These are relatively unimportant statistics really. L2 cache is processor dependent, so you can ignore it and simply go with the fastest processor of the brand you chose (e.g. P4 or Athlon). (although as stated above, there are special varieties of certain processors, like Intel's Xeon, that have different specs, but for a DAW, we're just concerned about consumer grade processors)
The FSB, as described above, is for all intents and purposes the actual bandwidth available to the processor. It used to be easy in that it was simply the speed between the processor and memory, but things have gotten a little more complex, especially since Intel and AMD are no longer using the same architecture. However, we can simply say that the higher the FSB figure, the more data that can be passed to and from the processor, regardless of the platform.
The FSB is only a moderately important figure. Just about any machine today is going to have memory bandwidth in the 266 (low end DDR) to 533+ (RDRAM) range, and the difference between RDRAM and DDR performance in the real world has not been significant. RDRAM costs more than DDR, so it might be worth your while to look into a system with DDR, which companies will advertise with FSB speeds of 266Mhz (PC2100), 300Mhz (PC2400), 333Mhz (PC2700), or 366Mhz (PC3000). Both intel and AMD systems are available with DDR (but only Intel uses RDRAM).
Now, since you're buying
a complete system, the price difference between DDR and RDRAM might not be that significant. If you get a reasonable P4 system with RDRAM, that's just fine and dandy, it'll work great for you. If you get a P4 system that uses any DDR, then that's just fine and dandy - it'll work great for you as well! Just don't get a system that uses regular SDR SDRAM (e.g. PC133).
On a side note, DDR = "double data rate" and SDR = "single data rate"...although my acronym recollection has been known to be a little off at times
DDR memory is basically the same beast as SDR, except that data can move on both sides of the clock tick. So an SDR module running at 133Mhz gets 133 million clock ticks per second, and gets 133 million chances to speak its mind. A "266Mhz" DDR module, on the other hand, also only gets 133 million clock ticks (133Mhz) per second, but gets twice as many, or 266 million, opportunities to talk. Everything that the processor is going to process is going to be moved to and from the system memory, so if you don't have enough bandwidth, the processor can starve, and you won't realize it's full capability. How much bandwidth is necessary in most cases? Not yet the standard 533Mhz that RDRAM offers. DDR at 333Mhz (166Mhz x 2) is probably a safe bet.
Often times people sweat these somewhat insignificant figures when building a DAW....mostly because manufacturers blow these figures at us as if that's what makes the huge difference in performance....like if you're not careful you'll get a 2.5Ghz P4 with a smaller than normal L2 cache or something, which just isn't possible. It is good that you're looking into these things, the more you know the better, but I hope you concentrate on the big specs first (e.g. get as much processor as you can afford, at least 512MB of whatever memory the system uses, one or two good 7200RPM hard drives, maybe a nice Geforce4 video card, etc)
Slackmaster 2000
