It is this chip that will take Intel through to its dual core Montecito processor debut in the second half of 2005.

According to the rumor mill earlier this year, this updated Madison processor was expected to come out around the September Intel Developer Forum, and it was expected to have around a 1.9GHz clock speed in the largest cache version, which has 9MB of L3 cache on chip.

As is normally the case, Intel also planned to sell slower variants of this chip with smaller L3 caches, mainly because the yields are better on these processors. This is how all chip makers do it – they get small yields on their best performing processors and charge a hefty premium for them, and they get better yields on slower chips and they charge a lower price for these.

The word on the street this summer is that Intel would offer Madison kickers running at 1.8GHz and 1.7GHz, and possibly with smaller caches on one or both of these.

Adam Martin, enterprise marketing manager for Intel’s EMEA group, said that the top-end kickers to the Madison chips were coming out at 1.6GHz with the 9MB cache because, quite simply, the yields on the 130 nanometer process used to make the Madison chips were not good enough at the higher clock speeds. And when asked if we can expect to see higher clock speeds on the Madisons as yields improve (as they always do), Martin said that this was pretty much it for the Itaniums until Intel rolled out the dual-core Montecitos.

While he did not say this, it is also true that customers are increasingly concerned about the power consumption and heat dissipation issues of large chips like the Itanium, and even if Intel could get good yields on the large-cache Madisons, they may have run too hot to be useful except in the largest machines from Hewlett-Packard Co, NEC Corp, and Bull.

Intel is now launching three different variations of the updated Madison processor: one for four-way and larger server configurations, one for two-way machines, and another for blade servers where power is a big issue.

The main chip that enterprise server makers (such as those mentioned above) will be interested in are the 1.6GHz/9MB cache version of the Madison, which is a so-called MultiProcessor or MP version that is designed for four-way motherboards and cellboards used in larger SMP machines. This chip has a 400MHz frontside bus and it cranks out about 130 watts of heat. It is plug compatible with the existing Madison chips (as will be the future Montecito).

Martin says that on transaction processing workloads (such as those typified by the TPC-C online transaction processing benchmark test), this chip will yield about 15% more oomph than the current 1.5GHz/6MB cache Madison chip, and that on number-crunching workloads where cache and memory bandwidth matter more, performance will be about 25% higher than on that 1.5GHz part.

He says that on average, customers should expect about a 20% performance increase. And with the chips selling at the same price as the prior Madisons, that translates into a 20% improvement in price/performance at the chip level. If Intel had pushed the clocks to 1.9GHz, it might have been able to get a 30% performance improvement, and heat dissipation might have gone as high as 155 watts. It costs $4,226 in 1,000-unit quantities.

Intel is also shipping versions of the MP Madison chip that run at 1.6GHz with 6MB of cache ($1,980) and that run at 1.5GHz with 4MB of cache ($910).

In the two-way server space, the new Madison DP processors run a 1.6GHz with 3MB of cache on the chip. They come in two flavors: one with a 400MHz frontside bus that can plug into existing Itanium servers without changes to the chipset, and another that has a faster 533MHz frontside bus that will require chipset changes.

This latter chip is clearly aimed at customers in the high-performance computing market, who like to use Itanium chips because of their superior number-crunching ability but who do not need big caches and who will not pay thousands of dollars for a chip.

The Madison DP with the 400MHz bus costs $851 (replacing an existing 1.6GHz/3MB part that cost $2,048, and exactly how this one is different is totally unclear), while the Madison DP with the 533MHz bus costs $1,172. Both of these Madison DP chips dissipate about 99 watts, and Intel says that they offer the best floating point performance for the dollar in the Madison line.

For entry servers, particularly blade servers where low power consumption is key, Intel is also rolling out a Low Power, or LP, variant of this iteration of the Madison. This one has a 400MHz frontside bus, a 1.3GHz clock speed, 3MB of L3 cache, and it dissipates 62 watts. It costs $530 in 1,000-unit quantities. This chip has 30% more clock speed and twice the cache of the prior Madison LP chip, and for the same price.

By the way, Intel is not planning on dropping prices on earlier the Madison chips. So don’t think there will suddenly be great deals on the existing Madisons as Intel ramps up production on the new chips.