What is GDDR5 RAM – Works, Uses, Pros & Cons

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What is GDDR5 RAM? GDDR5 RAM is the short for Graphics Double Data Rate 5 Random Access Memory. This is a special type of Synchronous Graphics Random Access Memory or SGRAM.

This modern version of RAM comes with a high bandwidth. This actually doubles the data rate. This RAM is specially designed to use in:

  • The graphics card
  • Different gaming consoles and for
  • High performance computing.

Much similar to the GDDR4 RAM, the GDDR5 RAM is also based on the design of DDR3 SDRAM memory which is the double data rate in comparison to DDR2 SDRAM. The specific features of this RAM include:

  • It uses 8-bit wide prefetch buffers like those found in GDDR4 and DDR3 SDRAM
  • The standard of this SGRAM follows the standards set out in the GDDR5 specifications and
  • The GDDR5 interface that transfers two 32-bit wide data words per write clock, commonly known as the WCK cycle, to and from the I/O pins.

The corresponding 8-N prefetch used in its architecture is actually a single write and read access. It comes with a 256-bit wide dual CK clock cycle. This clock cycle can transfer the data in the internal memory core.

On the other hand, the 8 corresponding 32 bit wide one half WCK clock cycles can transfer the data and information to the I/O pins.

A single 32-bit GDDR5 chip consists of 67 signal pins, but, on the other hand, the others have the powers and grounds in a 170 BGA package.

The GDDR5 RAM functions with two types of clocks such as:

  • The CK, which is the Command Clock and refers to address and command inputs, just as the name suggests, and
  • The WCK or the write clock, which is a read and write data and has the ability to run at thrice the speed of the CK.

However, it can be stated that the GDDR5 SGRAM actually utilizes three clocks. There are two write clocks with two bytes namely the WCK 01 and WCK 23 and a single command clock or CK.

This means that, if the GDDR5 RAM is connected with a 5 Gbit per sec data per pin, the CK will run with 1.25 GHz and the WCK clocks will run at 2.5 GHz.

All these clocks are aligned in phases during the training sequence and initialization. This helps them to read and write easily and allows access with a bare minimum latency.

What is GDDR5 RAM?

What is GDDR5 RAM

The Graphics Double Data Rate Five or GDDR5 Synchronous Graphics Random Access Memory is the most useful RAM due to its high bandwidth, the double data rate and better structural design.

It is installed in the PCI slots and is designed to enhance the performance of the Graphics Processing Units or GPUs, all due to its innovative features. If you look into it closely you will see that:

  • There is an 8 N prefetch in it that enables the high-speed operating ability of this RAM.
  • This prefetch enhances the performance of the computer because the internal data bus is eight times wide.
  • There is an ultra-high bandwidth in the GDDR5 RAM that offers double data rate.
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Along with these features, this memory chip also comes with an adaptive interface timing. This specifically set timing ensures a couple of things for the computer system such as:

  • A more stable operating system
  • More data integrity of error detection and its correction
  • Higher performance at lower PCB or Printed Circuit Board cost and
  • Higher data eye optimization for high quality signals.

There are different generations of GDDR RAM and each of these have a specific numbering format according to the order of their release such as:

  • GDDR
  • GGGR2
  • GDDR3
  • GDDR4
  • GDDR5 and
  • GDDR6.

However, a GDDR memory chip is more expensive than a DDR but with a higher clock speed, larger bandwidth and with better power management capabilities than the DDR, this memory is worth spending a few dollars more.

GDDR memory chips are designed proficiently and typically to help in managing the graphics assignments that are produced by the Graphics Processing Unit or GPU. The primary job of the GDDR chip is to send and receive this data, which are produced in huge amounts, on the clock cycle.

Apart from that, the GDDR5 RAM is also considered one of the best because it has a very low latency. This high-end memory chip will provide a better performing ability to the graphics cards at a speed as high as 8 GB per second.

There is no need to be concerned with the power consumption even if you use it for a long time. This is due to its high bandwidth. This specific memory also has a better performance ability because it comes with a better I/O configuration of x16/x32. This draws power as little as 1.5 volts.

There are different capacities and sizes of GDDR5 RAM available in the market for you to choose according to your usage. These are:

  • 512 MB
  • 1 GB
  • 2 GB
  • 4 GB and
  • 8 GB.

The boost clock speed of the GDDR5 RAM is of 1545 MHz and the memory clock performance is found to be 14 Gbps. The 352-bit bus width of the memory chip increases the computing capacity up to 13.4 T flops.

Some of the best graphics cards available in the market currently, like the Nvidia GeForce cards, Gtx 1060 and Gtx 1070, all come with a GDDR5 RAM memory. Moreover, the high bandwidth of this memory chip helps the graphics card to double their speed and even increase the bandwidth of Gtx 1080.

All these features of the GDDR5 RAM helps in improving the performance, operating faster and better as compared to other graphics cards. The best part of this memory chip is that it is suitable in systems with the older technology.

It does not opt for stacked chips. Also, the shrinkage in the size of the graphics card from 28 nm to 16 nm helps in easy flow of electricity. This, once again, helps in increasing the performance but with low power consumption.

Since the time when the first RAM was introduced, different manufacturers were in the lookout to come up with better RAM with higher performance. Amongst and after several upgrades, these manufacturers came forward with the GDDR5 RAM.

