Thread: DDR2 Vs DDR3 information

Do you know that: DDR-3, the third-generation of DDR SDRAM technology, makes improvements in bandwidth and power consumption over DDR-2. Improvements in DDR-3 can yield up to 40% power savings over DDR-2 at the same speed and 66% higher bandwidth over DDR-2. DDR-3 DIMMs use the same 240-pin connector as DDR2 DIMMs, but the notch key is in a different position. DDR-3 DIMMs can run at different speeds, often called frequencies. DDR-3 operates at data rates from 800Mb/s to 1600Mb/s. DDR3-1600 DIMMs will be available in 2010. To increase performance and reduce power consumption of DDR-3, several key enhancements have been made: # DDR-3 DIMMs operate at 1.5V, compared to 1.8V for DDR-2 DIMMs. The DDR- 3 specification anticipates future availability of low voltage DIMMs, which will operate at even lower voltages. #An 8-bit prefetch buffer stores more data before it is needed than the 4-bit buffer for DDR2. # Fly-by topology (for the commands, addresses, control signals, and clocks) improves signal integrity by reducing the number of stubs and their length. This feature requires the controller to support ”write leveling” on DDR-3 DIMMs. # A thermal sensor integrated on the DIMM module signals the chipset to throttle memory traffic to the DIMM if DIMM temperature exceeds a programmable critical trip point. DIMM types Two different DIMM types are : 1.Unbuffered memory (UDIMMs) 2. Registered memory (RDIMMs) Manufacturers of DDR-3 SDRAM DIMMs produce two types of DIMMs: 1. Unbuffered DIMMs (UDIMM)— UDIMMs represent the most basic type of memory module and offer lower latency and (relatively) low power consumption but are limited in capacity. Unbuffered DIMMs with ECC are identified with an E suffix in the manufacturer’s module name (example PC3-8500E). UDIMMs are applicable for systems with low DIMM counts and where low power is required and large memory capacities are not required. 2. Registered DIMMs (RDIMM)— RDIMMs offer larger capacities than UDIMMs and include address parity protection. Registered DIMMs are identified with an R suffix in the module manufacturer’s name (example PC3-8500R). I hope this be informative !!

ddr2,,,,,,

akrlot, thank you for your information but next time:
1. source your post. You could get banned for this

2. make it readable. If you just copy paste and do not look at the lay-out, this is exactly what you get

3. use some images (upld on public image hosting servers) to lighten up the text, and to draw the attention.


Let me illustrate this for you:

DDR3 Memory Technology



DDR-3, the third-generation of DDR SDRAM technology, makes improvements in bandwidth and power consumption over DDR-2. Improvements in DDR-3 can yield up to 40% power savings over DDR-2 at the same speed, and 66% higher bandwidth over DDR-2.

DDR-3 DIMMs use the same 240-pin connector as DDR2 DIMMs, but the notch key is in a different position.

DDR-3 DIMMs can run at different speeds, often called frequencies. DDR-3 operates at data rates from 800 Mbits/s to 1600 Mbits/s. DDR3-1600 DIMMs will be available in 2010


To increase performance and reduce power consumption of DDR-3, several key enhancements have been
made:

• DDR-3 DIMMs operate at 1.5V, compared to 1.8V for DDR-2 DIMMs. The DDR-3 specification anticipates future availability of Low Voltage DIMMs, which will operate at even lower voltages.
  
• An 8-bit prefetch buffer stores more data before it is needed than the 4-bit buffer for DDR2 does.
  
• Fly-by topology (for the commands, addresses, control signals, and clocks) improves signal integrity by reducing the number of stubs and their length. This feature requires the controller to support “write leveling” on DDR-3 DIMMs.
  
• A thermal sensor integrated on the DIMM module signals the chipset to throttle memory traffic to the DIMM if DIMM temperature exceeds a programmable critical trip point.

Unbuffered Memory (UDIMMs) and Registered Memory (RDIMMs)


Manufacturers of DDR-3 SDRAM DIMMs produce two types of DIMMs: Unbuffered DIMMs (UDIMM) and Registered DIMMs (RDIMM). UDIMMs represent the most basic type of memory module and offer lower latency and (relatively) low power consumption but are limited in capacity. Unbuffered DIMMs with ECC are identified with an E suffix in the manufacturer’s module name (example PC3-8500E). UDIMMs are applicable for systems
with low DIMM counts and where low power is required and large memory capacities are not required.

RDIMMs offer larger capacities than UDIMMs and include address parity protection. Registered DIMMs are identified with an R suffix in the module manufacturer’s name (example PC3-8500R)

source: ftp://ftp.hp.com/pub/c-products/serv...rvers-Rev1.pdf

thanks nehpets for your information, but the source information not from these location, i had the HP course pdf hard copy , I typed this info to get members benefit, any way thank you, next time I will post with images

wow, learned some really good stuff with this , thanks ;)

Very useful information. Thanks you a lot

thanks nehpets for your information

Awesome, thanks for the info. I'm building myself a new computer atm, glad I stuck with 1600.

learned a lot of good stuff Thanks All