The Register heeft een aantal redenen bij elkaar geraapt waarom de i840 chipset (waar Rambus wel werkt) geen mainstream alternatief voor de i820 zal kunnen zijn (het gerucht dat Intel mogelijk een Lite versie van de i840 chipset gaat maken heeft The Register trouwens zelf de wereld in gebracht):
Further investigation reveals that there are several key system level trade-off between Cost, Performance and Reliability that allow 840 system to run, while 820 systems fail.1. Carmel platforms use a six layer motherboard. This adds cost but improves signal integrity -- one of Camino's problems.
2. OEMs may play it safe by using 600MHz RDRAM on 840 production platforms. This improves timing margins and reliability at the cost of performance. This trade-off has proven unacceptable for uniprocessor PCs running business apps.
Workstation and server buyers prefer ECC (requiring 18-bit RDRAM rather than 16-bit). ECC helps with the reliability issues, but at an additional 20-30 per cent premium over the already high cost of Rambus.
The 840's dual Rambus channels are interleaved, and reportedly cannot operate in single channel mode. Each channel has only 2 RIMM slots, which is good, but configuration options are limited. RIMMs must be installed in matched pairs. 2 RIMMs or 4 RIMMs - thats it. Not quite flexible enough for low cost systems. These 4 trade-offs are unacceptable for the mainstream PC market - but they are why the 840 works and the 820 does not. Catch-22?
Volgens The Register zouden de eerste versies van de Camino chipset helemaal van Rambus slots ontdaan worden, meer daarover lees je hier.