DVD-RAM writing performance

BenQ DW1800 supports reading and writing the DVD-RAM format.

DVD-RAM is a veteran among the three DVD formats. It is a ten-year old format, and it predates the DVD-R format by one year.

The DVD-RAM format is inherently more reliable than other DVD rewritable formats due to its superior error control, defect management, and the option of hardware data verification during writing.

DVD-RAM defect management provides data structures, stored on each disc, that allow unusable sectors to be relocated. It also allows the number of relocated sectors to grow over time, effectively reversing the negative effect of gradual media deterioration.

Looking at the recording side of a DVD-RAM disc, it is easy to notice that the data surface is very different from DVD+R and DVD-R discs. It has a pattern of small rectangles not seen on any other recordable DVD media:

DVD-RAM recording surface

The rectangles are embossed (pre-recorded) areas that contain addressing information and other sector header data. The data portions of track sectors cover the remaining bulk of the surface.

A 4.7 GB DVD-RAM disc is divided into 34 zones, each comprising 1,888 tracks. The number of sectors increases from 25 sectors per track in the innermost zone 0 to 59 sectors per track in the outermost zone 33. This track layout explains the pattern we see on the recording side of a DVD-RAM disc.

In our setup, running on Windows XP with a DVD-RAM driver installed, a DVD-RAM disc can be formatted in any of the following formats: FAT32, UDF 1.5, UDF 2.0, or UDF 2.5:

DVD-RAM format choices

Formatting a DVD-RAM disc takes only a few seconds:

DVD-RAM format confirmation

DVD-RAM format progress

DVD-RAM format complete

Once formatted, DVD-RAM appears as one of the drives among other storage devices:

DVD-RAM drive

DVD-RAM drive properties

Many operating systems (Mac OS X, Windows XP, Windows Vista) support DVD-RAM formatting, reading and writing directly, without the need to install any additional drivers or software. Once a DVD-RAM disc is formatted, it acts like a removable hard drive and all writing is done in the background. This means that you do not have to wait for the drive to finish writing and can continue working with applications while the DVD-RAM drive is doing the burning.

In the tests below, we will explore DVD-RAM writing by BenQ DW1800 with media from several manufacturers.

Maxell 12x DVD-RAM

Maxell 12x DVD-RAM
(Thanks to ExtremeMhz for providing this media)

Disc information

Disc creation test (without verification)

Transfer rate test (Lite-On SHM-165P6S)

Disc creation test (with verification)

Transfer rate test (BenQ DW1800)

12x DVD-RAM media is scarce and expensive but performs very well. BenQ DW1800 writes a full 12x DVD-RAM disc in 5 minutes and 45 seconds (without verification), and reads it back in 5 minutes and 36 seconds.

Please note how turning on data verification has slowed writing speed from an average of 10.05x to 3.78x. This is due to the drive constantly reading back the data after writing it, to verify that it has been correctly stored. It is a slow writing technique but in combination with the defect management mechanism of DVD-RAM it is as close to "bullet proof", in terms of preventing data loss, as one can get with optical media.

Maxell 5x DVD-RAM

Maxell 5x DVD-RAM
(Thanks to Maxell USA for providing this media)

Disc information

Disc creation test

Transfer rate test (Lite-On SHM-165P6S)

Transfer rate test (BenQ DW1800)

A trouble free 5x DVD-RAM experience. Good to see that 5x DVD-RAM is written using the faster 5x CLV strategy. However, reading is still done at 3x-5x P-CAV.

Memorex 3x DVD-RAM

Memorex 3x DVD-RAM
(Thanks to Memorex USA for providing this media)

Disc information

Disc creation test

Transfer rate test

A reliably working 3x DVD-RAM media.

Verbatim 3x DVD-RAM

Verbatim 3x DVD-RAM
(Thanks to Verbatim USA for providing this media)

Disc information

Disc creation test

Transfer rate test

This is the same Panasonic-manufactured media as above, this time Verbatim-branded.

DVD+R DL and DVD-R DL writing quality

Advanced tests