It becomes clear that
- A64 939 platform has close to four time the max system bandwidth of an XP platform (two from max memory bandwidth and two from max HT bus bandwidth)
- A64 939 platform has close to two time the max memory bandwidth of an A64 754 platfom
We can live with slower CPU, slower system with less system bandwidth, we have been there before from Thunderbird, Palomino, Tbred A, Tbred B, Barton, mobile Barton, .... We know how to tradeoff price and performance, pick and choose whatever we feel comfortable in terms of cost and performance. There had not been a problem since these CPU's and motherboards are all COMPATIBLE, from PC 100, PC 133, DDR 266, DDR 400, over 6+ years (if I remember the time right).
The problem that has been created for us is the multiple platforms for the new A64, three of them, 754, 939 and 940. They are not compatible and if we commit to one, we have to completely get a new set of CPU and motherboard to change over. Let say CPU+mobo $400 each time, it would take $800 total to change over if making a wrong choice, a big concern for most of us. Imagine we have to get (not we choose to) a different motherboard for each Palomino, Tbred, Barton upgrade !!!!
So I think unless I don't have any hardware/computer now and needed to build one yesterday, I would wait until at least May or June, hopefully, the picture for 939 CPU, nforce3 250 gb motherboards, .... become clearer for making a decison for either 754 or 939.
If we can wait, I think best time to upgrade seems to be towards end of this year or even next spring, the dust and price for the 64-bit OS, 130/90 nm 939 CPU (yield and price), video card, motherboards, HT devices, ... will settle more to our favor.