If prefetching was available in Tualatin Celerons, then quite apparently not all of them:
http://www.realworldtech.com/page.cfm?A ... 231808&p=6
Unfortunately it is not stated which stepping was used.
There have indeed been PIII Xeons with 256K L2, but those were the "budget" models and most probably contained an ordinary Coppermine core (only went up to 2 procs, too, IIRC). That large L2 caches are beneficial in multi-processor operation with a shared processor bus has been shown by Intel years ago (and makes sense, too). In fact, the Xeons (or were it PPros?) with the biggest caches were specifically intended for 4-CPU configs with their very busy FSB. (4-CPU configs with Xeons also required 100 MHz max FSB clock, as if the bottleneck weren't tight enough at 133.)
This tip with AM2 is interesting. It would seem, however, that it's "reserved" for CuMines but grounded (Vss) for Tualatins, with no differences between MP and non-MP versions of the latter. Can also be left unconnected according to both datasheets. I'd check for connection to a known Vss pin, and if that should be present, then obviously it's not this pin (since 'unconnected' has already been tried with no luck). I'd guess BR1# is just not routed to X2 with the Celerons, or if it is, it's pulled up internally (as with the SEPP Celerons). I've never heard of any working SMP config with Tualatin Celerons either, except for those funky 900 MHz samples with the s-spec of 1300 MHz ones that someone got at a fair (possibly a production error struck here, leaving several internal connections open).
BTW, this is one of the least busy threads I've seen, ever. Come back a few months later and you won't have missed more than a post.
