DMA handling
 

I am working in Mandrake 9 on a data acquisition program involving DMA. My company has discovered experimentally that under windows 98, we are limited to a 32 MB DMA buffer size. Our company has thus switched to a linux approach. We have found that under linux there is a problem if we create a buffer size any larger than 128 MB. Currently, our approach is to create two smaller buffers and to switch back and forth in a ping pong fashion writing data to one while the other data buffer is being written out to file. With large file sizes (>128 MB) we are still discovering a data corruption problem. Is there any known limitation to 128 MB data file sizes? Is there a way to change a setting in the kernel to allow for larger DMA buffers and file sizes? Also, does anyone know how to set up a large ramdrive under linux? I am having difficulty creating a good ram drive with linux.

Thanks,
Ricky