Source: [RANK="www.tomshardware.com/cpu/20050221/prescott-04.html"]Prescott Reworked: The P4 600 Series and Extreme Edition 3.73 GHz[/RANK]Originally posted at Tom's Hardware
The 3.8 GHz version Pentium 4 670 will be added later.
With the introduction of the 600 series, there are now 21 individual Pentium 4 CPUs - a rather imposing number of models. Six of them are 500 series CPUs carrying the suffix "J" and offering XD bit virus protection under Windows XP with Service Pack 2 installed. All 500 series versions at 3.0+ GHz are also available with a model number ending "-1," representing EM64T capabilities. Also, there are 19 Celeron models, seven supporting EM64T and XD, twelve with XD support only, and seven without either feature.
Is it really necessary to release that many products? While most people would say no, Intel would argue it's necessary to answer all the different demands out there. What we can say for sure is that it is getting more and more difficult for the end user to get a good understanding of all of the available products and options.
Thermal Specs Remain Unchanged
The introduction of the 600 series did not cause any changes to Intel's so-called "thermal envelope." Most P4 processors fit into the standard class that is designed for a TDP (thermal design power) of 84 W. The high performance models at 3.6 and 3.8 GHz make greater demands on motherboards, with a TDP of up to 115 W.
Last year, Intel introduced the Performance Requirement Bit, to avoid problems caused by demanding processors. This flag basically helps to check whether the motherboard matches the high requirements of high end CPUs. If it does not, the processor will automatically fall back to a safe mode and run at only 2.8 GHz.
However, the dual core processor Smithfield will entail an even higher TDP; several documents we received talk about 130 W. The fastest dual-core model will run at 3.2 GHz. Due to these additional requirements, there is no option but to alter motherboard specifications. While doing so, Intel also changed the LGA775 specifications with the result that current motherboards will not support dual core processors.
Intel of course wants to spread the message that the upcoming 945 and 955 chipsets are required to operate a dual core processor. From a technical point of view, however, that would not be necessary if a motherboard maker decided to change their motherboard routings. This is particularly interesting as the new chipsets won't introduce as many new features as the 915/925 models did back in June last year. Yet obviously, the 945 will be more expensive than the 915.
The dual core difficulty might also be the reason why NVIDIA had to wait before introducing their Pentium 4 nForce chipset. Why would enthusiasts want a high-end motherboard with SLI that does not support the most interesting processors to come out in years? NVIDIA is likely to wait for a new chipset stepping in order to start their P4 business.