Do you mean that by using the 939 I'd be "future-proofing", as the 754s are on their way out? That's my take on the situation.
Well, I spoke to my tech guy, and he's telling me I still should wait. At this point, I don't know what I should do. I still have the ECS board and 2800 Barton from the ebay guy; spoke to him, and he's trying to figure out how I should get the stuff back to him (or he's probably trying to stay outta trouble with his boss). If I had an extra case, I'd probably slap the motherboard and cpu in. The ECS board supports a 400 Mhz fsb, but the 2800 Barton only goes up to 333. So, I'm thinking, maybe I should get a case, 512-1 gig of pc3200 ram, and simply wait for the prices of both motherboards and A64 chips to go down. I've been reading so much about the A64s, compatible boards, and now the PSUs even have me confused. I can't be quoted verbatim about the 12v rail, could have been something like 20(something)amps, volts, I'm not sure.
So, again, how much of a speed bump you think I'd get going from a 2000+ @266 FSB to 2800+ @333 FSB (w/double the cache @ 512)? Mebbe I can cut a deal with the ebay vendor to just keep the Barton chip, as I have no use for the ECS board. My existing Asus board (which I really like) supports 333 fsb. I figure I'd get pc3200 ram anyway, as I'd probably need it for the future A64 system.
And here's something new: if you look at the tigerdirect site, you'll see all the A64s "with 1600 Mhz FSB". I looked at a few compatible boards with K8T800 chipset, which I thought only supported a FSB of 800. So is this some kind of marketing ploy? I'm trying to make an intellegent decision (for once), but the more I read, the more frustrated I get. At the moment, I just want raw speed. My existing system has served me well, but it takes forever to render a video, and even with the upgrade to an FX5900 XT vid card, I figure the bottleneck must be the chip and my 266 FSB (and it REALLY bugs me that my daughter's system is faster on a micro-atx board with a 2.4 Celeron! (soon to be a 2.8; I pointed out to my techie, that Biostar recommends a 2.8; I spoke to Intel, and they suggested I go with the 2.8 cuz the voltage difference can ultimately fry the board AND chip. Aacck...this whole thing is giving me a migraine.

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