The name game
If you follow our website (or the CPU industry in general) regularly, you've probably heard the word "Thunderbird" mentioned from time to time. This was AMD's codename for the variant of Athlon with integrated L2 cache.
We now know that the Thunderbird core will be branded under the name "Athlon processor with performance-enhancing cache memory." Clock speeds available at launch will range from 750-1,000MHz (1GHz) in 50MHz increments. Like previous Athlon processors, the system bus will run at 200MHz, and the manufacturing process is still 0.18-micron.
These new Athlon processors will be made with both copper and aluminum interconnect technology. Copper processors will be manufactured at AMD's Fab 30 facility in Dresden, Germany while Athlons with aluminum interconnects will be manufactured at Fab 25 in Austin, Texas. With both facilities online, AMD has the capacity to manufacture approximately 11,000 wafers each week.
Which Thunderbird should I buy?
In terms of performance, there will be no difference between the aluminum or copper version of Thunderbird. Likewise, the thermal characteristics of both processors is the same. Don't expect the copper variants of Thunderbird to overclock any higher than aluminum models. AMD explicitly stated that both the copper and aluminum processors should scale to higher clock speeds equally well and doesn't expect copper interconnects to scale higher than aluminum interconnects until AMD transitions to 0.13-micron.
By comparison, Intel has stated the same and doesn't expect to transition to copper and the 0.13-micron manufacturing process until next year.
Basically, if your friend tells you to accept nothing less than a copper Thunderbird because it overclocks higher than an aluminum Athlon would, politely nod in the affirmative and look in the opposite direction. (Or as the saying goes, let the words go in one ear and out the other)
So what should we expect from the integrated L2 cache? The first answer is easy - more performance - but integrating the L2 cache on the processor brings one important deletion, that being the external L2 cache SRAM chips included in the Slot A packaging.
Since the L2 cache is now integrated on the processor die itself, the external cache chips are no longer necessary. This allows AMD to revert back to the cheaper socket interface currently used by their K6 family of processors.
Plug it in
Don't plan on installing a Thunderbird processor on a Super 7 motherboard however. You'll need a Socket 462 (also known as Socket A) motherboard to run successfully with Thunderbird. For OEM's AMD will manufacture a Slot A variant of Thunderbird, but this model will never hit the retail channel. That's right, if you were hoping to install a Slot A Thunderbird in your KX133 or AMD-750 motherboard, you're out of luck.
Complicating matters for current Athlon owners, no manufacturer has announced plans to release a Socket A to Slot A adapter, but we wouldn't be surprised if one eventually hit the retail market.