Intel Corp. announced that it would update some of its Intel Pentium 4 500-series microprocessors. The chips will feature new revision that has lead-free packaging and adds certain new EM64T instructions.

Intel indicated that the G-1 step Intel Pentium 4 500 processors will be RoHS compliant, its integrated heat spreader (IHS) will be marked per JESD97 guidelines with e4 designation. In addition, Intel will enable LAHF/SAHF EM64T instructions on the chips. The manufacturer said that while no significant changes are expected in electrical and thermal specifications relative to the G-1 stepping compared to the currently shipping E-0 stepping, a new BIOS will be required and clients are recommended to complete a full qualification of the chip.

Intel said that only four models of processors – 521 (2.80GHz), 531 (3.00GHz), 541 (3.20GHz) and 551 (3.40GHz) – will face conversion of the stepping. This may point to that the company does not plan to produce higher-end models – 561 and 571 – for long.

Intel Pentium 4 500-series microprocessors E-1 step at up to 3.40GHz are equipped with 1MB of L2 cache, designed for LGA775 infrastructure with 800MHz processor system bus and have thermal design power of up to 84W.

Intel will provide first samples of G-1 processors on the 9^th of September, 2005. First commercial supplies will be conducted on October, 17, 2005.