I just bought a 512MB stick of PC2700 ram from an as-yet unnamed online vendor. It was an OEM piece, no packaging, just wrapped in bubblewrap with a sticker on it saying "512MB PC2700 - Warranty void if removed". The problem is that the chips are all NANYA nt5ds32m8at-7k, or 7ns memory. I'm pretty sure you can't get PC2700 out of 7ns parts, but I'd like some confirmation of my analysis before I start accusing the vendor of fraud or getting the credit card company involved.
PC2700 implies 2.7Gb per second, over an 8-byte interface, so the clock must be 2700/8, or about 333MHz, which is why PC2700 is aka DDR333. Halve the clock to account for DDR, and you get a 166MHz bus. Convert the bus frequency to clock cycle time and you get 1/166 = 0.006, or 6ns; therefore you need 6ns parts to meet PC2700/DDR333. This is all at theoretical maximum sustained rates, so CAS/CL specs don't come into play.
I also searched on Google using the part number, and turned up many references to PC2100, but nothing about PC2700. I suspect that someone has "upgraded" their inventory of PC2100 parts to PC2700 with a new sticker.
Is there anything wrong with my math?
Dave
PC2700 implies 2.7Gb per second, over an 8-byte interface, so the clock must be 2700/8, or about 333MHz, which is why PC2700 is aka DDR333. Halve the clock to account for DDR, and you get a 166MHz bus. Convert the bus frequency to clock cycle time and you get 1/166 = 0.006, or 6ns; therefore you need 6ns parts to meet PC2700/DDR333. This is all at theoretical maximum sustained rates, so CAS/CL specs don't come into play.
I also searched on Google using the part number, and turned up many references to PC2100, but nothing about PC2700. I suspect that someone has "upgraded" their inventory of PC2100 parts to PC2700 with a new sticker.
Is there anything wrong with my math?
Dave
