Strange Slow Transfer Rate Graph

Since the last few days, ive started getting a strange TRT graph in cd-dvd speed. The drives starts reading the discs then it suddenly dips down and continues properly from there. this happens with ALL the discs that i have, even with the ones that gave a normal TRT graph, only a week ago. Since it happens in all the discs, i feel that the problem is with the drive rather than the discs. I’ve posted a graph from one of the discs below. The dip in graph occurs at the SAME position for all the discs.

My DVD Burner is SONY DRU-820A, Firmware 1.0c

Thanks.

Thats strange. I would first check to see if DMA is enabled on your drive. Link
You can also check the DMA status on the configuration page of Nero Info Tool.

DMA is enabled. It says Ultra DMA 4

Have you tried reflashing your firmware. Run a burst rate test with CD DVD Speed. If it is running at UDMA 4 is should be above 30 on a DVD.

I havent tried reflashing because i remember getting a perfect graph after the last update. The burst rate is 36.’

I feel that the drives switches to a lower read speed at the same point on the discs. Is there any reason that this could happen ?

Anyways, it reads DVD- ROM discs well. I only get this problem on DVD+R and DVD-R discs…

I have the same drive (Benq1670) and it doesn’t drop off like that. I’ve looked at some other 820A scans and haven’t seen any that drop off like that. They all seem to have a dip in the same area but recover quite fast and are still able to reach 16X at the end. Example
At this point I would try it in a different computer if you can.
Is it still under Sony’s warranty?

Yes it is under warranty. But it will be difficult to get support over here…should i ask for repair/ replacement ?