# BenQ DW1640 only burns DL @ 4x

#1

I have a box of Verbatim DVD+R DL that are labeled "2.4x = up to 6x with compatible high speed DVD_R DL drives). Anyway, my DW1640 (firmware = BSRB).

I burnt an ISO that is 7,133,100 KB in 18 min (1,080 sec). If 8x = 11,080 KB/s then 1x = 1,385 KB/s, right? So my drive did it @ 7133100/1080 = 6,604 KB/s and normalizing to the “whateverx speed scale” should be: 6,604 / 1,385 = 4.8x

Why can’t I burn @ 6x with this drive/media?

``````Manufacturer        : Verbatim
Code                : MKM 001
Disc Type           : DVD+R DL (Book Type: DVD-ROM)
Usage               : General
Recording Layer     : -
Recording Speed     :  2.4 X - 8 X
Capacity            : -

Overburn Capacity   : -
``````

I have SATA HDs so it’s not because the HD is slow.

Thanks!

#2

An 18 minute burn on a DL disc IS in the 6-8x speed range - your burner is not burning at 4x. You can’t just do a raw calculation on the burn speed, you have to figure for lead in, lead out, layer change, OPC speed shifts, etc., and the fact that higher burn speeds are not CLV (Constant Linear Velocity) as it is at lower speeds such as 4x, they are CAV (Constant Angular Velocity). For example, a 4x burn takes about 15 minutes, 60 divided by 4=15, as it is a CLV burn. However, a 20x burn is CAV and doesn’t reach 20x except near the edge, so it certainly takes longer than 3 minutes (60 divided by 20), it’s closer to 5-5 1/2 minutes.

#3

Thanks for the info. Guess everything is fine with the setup then.

#4

What burning progg you using?, if Nero you need to modify it to show the real speed.
I get 8x burns with Verbatims.