UDMA-2 vs. UDMA-4

I have had a BTC 1004IM for several years and it has served me well.

I ran into some difficulties before when I attached it to my MB (ECS KT600-A) with 80 wire cable and it was detected as UDMA-4 or 5. It’s the master on the secondary IDE channel. When I played DVD movies I saw a lot of garbled pictures on the screen. When I re-connected with 40 wire cable, it was detected as UDMA-2 and worked perfectly, garbled video problem gone.

I believe the BTC 1004IM supports up to UDMA-2.

Now I am recently adding a new burner to my system. Its an OEM Benq DW1670 16x Dual layer which I got a great deal on at Staples. Now, I hooked it up with the 40 wire cable and both drives are in UDMA-2 mode. I left it plugged into the secondary channel and the BTC is the master and Benq is the slave.

I believe the Benq DW1670 supports up to UDMA-4.

Here is the spec of my MB (ECS KT600-A):
Support by VIA® VT8237

– 4 x Ultra DMA133/100/66 devices

Couple of questions:

  1. Is UDMA-2 going to be too slow for my new Benq 16x drive and will it cause me some problems if I start burning discs on the Benq at 16x?

  2. If I hook up with the 80 wire cable, and both drives change over to UDMA-4 am I going to run into the same problems I saw before with the BTC garbled video playback?

  3. If I switch over to primary IDE channel will it have any impact on the BTC garbled video playback issue? I can’t remember if I ever tried switching over to primary IDE Channel or not.

I’d really like to have both drives working at the same time!

Thanks for any help!

I just did some searching, and it seems perhaps I should be putting 1 DVD burner on MB primary master channel and 1 DVD burner on MB secondary master channel with no slaves. Then the BTC will be UDMA-2 and the Benq will be UDMA-4. Then move all my HDs over to my PCI controller.

Assuming I can still boot from the PCI controller, I think I am going to run out of channels on my PCI controller because it only has 4 channels and I think I have 5 HDs. So I probably cannot do this without losing a hard drive or getting a new PCI controller. That’s not much of an option since I am out of PCI slots too!

Hi & welcome to the forum.

So what’s wrong with a HDD sharing a channel with a burner? Providing you don’t try to burn from an HDD to a burner that are sharing the same channel then you should have no issues.

Also , unless you do disc-to-disc copying then 2 burners on the same channel should not be an issue. My 2 UDMA mode 4 burners each share with a mode 2 burner.

Maybe your previous problem was caused by a faulty 80wire cable.

Hi Tim,

I tried two different 80pin cables - using either one I got the same problem. Both burners are running in UDMA-4 mode, but the BTC is only supposed to support UDMA-2. When the BTC runs at UDMA-4, DVD’s are not playable in either drive.

I wonder if I can just run the Benq 16x at UDMA-2 and it will be fast enough to burn Discs at 16x?

I checked I have 5 hard disks so I’ll have to share one of the ide channels with a hard disk and dvd burner if I start moving the burners around to different channels or to my PCI controller card.

It’s quite probable that the burners won’t work on the PCI card so I’d try with the MB Primary channel with an HDD & burner and the Secondary channel likewise. Both with 80wire cables.

UDMA mode 2 is fine for 16x burning as currently most 16x burners run in this mode, but some mode 4 burners only work properly with 80wire cables & mode 4.

Thanks for all the advice. I went back to the 40 wire cable and both drives were seen by Windows as UDMA-2. I just didn’t want to have to remember which hard drive lived on the same channel as a dvd burner and avoid burning from the same channel. Hopefully Benq will burn ok at 16x while in UDMA-2 mode. I burned 1 disc but haven’t checked it yet but it only was an 8x disc. I guess if I get buffer underruns during a 16x burn I will notice on screen.

I wonder if root cause of the problem is in the BTC burner or in the Via chipset. When I bought the BTC drive it came with this 40 wire cable so maybe they knew about the issue. Strangely, my Benq came with no cable and no screws! Luckily I have lots laying around fromm hard drives.

Maybe the BTC incorrectly accepts UDMA-4 mode but generates too many CRC errors, just a guess at what is going wrong.

Finally I though about flashing my BTC 1004IM to 1008IM in hopes it would support UDMA-4 correctly but a quick search, I see no evidence that 1008IM supports UDMA-4 either.

The BTC would have come with a 40wire cable as that’s all it really needs to support mode 2 burning.


I agree with pretty much everything TimC has suggested.

I would like to add that the problem with connecting an 80-conductor cable to your BTC drive is most likely a bug in that drive’s firmware, if that drive is only supposed to support UDMA-2.
I have 3 UDMA-2 optical devices and all run fine with an 80-conductor cable and all are recognized as UDMA-2(not 4).
AFAIK, the extra 40 conductors(in the 80-conductor cables) are all grounds to improve signal quality and transmission clarity.