RAM chips are organized as x4 bits or x8 bits. On a memory module you're just 
lining all these chips up in parallel so you have a 64bit wide data bus. All 
512MB modules are made using 16 pieces of either 64Mbit x4, or 32Mbit x8. If 
you use sixteen x8 chips you would get a 128bit data bus, so it has to be split 
into two separate banks. Each with 64bit bus. That's why 512MB modules 
based on x8 chips are dual bank. To build 256MB modules you can either use 
sixteen 32Mx4 chips, or eight 32Mx8 chips. But you can't build a 256MB 
module using 64Mx4 chips. To build 1GB modules you have to use thirty two 
64Mx4 chips. Two 64Mx4 chips are stacked on top of each other with a lead 
frame in between. Stacking basically converts two 64Mx4 chips into one 
128Mx4 chip or one 64Mx8 chip. Then you stick 16 stacks onto a PCB. 
Stacking also saves real estate, so you can fit more chips onto a shorter PCB 
and keep trace lengths in spec. 
If you are still unsure whether you are using x4 or x8 memory you can research the 
memory chip by the SDRAM part numbers, or go to 
search for jedec 21 c 4.20.4. 






 Home | About Us | Network | Services | Support | FAQ | Control Panel | Order Online | Sitemap | Contact

cheap hosting


Our partners: PHP: Hypertext Preprocessor Cheap Web Hosting JSP Web Hosting Ontario Web Hosting  Jsp Web Hosting

Cheapest Web Hosting Java Hosting Cheapest Hosting

Visionwebhosting.net Business web hosting division of Vision Web Hosting Inc.. All rights reserved