DDR4 is the standard memory used by the majority of the world’s computers including PCs, servers, tablets, and smartphones. However, it’s not exactly optimized for smaller devices like smartphones, tablets, or lighter notebooks in terms of power efficiency. LPDDR (Low-Power Double Data Rate) was pioneered by companies manufacturing mobile devices to create an alternative – one that consumed less power by sacrificing some of the computing power and speed. It has 10 generations including 1, 1E, 2, 2E, 3, 3E, 4, 4X, 5, and 5X. The LPDDR4X variant was created by Samsung. It reduces voltage further over LPDDR4 to make the memory more power efficient, among other improvements.
According to Samsung, it uses 17% less power compared to LPDDR4 and 15% enhanced performance for faster multitasking. By all means, it’s a truly revolutionary step. The ones that follow it (5 and 5X) are limited to high-end and specialized devices.
Today, we’re going to talk about what makes LPDDR4X superior to older smartphone memories and better overall.
Main Benefits of LPDDR
DDR4 memory is the staple of the world. It’s what virtually everything runs on. Released back in 2014, it was only in 2020 that its successor, DDR5, was released. Still, the majority of RAMs in the world are using DDR4. It’s powerful, efficient, and fast. Except, when we talk about using it in smaller devices like light notebooks, tablets, and most importantly, modern smartphones.
That’s why LPDDR was created from the chassis of the original DDR SDRAM, where LP means low-power. It sacrifices some of the computing prowess and speed to offer memory that’s easier on the power use, making it significantly more power-efficient in smaller devices.
The notable differences between the first version of LPDDR vs. DDR were lower voltage (1.8 vs. 2.5V), deep power down mode, and smaller chips. Samsung and Micron pioneered this technology. The second version came in 2009 and since then, we have had a new generation every 2-3 years, with the LPDDR4 released in 2014 and the LPDDR4X in 2017.
Note that LPDDR standards are independent of DDR ones. For example, LPDDR5 was developed for phones before DDR5 was developed for computers.
LPDDR4X vs. DDR4 RAM: Key Differences
LPDDR4X is one of the most used smartphone RAM options for any manufacturer looking to design a more power-efficient device. It ups the memory array clock from LPDDR4 (266 vs. 200), increases the I/O bus clock frequency (2133 MHz from 1600 MHz), increases the data transfer rate (4267 MT/s from 3200 MT/s), and offers an even lower supply voltage of 0.6V apart from LPDDR4’s 1.1V and 1.8V.
But how does it compare to DDR4, the main type of memory used by larger machines like laptops, desktop PCs, and workstations?
Here’s a quick comparison:
• Memory clock speed (MHz): 200 to 400 for DDR4; 266 for LPDDR4X
• I/O bus clock speed (MHz): 800 to 1600 for DDR4; 2133 for LPDDR4X
• Data transfer rate: 1600 to 3200 for DDR4; 4267 for LPDDR4X
As you can see, the I/O bus clock speed and the data transfer rate are both higher in LPDDR4X devices compared to DDR4 computers. When you consider that a typical stick of DDR4 RAM inside a PC chassis operates at 1.2V and LPDDR4X offers 2133 MHz at just 0.6V, it’s truly mind-blowing how far electronics for smartphones have come.
LPDDR4X as a Game-Changer
Modern smartphone systems-on-chip (SoCs) have quite powerful CPU and GPU subsystems. These can output a wild amount of raw power, especially the newer processors such as the 6nm MediaTek Dimensity 6100+ chip with an Arm Mali-G57 MC2. Add to that a robust amount of RAM, such as 24GB of LPDDR4X and you have quite a powerhouse. This is a niche combination, but easy to find in smartphones designed for rugged use, like the Oukitel WP33 Pro.
At the heart of these powerful chips are LPDDR4X RAMs that make the process of switching between apps and running multiple apps at the same time a breeze.
This type of memory has changed the game entirely, making it possible for modern smartphones to beat desktop PCs on memory-intensive benchmarks. All in all, LPDDR4X chips offer a significant leap from previous LPDDR variants as well as from most DDR4 categories. And they do all this by having a lower energy footprint, which is simply amazing.
Devices using LPDDR4X can easily go on a deep power conservation mode that you can’t find on any other device. They can use this while the device is in sleep or low power mode of some kind to offer remarkable improvements in battery life when you’re running low.
But that’s just one aspect.
Traditionally, LPDDR memories (and particularly the SoCs with an LPDDR4X RAM module) offer big energy savings even during operations. So, they give the same level of snappy and ultra-responsive performance at a fraction of the energy cost. Any device utilizing the LPDDR4X module will be able to conserve the battery life of the device in a meaningful and efficient way, increasing the longevity of the battery. Combine that with a high-mAh battery and you have a beast that can go on for days on end.
A clock speed of 4267 MHz (higher than the standard LPDDR4 and DDR4 speed of 3200 MHz) is blazing fast when you’re doing memory-intensive tasks, and devices equipped with it never feel slow. If you have a sizeable RAM on the device, upward of 12GB for example, you can be future-proofed for at least the next few years – without once worrying about running out of usable RAM in the middle of some work.
All in all, LPDDR4X offers unprecedented gains over older LPDDR variants as well as DDR4 SDRAM used by PCs. The next generations of LPDDR build up on this, independent of the PC industry’s DDR5 RAMs that were a little late comparatively. More or less, the LPDDR5, LPDDR5X, and LPDDR5T variants are limited to specific use cases, high-end devices, and unique workloads and prototypes as of now, with the latest variant, the LPDDR5T, being released as recently as January 25, 2023. The Dimensity 9300 supports it. That’s the only chip that does at this time.