DDR3 technology dissected

[Andreas G]

DDR3 is the third incarnation of the DDR technology. While DDR2 needed several years to replace DDR, or even catch up in performance, DDR3 was faster than its predecessor from the very start, even if it wasn't by much. DDR3 has continued to excel over DDR2, but it is still too expensive for most consumers. Alas, there is a common misconception that DDR3 just enables higher frequencies at lower voltages, but there is more to it. Below is a nice list of features and improvements found in the article posted by Benchmark Reviews;

Features:

• Now supports a system level flight time compensation
  
• Mirror-friendly DRAM pin out are now contained on-DIMM 
  
• CAS Write latency are now issued to each speed bin
  
• Asynchronous reset function is available for the first time in SDRAM
  
• I/O calibration engine monitors flight time and correction levels
  
• Automatic data bus line read and write calibration

Improvements:

• Higher bandwidth performance increase, up to 1600 MHz per spec
  
• DIMM-terminated 'fly-by' command bus
  
• Constructed with high-precision load line calibration resistors
  
• Performance increase at low power input
  
• Enhanced low power features conserve energy
  
• Improved thermal design now operates DIMM cooler

Excerpt from the article;

"To begin with, DDR3 RAM modules can conserve up to 32% of the energy used on system memory, while at the same time saving money on maintenance costs for facilities HVAC systems.  Next on this list is the data prefetch buffer; which has doubled from only 4 bits per cycle to a full 8 bits with each pass.  Then comes the new Fly-by topology that removes the mechanical limitations of physical line balancing by replacing it with an automatically controlled and calibrated signal time delay.  After that comes latencies which are lower in rate than the previous curve, and in some cases offer 50% better timings per MHz.  Finally, we have all of the extra perks."

A highly recommended read for those who want to know more about DDR3 and what it really brings beyond DDR2.

 :: DDR3 RAM: System Memory Technology Explained

[tbf]

Well it's ok article when we don't look at the time of publishing 11th May 2008, and author gives us something like these

"The reality of the matter is that DDR3 is actually a better memory in terms of latency timings, especially compared against DDR2. So now imagine how tight the timings will be once the now infantile manufacturing process evolves from 90 nm to 70 nm; these latency timings will only get better."

Maybe first prototypes of ddr3 chips were produced in 90nm (hardy but if they were produced two yrs ago), Elpida and Samsung last year gone on ~70nm fabrication. So this story is part of some marketing bullshit feed looking into gaining some enthusiastic drouling for this paid-off shadow marketing published on some infantile site.

There is nothing technologically accurate, and truth is that even 70nm chips that we have today won't break skies (1825MHz on cl9 ... that's good just for poor MCH on intel's platforms) maybe 50-40nm in a 2-3years from now might reach cl6 on 5ns (1600MHz) and be overclocked to 2400MHz cl9/10.

[Delph1]

You have a good point there, but I felt that it still stressed at least a couple of good points, but most of all showed that there is more to DDR3 than just higher frequencies.

//Andreas
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