious 8x DVD+RW writing capability that Toshiba claims with firmware TU55? We don't know! We could only perform DVD+RW tests at 4x maximum.

PI/PIF results look good and the reading curve is also okay. Note that this DVD+RW disc was unreadable in our NEC ND-3500AG drive, so we had to perform the transfer rate test on the LiteOn SOHW-1633S instead.

Again our NEC ND-3500AG drive could not read the disc so we used the LiteOn SOHW-1633S for a transfer rate test. The results are some very high PI spikes along with a troublesome reading curve. Toshiba could use some improvements with the write strategy on this media.

Other DVD+RW media:

We also tested with two other types of 4x DVD+RW discs; OPTODISCOP4 and INFODISCA10. Unfortunately both of these disc types were only supported at 2.4x maximum write speed.

DVD+R/RW Performance Summary: To be honest we were not too impressed with the overall write quality with DVD+R media. Some discs were written with good quality and some were written with bad quality. Toshiba needs to work on improving the writing quality and supporting more media at certified speeds. For DVD+RW writing, Toshiba SD-R5372 did not support 8x DVD+RW writing on either Verbatim or Ritek 8x DVD+RW even though Toshiba claims that firmware TU55 should support it. 4x DVD+RW writing quality could use some improvement and Toshiba also needs to fix their media compatibility to support the 4x DVD+RW discs from OPTODISC and INFODISC.

Head on to the next page and read about DVD-R/RW compatibility and write quality...