GDDR3 (Graphics Double Data Rate 3)

From Bauman National Library
This page was last modified on 16 December 2016, at 21:16.
GDDR3 SDRAM
GDDR3
Type Synchronous dynamic random-access memory (SDRAM)
Predecessor GDDR2 SDRAM
Successor GDDR4 SDRAM

GDDR3 (Graphics Double Data Rate 3) - in fact, it is the same computer memory, but adapted to serve the graphics card. The digital value after the abbreviations mean generation memory, the higher the number, the faster the video card can process data. In fact it is a special memory technology for graphics cards developed by ATI Technologies. It has almost the same core technology as of GDDR2, but has a higher effective rate.

GDDR3 video memory has been developed specifically for the graphics card. This memory generation had the same characteristics as that of DDR2, but with an improved design, the power consumption was reduced and increased heat dissipation. As a result, an opportunity to increase the operating frequency of the memory (900 MHz), respectively, to increase the overall performance. By virtue of the specific use of graphics memory, namely GPU connection and DRAM with the topography of the point-to-point, the formation of I / O GDDR3 tire technology is used with open-drain and tied to this specific implementation vnutrikristallnoy termination (on-die termination, ODT), in contrast of the push-pull bus at the standard DDR2, it can dramatically raise clock speeds and simplifies PCB layout. There is an option memory DDR3L (L is Low) with even lower voltage, 1.35 V, which is less than the traditional 10% DDR3. In 2012, it was reported output DDR3L-RS memory for smartphones DDR3 memory chips are produced exclusively in the BGA type packages. Minimum capacity DDR3 memory is 1 GB. Maximum capacity of modules - 16 GB. For SODIMM, the maximum capacity is 8 GB. Despite the use of controllers for matching impedance (impedance-matching controllers), GDDR3 has a simple design due to the use of direct connect architecture.[1]

Сommercial implementation

First DR3 has been installed on a modified NVIDIA GeForce FX 5700 Ultra, and then in the GeForce 6800 Ultra. Although the standard was developed by ATI engineers together with JEDEC, its the first time the company has used nVidia. ATI itself started to use this type of memory in a series Radeon X800. GDDR3 is also used in game consoles, the PlayStation 3 and Xbox 360.

Gddr3

Despite the fact that the first card in order to use technology developed by ATI was the GeForce FX NVIDIA's 5700 Ultra, where they replaced GDDR2 chips used up to this point, the next card is used GDDR3 was GeForce Nvidia 6800 Ultra, where she played a key role in maintaining reasonable power requirements compared to its predecessor cards based on GeForce 5950 Ultra. ATI began to use the memory on their cards Radeon X800. GDDR3 has been selected by Sony for the GPU PlayStation 3 game console, although it is also able to NVIDIA the GPU-based access to the system memory, which consists of XDR DRAM developed by Rambus Incorporated (This technology is sold by NVIDIA as TurboCache in graphic PC platform processors) . From Microsoft Xbox 360 comes with a 512 MB memory GDDR3, and this helps to use the memory as a standard system memory, not only the video memory. Nintendo's Wii also includes a memory GDDR3. [2]

Advantages of GDDR3

Strobe (pulse) signal of GDDR3 unlike GDDR2 is unidirectional and has a single-ended output (Uni Directional & Single-ended). This means that during a treatment separate pulse data reading and rewriting process is faster than it was with GDDR2. GDDR3 memory is different from the previous version of the architecture: in particular able to reduce interference to other systems that provide greater stability of the entire system at frequencies around 800 MHz. At GDDR3 provided as a hardware reset potential, which allows you to extract all the data from the memory and only then restart it.

  • GDDR3 has the ability to reset the hardware, allowing it to clear all data from the memory, and then start again.
  • Lower voltage requirements lead to a reduction in power consumption.
  • Higher Frequencies.
  • Easy to manufacture.
  • Low heat.
  • Easy synchronization (GPU, VRAM, PCI-E).
  • Very high marginal volumes.
  • Low price.
  • An impressive margin.
  • Low latency timings.

DDR3 Features

  • Prefetch 8 words for each treatment (Prefetch buffer)
  • Asynchronous reset function with a separate contact
  • Support readiness time compensation at the system level
  • Flip the pin, easy to assemble modules
  • Implementation of CAS Write Latency per cycle
  • Built-in termination data
  • Built-in input-output calibration (time monitoring and adjustment of levels of readiness)
  • Automatic calibration data

Manufacturers of memory chips

In 2012-2013, more than 10% of the market DDR3 memory chip supply deals with the following companies:

  • Samsung - 40%
  • Hynix - 24%
  • Elpida (in 2013 acquired by Micron Technology) - 12%
  • Micron - 12%

A small fraction of the Taiwanese also had Nanya (Elixir, Nanya Technology Corporation) and Winbond.

Differences from DDR2, GDDR4 SDRAM and GDDR5

Gddr5

Differences DDR2

Advantages over of DDR2

  • Large bandwidth (up to 19,200 MB / s)
  • Low power consumption.

Disadvantages of DDR2 compared with

  • Higher CAS-latency (offset by higher capacity)
  • More power
  • Less heat
  • The following performance (due to less working memory frequency).
  • The disadvantages are higher during the CAS-latency (3 to 6), the resulting delay in the same (or even higher) frequency is higher.

Differences from 'GDDR4 SDRAM

  • Lower energy consumption (almost 3 times less than that of GDDR3)
  • Increased operating frequencies (1.2 - 1.4 GHz), but it brought only a slight increase in performance.

In combination with the high price of this type of video I have not received wide popularity and was soon replaced with GDDR5.

Differences 'GDDR5'

  • Display the operating frequency up to 5 GHz.
  • When using a 256-bit interface, GDDR5 can transmit data at a speed of 120 GB / s.
  • If we talk about the benefits, we can note an increase in productivity doubled compared to the previous generation of memory, reducing energy consumption and reducing the overall size of the video memory chips.


References

Cite error: Invalid <references> tag; parameter "group" is allowed only.

Use <references />, or <references group="..." />
  1. Method and Apparatus for fine tuning a memory interface: [Electronic resource]:Us patent office / Date of the application: 30.11.2016. — Access mode: [1]
  2. GDDR3: [Electronic resource]: Specific SGRAM Functions / Date of the application: 30.11.2016. — Access mode: [2]