RDRAM is not performing as well as it should yet. Basically it's just too damn fast.

There are reports of many timing issues with current chipsets, and RDRAM is too hard to manufacture (hence the extrememly high price).
I have seen many a benchmark showing a BX-based motherboard with SDRAM matching an i820 motherboard equipped with RDRAM in every area.
It is difficult to say at this time whether RDRAM will take off. Intel is pushing manufacturers and a few of the larger companies are starting to swing but we'll see what happens.
Right now it's not worth the cost.
And there's one more catch. There are flaws with Intel's newest chipsets (i820 & i840) and regular ol' SDRAM. Ha! You can't win. Things are kinda screwy right now to say the least.
Your best bet at this time is still a BX based board with SDRAM. Luckily many of the more innovative motherboard manufacturers are working around these problems by producing BX based boards that support features of the i8xx chipsets like 133Mhz bus speeds, AGP 4X, and ATA/66. Check out
www.abit-usa.com and
www.asus.com
As far as the hard drive issues...as long as you have enough memory, using the same hard drive for recording and applications is fine (the "plenty of memory" - 128MB or more - is to reduce the amount of pagefile use on the drive). The benefit of using seperate hard drives is that it makes reinstalling your operating system and software much easier...although creating multiple partitions on the same drive works fine. Some will claim greater security against disk failure but that makes no sense whatsoever.
Slackmaster 2000