PX716SA bad spikes (down to 4x) on write-transfer fest

I’m having major troubles Ironing out write transfer problems on my Plextor PX716SA. I used the Plextools write-transfer rate test on a DVD and while the rate consistenly increases for a while, the rate drops regularly to about 4x! Help!
I have tried it out on two computers, the latest one a DELL Dimension 8400.
I’ll also try to attach the results to the plextor write test.
Any help would be appreciated.

That is normal. It’s PoweRec kicking in because it ‘thinks’ that writing at a higher speed is not safe enough. The first thing I would do, if you haven’t done so already, is to upgrade the firmware of your drive because this will improve the drive’s write performance. Then, if the write speed still decreases and you are sure that the discs will work at 16X with acceptable quality you can disable PoweRec via PlexTools (see the Drive Options). But, this is not recommended because when PoweRec is disabled the write speed might be too high for your media and you can end up with a coaster.

Thanks a lot for your response.
I tried as you said, and disabled Powerrec. This helped, in that it stopped the lower plateau rate drops at the end, but the low spikes persist, most every even numbers (8x, 10x, 12x, 14x, and 15x).
I tried Emailing Plextor support, but so far they only Emailed a generic response.
I"ve attached the resultant test (got the same results twice).
Any further suggestions?

The spikes are normal. This is the drive checking the speeds as part of PoweRec. The drive will stop momentarily to check the data written to the disc and then proceed. With PR on, the drive will drop down in speed as in your first scan if the error rate gets too high. With PR off, the drive still checks but doesn’t drop the speed. The next thing is to check the error rate of the discs. Compare the burn with PR on and PR off. If the error rate with PR off is too high, you need to keep it on for the best burns. Most media defects are on the outer area of the disc, so a burn as in the first posts are normal.

Thanks for your help.
I’ll keep an eye on the error rate…

Do these PR-checks cause ‘gaps’ on the burn?
Or is the 716 able to seamlessly continue where it left off?

I always burned at the ‘lowest common demoninator’ on my old LiteOn because I really hated the wasted space the ZCLV ‘rings’ that you would get would cause.

Good Q.
Don’t know, as I have not burnt it yet (the plextools did that check w/o burning, just the transfer test).

The Plextor burns seamlessly. It’s also not the only burner that does this. Most high speed DVD burners show these “speed-drops”. They are needed to ensure write quality. Also, when burning via the Z-CLV write method there are also no gaps since a gap would result in an unreadable disc. There can be visible darker and lighter rings on the disc. They are the result of the increase write speed and higher laser intensity. This again should not affect the write quality.