Intel is undergoing something of a transition right now. As it likes to tell journalists, itâ€™s moving from a single-minded gigahertz obsessed company to a balanced, platform focussed company. What this means is that instead of trying to sell you a single product it is going to try and sell you a â€˜solutionâ€™ or rather a group of products that work well together and that will hopefully make your life better. The move to platformâ€™s started with Centrino and continues with Viiv, to be launched in a couple of weeks, which happens to be next year.
In terms of products this shift can be signified by the emphasis away from the Pentium 4 architecture, to new dual-core mobile â€˜Yonahâ€™ processor for notebooks, where Performance per Watt, rather than clock are the benchmarks. By the end of the year, all of Intelâ€™s desktop processors will be based on this style of processor and Pentium 4 will be a distant memory.
The problem with Pentium 4 is that its NetBurst architecture never lived up to its promise. It was meant to go up to 10GHz, but to do that Intel would have had to have supplied a miniature Battersea Power Station with every boxed processor and that just wouldnâ€™t have been practical. The long pipeline architecture never delivered the real-world performance goods either, especially compared to AMDâ€™s Athlon 64. The latest processor from Intel that weâ€™re looking at here can be viewed as the beginning of the end for Pentium 4. Although Yonah was to be the first Intel CPU based on a 65 nanometre process it looks as though the Pentium Extreme Edition 955, previously codenamed Presler, will beat it by a couple of weeks. This means Intelâ€™s latest desktop CPU has the same name as its current chipset, though the new CPU is being launched with a new chipset, the i975, at the same time. Confused? Yes, so were we.
The processor is the second dual-core Extreme Edition processor, the first being the Extreme Edition 840, (codenamed Smithfield). That CPU was based on 90 nanometre process technology and each core ran at 3.2GHz. The shrink to 65 nanometres has enabled Intel to push up the clock speed of the two cores in its flagship CPU to 3.46GHz, and perhaps even more significantly has given it room to squeeze in a lot more transistors for a bumper-sized Level 2 cache. The new Presler CPU features a whopping 2MB of Level 2 cache per core, which you can probably work out, means 4MB of cache for one CPU. Thatâ€™s a lot of cache.
Large though it is, the cache isnâ€™t as advanced as the one featured in Yonah, which sports one large cache shared between both cores. On Presler each core has its own dedicated cache. This is slower than a combined cache as information cannot be shared between cores without going back to main memory, which slows things down. The TDP of the processor is 130Watts. This is quite high and the same as the EE 840. However, when you take into consideration of the extra transistors used in the 4MB of cache, the figure becomes more acceptable.