To be honest, they both sound the same speed to me.

(And yes I know, I spent too much of my time as a kid playing Descent 2. 😜)

Okay, maybe that wasn't the best example. Here's a better one. Especially at the end.

Does it have an actual FM chip or does it emulate one? If it emulates one then I wouldn't be surprised to hear slowdowns if the driver gets CPU starved.

I thought it did have a real one, but maybe it doesn't. How do you tell?

Took a picture of it (blowing on the picture won't take the dust away!)

http://i31.tinypic.com/df9hch.jpg

Don't see any Yamaha/YMF chips on there but maybe it has a clone chip?

Realtek has some datasheets here: http://www.realtek.com/search/default.aspx?keyword=als100

LS262 may be a YMF262 clone or licensed chip.

I guess it's a clone chip then. It doesn't sound anything like my terrible Sound Blaster PCI 128 card with emulation, but would maybe explain the slowdowns.

I knew I should have looked these things up first before staring with my recordings :(

Interesting to see the clone chip. I did not download the Realtek files as they were Windows executables (not much use on Linux now...)

I had a broken sound card which had a real YMF262 chip but the DAC was a clone with a name of LS-215, very similar sounding to the original YAC-512, just the numbers in different order.

I did not do any in-depth analysis but it seems that the clone DAC is pin-to-pin compatible with the original.

Plus I threw the card away, so I only kept the OPL chipset to myself.

I have done some new recordings with a Sound Blaster 16 CT1740.

Still some slowdowns compared to DOSBox, especially the OPL3 recording. But I guess these slowdowns are supposed to happen then? It would be great if someone could confirm this.

It's the game itself accessing the HD during playback. Go hit F2 into the options screen as soon as you load a level. For better results, play a demo recording then enter options.

They are recorded from the menu, and the hard drive isn't accessed at all from what I can tell. Not even when I did access the hard drive all the time, by constantly switching screen size while demo recording, making the game completely unplayable, it made any difference.

I also did a recording from a demo recording while in the options menu, and I can't notice any difference.