This was first introduced in 2007. This memory chip had a 60 nm class 1 GB or 1024-bit specification. This supported 20 GB per second bandwidth on a 32-bit bus and had the configurations of 1GB at 160 GB per second with 8 circuits on a 256-bit bus.

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Next year, in 2008, manufacturers came up with the 50 nm class 1GB GDDR5 memory chip. This chip had more upgraded technology.

Therefore, it can be said that a GDDR memory is worth an upgrade due to its very high-performance ability, higher bandwidth, and a wider memory bus.

It can receive and request data both at the same time on the cycle clock and is designed in such a way that it reduces the consumption of power as well. It is also optimized for a reduced heat output.

Uses of GDDR5 RAM

As the years passed, the demand for a better performing and higher density memory chip was on the rise. The upgraded versions of GDDR5 RAM provided the users that desired support and allowed them to use it for different purposes. This included:

  • The large frame buffers of personal computers
  • High-end gaming that came with complex features and
  • 3D rendering and several other uses.

However, the rising demand for a better memory chip could not be met successfully till 2015 when mass production of 8GB or 8 x 1024 bits GDDR5 memory chips began. The design of this chip was based on a 20 nm fabrication process.

This chip successfully met the demands and even supported high resolution displays such as the 4K display. It was only then that this memory chip was extensively used and took to the mainstream. This higher density chip helped in facilitating larger frame buffers for graphical intensive consumption for computer gaming and other 3D applications and technologies.

How Does It Work

It is the higher bandwidth with increased high-density modules of the DDR5 RAM that helps it in its performance. Apart from that, the configurations of GDDR5 includes:

  • 8 Gbit per seconds per pin
  • 256 Gbit per seconds bandwidth per chip
  • x170 pins on the BGA package and
  • x32 bits per I/O cycle.

All these features of the memory chip helps the computer system to function at its optimum level. The GDDR5 memory chip works in the following steps:

  • The interface transfers two 32-bit wide data words per write clock or WCK cycle to and from the I/O pins
  • Then, the corresponding 8 N prefetch, which acts as the single write and read access having 256 bits wide two CK clock cycle data, transfers it to the internal memory core and
  • The 8 corresponding 32 bit wide one half WCK clock cycle data transfers it to the I/O pins.

The GDDR5 memory chip functions with two write clocks WCK01 and WCK23 with two bytes and one command clock.

The Pros

1. Higher bandwidth

The RAM comes with a higher bandwidth and a data rate of 4.8 to 6.4 Gbps. This enables it to perform at a much higher scale.

2. The prefetch buffer

The 8 N prefetch buffer is of larger size that gives it a very efficient and much higher memory bandwidth. Therefore, it can perform its functions much faster as compared to all the other memories or applications.

3. Power consumption

The memory chip consumes much low power, to the extent of 1.1 volts, but that does not affect its efficiency or stability. This results in reduced energy bills and longer battery life.

4. Higher clock rate

The RAM comes with a better and higher clock rate to the range of 1.6 to 3.2 GHz in the 4800 initial designs. This also affects its performance in a positive manner.

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5. Channel

It comes with a 40-bit channel that ensures high efficiency of the memory chip and lower latency.


The design of this memory chip consists of high capacity DIMMs to the range of 60 Gb, which, once again, adds to its performance level.

7. Interface timing

It has a far more adaptive interface timing as compared to other memory chips that annuls the need for trace length matching.

8. Integrity

You can rest assured of the integrity of the memory chip in data transfer due to its improvised transmission for the error detection and correction.

9. Cost

This memory chip is comparatively cheaper than other memory chips but with no compromise in its functionality, features and performance level.

The Cons

10. Capacity

The most significant downside of GDDR5 is its deficiency in capacity. This actually works point-to-point. This means that you will not be able to fit more than one chip for every 32/16 bits of memory bus.

11. Cost

The cost is much higher than a standard DDR RAM. Given the fact that it works only point-to-point, this RAM may prove to be a luxury for most average users.

12. Challenges

Though this has nothing to do with the users, the manufacturers faced a lot of challenges while designing it regarding the lower voltages and higher speeds that they had to deal with. This means that there could be a signal integrity issue if it is not perfectly balanced.

13. Compatibility

If you want to use a DDR5 RAM, you will need to find a compatible motherboard to install it. This will ensure that the DIMMs are able to handle the higher speeds of the signals transmitted by the system. This will in turn ensure signal integrity at all of the DRAM locations during simulation.

14. Signal reception

The signal reception of this memory chip will only be good if the Differential Feedback Equalization or DFE options are much more and far better.

15. Power delivery network

You must also ensure that the PDN or Power Delivery Network on the motherboard can handle the load, higher clock rate, and higher speed of data rates with clean and stable power supply. This will also ensure good signal integrity.

16. DIMM connectors

The DIMM or Dual In-Line Memory Module connectors of the motherboard must also be able to handle the data rates and clock speed for the RAM to function better. There should be reduced Electromagnetic Interference or EMI and better Electromagnetic Compatibility or EMC.


The latest version of DDR RAMs, the DDR5, is worth using if your system and your budget supports it. You should be able to enhance the performance, speed and power efficiency of your system significantly in that case.

About Taylor Swift

Taylor SwiftTaylor Swift, a UOPEOPLE graduate is a freelance technology writer with in-depth knowledge about computers. She loves to play video games and watch movies when she has no writing assignments. Follow Her at Linkedin