(I posted this over in the k3b.org forum also, but it doesn't seem as active over there as here)

I've got k3b setup to use as much RAM as possible when burning. It only allows me to set it at 2GB, and that's it.

Unfortunately it seems to use that up pretty quickly when burning a 25GB BD-R. For example, when it gets (usually) to about 10% done of 100%, the 'software' buffer will begin to go from 100% down to 0% in just a few minutes and the burning will slow down from ~40MB/s to ~12MB/s because it's stuck with only the hardware buffer.

Once in a while at around 60% finished, the software buffer will start to rise again to 100% but within only a few seconds of it reaching 100% it will start to go down again until it's using the hardware buffer again.

Does anyone have any idea(s) what I can do to have k3b use and *keep* the software buffer up during the whole burning process? As it is, 23GB onto a BD-R takes on average ~25 minutes. If it could keep the software buffer up during the whole burn process, it could probably cut that time almost in half. I have 4GB of RAM available, so it's a shame it has to fall so quickly and get stuck using 4MB of hardware buffer.

Slackware 14.0, AMD FX-6300 3.5GHz cpu, ASUS M5A97 LE R2.0 mobo, Crucial Ballistix 4GB DDR3 PC3-14900 RAM, LG WH14NS40 14X Blu-Ray Burner

"If it could keep the software buffer up during the whole burn process, it could probably cut that time almost in half."

Actually the limiting factor is the speed of the burner. As long as you have enough software buffer to keep ahead of the hardware buffer (and you do) then the size of the software buffer is irrelevant to the speed of the burn.

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Steve Stites

If the software buffer is underrun while burning this is a sign that your storage subsystem is not able to deliver the data to the software buffer with the necessary speed. So either reduce burning speed or use a faster storage subsystem.