The KT7A Raid uses the KT133A chipset an update of the KT133 chipset used on the KT7 Raid. It basically allows you to overclock AMD cpus with the Front Side Bus (FSB)over the KT133's stable FSB of ~113MHz. Just know if you attempt FSB overclocking @115MHz the PCI clock runs at 39MHz and thats about the limit for PCI devices, and you really should have PC133 ram if you're going to do it this way.
Also, word of warning if you do overclock: that Abit board and many KT133/KT133A motherboards cannot use some large HSF's, and the only one that can is the Asus A7V/A7V133 motherboards.
I dont know if you will overclock, but I figured this might be helpful in any case.
Keep your ram unless you're going to overclock by the FSB.
The Athlon-C's, which use a 133MHz sdr/266MHz DDR FSB may have to use PC133 to run, but I havent heard anything about it.
 
I hope this clears up some stuff, and doesnt confuse you.
 
[This message has been edited by Brian Frank (edited 21 March 2001).]

I'm almost certain that the KT7A has made a bit more room for larger HSFs, but do more research to verify this - you could always get a Mini-SuperOrb and be safe, or the current OC champ, the Iwill KK66 board [available in RAID: KK266-R], or the 8KTA3 from EPoX, which was well received [also RAID in the 8KTA3+].
 
I would get the KT7A [re: am getting in a month or so], if just b/c they are more likely to have newer drivers for it [being the newer product]. You don't really do justice to an AMD CPU if you don't OC it a bit [or a ton], so you'll want the 133 bus. Also, when you do get above the 115MHz mark, the clock divider changes [to 1/4 I believe], so you won't necesarily be goin to thet 39MHz PCI clcock as suggested [i'm running at 150MHz, so I would be dead if that was true - 50MHz PCI clock = whew!].
 
Althoug, if you already have PC100 memory, and you don't want/need to overclock, then the KT7 should suit you fine [minus the large HSF, which you won't really need if you're not OCing].
 
-bZj