Platform change is a true constant in PC hardware, and both Intel and AMD regularly shift gears and introduce a new processor, motherboard chipset, or other technology that radically changes the desktop landscape. A few weeks back, AMD introduced the Socket 939 architecture, which essentially pushed the 940-pin systems into obsolescence, and created a whole new processor line. Intel has been very consistent of late, and their Socket 478 has been around longer than most Intel platforms. Many will remember one of the most prolific platform changes, when Intel introduced their Socket 423 Pentium 4, with RDRAM memory and a whole new set of chipsets.
That platform introduction may have seemed hard to top, but we're hear to say that Intel has finally done it, and not only matched the Pentium 4 debut with a new CPU package and memory type, but also upgraded the video card interface. Intel's' new LGA775 platforms are the very definition of a total platform revolution, and include a new line of Socket 775 processors, dual-channel DDR2 memory, and PCI Express graphics, not to mention a transition to Serial ATA and a host of smaller enhancements.
Today Intel has announced several new processors, and also moved into their new strategy of using model numbers, and not core speed, as their processor naming convention. The Intel Prescott is the core of choice, and it has been introduced at speeds duplicating its Socket 478 lineup, along with a higher-end Pentium 4 560 (3.6 GHz) model. The others include the Pentium 4 550 (3.4 GHz), 540 (3.2 GHz), 530 (3.0 GHz) and 520 (2.8 GHz). Intel has also ported over the Pentium 4-3.4 GHz Extreme Edition to LGA775, and it serves as the high-end enthusiast choice for the new platform.
The base architecture has not changed in the transition to LGA775, and the Prescott models still feature 1-MB of L2 cache, while the 3.4 GHz Extreme Edition is a Northwood variant with an extra 2-MB of L3 cache. What has changed is the CPU package, and it has shifted to LGA (Land Grid Array), which rotates the pin-out relationship between the processor and the socket. The underside of the new LGA775 processors has no pins, and only slightly raised contacts. The CPU socket features the required pins, and the CPU is inserted, covered, and then latched into place.
Land Grid Array devices are commonly used when high pin counts are required and the design needs a small form factor. These are very real concerns in the area of processors, and LGA775 delivers, but there is a potential downside to going the LGA route. These LGA processors require a holding mechanism to keep them in place, to assure proper contact, but this does bring up durability concerns. The motherboard socket now needs to be treated with the care of a processor pin-out, and it also requires diligence to install and remove these LGA775 processors. We did not run into any problems at all, but the myriad Intel warnings on the installation instructions certainly kept us on our toes.
Along with the new processor and socket designs comes an update to the heatsink-fan as well. The obvious change in the LGA775 heatsink-fan format is the elimination of any holding mechanism or bracket. All that is required for attachment are the four motherboard holes surrounding the LGA775 socket. The Intel reference HSF simply clicked into place, and for removal, the four mounting pins were turned and opened, and the unit slipped right out. The only caveat is to be extremely careful when installing the HSF, as without a bracket for a guide, it needs to be manually lined up.
The lack of a mounting bracket is a real benefit as well, and allows more real estate around the LGA775 socket, while giving manufacturers the ability to really lay on the cooper and aluminum for a heavy-duty CPU cooler. The basic Intel model we used in testing is not a behemoth by any stretch, but it is larger than a Socket 478 model, and did help maintain core temperatures, even at 3.6 GHz. The reference heatsink is a bit larger than Socket 478 models and the fan speed is higher as well, but it should be interesting to see what 3rd-party cooler designs start coming down the pike.
Pentium 4 560 and 3.4 GHz EE LGA775 Processor Review