External BenQ drive




I intend to attach a BenQ DW1650/1655 to my notebook.

The FAQ says:

“… most experiences with BenQ drives in an external enclosure are disappointing, as the drive can usually not reach the full 16x speed, when reading or burning.”

Is this (still) true for the 1650/1655?

An alternative of building an own setup could be the BenQ EW164B. The technical data look identical to 1650. I sent an email to BenQ, but didn’t get an answer (yet). Can anybody confirm if they are identical, and share some experience with the drive?

The advantage of an own setup is that I could choose an enclosure with Firewire connect, because all my notebook’s USB connects are more or less occupied, but Firewire is unused so far.

Many thanks for any help.

Best regards



This drive case should work (ask Dealsonic) but you would need to update to the latest Prolific firmware to be sure as there were problems with the 1640.



You would need to flash the 3507 chip with USB as notebooks don’t generally have 6 wire firewire and won’t flash without it.


The main problem with using a BenQ in an external case is that it needs to work in UDMA4 to allow full 16x speed to be reached using firewire.

The BenQ 1650/55 only have firmware that allows UDMA2 to be used and as such cannot hit 16x, they are limited to 12x or slower. I personally do not class this as a problem as there is only about 30 seconds difference between a 12x and 16x burn.

As soon as they release an external 165x then we will have firmware that will allow UDMA4 and can then hit 16x.

The 1640 already has an external firmware and as such it can hit 16x in a Prolific case



EW164B is an external version of DW1640. There are some threads about crossflashing DW1640 with EW164B firmware.



@chas0039, @qwakrz

Thanks for your feedback.

I spent this afternoon to find out more about the performance of external drives. Finally, I came across a test in German computer magazine c’t 8/2005 where the following results were reported:


Though in German, you can get an idea of the performance of the tested cases if you look at the three lines following ‘Messungen’ which give read transfer rate, write transfer rate, and max. burning speed that can be reached under USB resp. FireWire. Best results shows Mapower MAP-KC51C1 due to the used chipsets (Genesys GL811E-04 for USB, Oxford911Plus for 1394a). Perhaps easier to read is the following graphical summary


which clearly shows Oxford911Plus to be the most performing chipset. Surprisingly, it even surpasses all USB chipsets’ read and write performance (except Genesis Logic GL811E-02 which equals in write speed but is far inferior on reads). c’t summarizes that MAP-KC51C1 can burn at 12x with USB and 16x with FireWire.

The superior performance of Oxford911Plus is backuped by the following very detailed article:


I don’t know how all these results relate to the lacking UDMA4 support of DW165x. On the other hand, I agree that 16x isn’t really an issue: I prefer quality burns to highspeed burns, and at least for the moment most experts recommend to burn 16x media at 12x.

Unfortunately, the German Mapower site recommends not to use BenQ drives with MAP-KC51C1 on Oxford bridges. I’ve sent a email and asked for details. I’ll keep you informed.

If there are really incompatibilities with DW165x, which alternatives should I look for: LiteOn, Plextor, NEC? Any recommendations?

Best regards



The Oxford 911 Plus is a 32 bit chip. Let us know if you ever find one in an external case. Most bridgeboards I have found use the 922 or some other 1394b firewire 800 connection.


I don’t have any first-hand knowledge of the BenQ, but I have two external enclosures with Prolific PL3507 chipset, and I have tested a NEC 3500, a NEC 4551 and a LiteOn 1635 in these enclosures.

[li]All drives are able to reach 16x reading speed over FireWire.[/li][li]Only the LiteOn drive is able to reach 16x writing speed over FireWire.[/li][li]Only the LiteOn drive is able to reach 16x reading speed over USB.[/li][li]Only the LiteOn drive is able to reach 16x writing speed over USB.[/li][/ul]The LiteOn drives use UDMA4 where most other drives use only UDMA2, and this makes a big difference in an external enclosure.

So I can definitely recommend a combination of a LiteOn drive and a Prolific PL3507 based enclosure.


Mapower MAP-KC51C1 should have it, according to c’t test results and to mapower’s (German) homepage.



As to LiteOn drives, this sounds very promising. I don’t know if SHW-1635S is still available as SHW-16H5B is already introduced which seems to be its successor. I also don’t know if a jump to LiteOn’s 6th generation (SHW-160P6S, SHW-160H6S, other models with DVD-RAM support are not of interest for me) is worthwhile thinking about.

Another option could be Plextor PX-755A. Any comments?

Your remarks concerning Prolific PL3507 clearly fit into the c’t test results, as its transfer rates are very close to the winning Oxford OXFW 911Plus. Which enclosures do you use?



See post 2 above for a Prolific 3507 enclosure.