Pioneer DVR-111D - Drive Dying? - CDSpeed Results Inside

For the past couple of weeks I've been getting DVD-R coasters burning at the max. (16x) on my DVR-11D. They are gradually becoming more frequent. Today I had 3 in a row at 16x before dropping to 8x and being successful. Also, each failure comes at the very end of the burn in Nero. Something about cache.

I'm half-way through a 50-disc spindle, so it's not like it's the start of a bad batch of discs. Still, I'm wondering what people's opinion is on the health of the drive?

I just finished a Nero CDSpeed test and to be honest, I have no idea how to read it. I was hoping for something obvious. Write speed not getting close to 16x, but it reaches that level towards the very end. Not sure if the gradual uptick is normal. Here's a screencap:

thats what its supposed to look like. you probably have bad media.. try a different brand.

Thanks for the comment. Rather than a new brand though, I'll just ride the rest of this cake out at 8x and give the next one a go at 16x. I've been using TDK for ages without issue, so if it is bad media then perhaps it's just a bad batch.

Thanks for the comment, but like the media one previously, I've been using the same burning apps (and media) for years with no problem. I should've mentioned that before. So that's why my problems are probably with this specific batch of TDK media or the drive. And I really think it's the drive now...see below