What is the difference between DDR5 and LPDDR5?

When shopping for a new laptop, you've probably come across a number of advertised specifications designed to sell you on the right machine. Making sure the processor (CPU), graphics card (GPU), and memory (RAM) have enough power to handle your desired tasks should always be high on your priority list, but the technical jargon isn't always easy to decipher. Looking specifically at RAM, modern laptops often have either LPDDR5 or DDR5 hardware. What's the difference, and which is better for your laptop?

RAM and its other acronyms

What is system memory?

The technology in PCs and other electronic devices is constantly changing, and it can be difficult for casual shoppers to keep up with the evolving acronyms and terms. And when it comes to RAM, you may come across many different names.

The general umbrella term for volatile memory is RAM, and most people casually refer to memory as “RAM” regardless of the underlying technology. However, if you delve into memory history, you'll probably also come across Dynamic RAM (DRAM) or Synchronous DRAM (SDRAM).

Memory module is an old technology that essentially took over the name SDRAM, and these days the terms are interchangeable. If your modern laptop has DRAM, you can be sure that it actually uses SDRAM. DRAM traditionally operated in an asynchronous mode, which meant that your CPU had to wait for the memory to catch up, causing performance issues.

SDRAM was a sort of evolution of DRAM that emerged several decades ago, and is now found in every modern laptop. SDRAM synchronizes with the clock cycle of the system CPU, resulting in faster performance and lower latency. Its design also allows for improved efficiency and reliability.

Conclusion? SDRAM and DRAM are now used interchangeably, but you can be sure that every modern laptop has SDRAM.

LPDDR5 vs DDR5 RAM

Ultimate performance or better efficiency?

DRAM is usually divided into Dual Data Rate (DDR) And Low Power Dual Data Rate (LPDDR) Categories. DDR RAM can be found in desktop PCs and powerful gaming or workstation laptops. LPDDR RAM, on the other hand, is often used in mobile devices such as phones and standard laptops where battery life and sleek design are more important than pure performance.

These are evolutions of LPDDR4 and DDR4 RAM, and DDR5 and LPDDR5 will one day be replaced by DDR6 and LPDDR6. Our guide to DDR4 and DDR5 RAM has a lot more information, but to understand the difference between LPDDR5 and DDR5 RAM, it's worth noting the key generational changes.

To recap, DDR5 DIMMs (Dual In-Line Memory Modules, or what you might call a “RAM stick”) are physically identical to DDR4 and have the same number of pins. Simply put, you can put a DDR5 DIMM into a motherboard made for a DDR4 DIMM. SODIMMor Small Outline DIMM, is a more compact version designed for installation in laptops.

More specifically, DDR5 DIMMs have two 32-bit channels, while DDR4 has only one 64-bit channel. The burst length has also been doubled from 8 bytes to 16 bytes to reduce latency. Memory modules have been increased from 16GB chips to 64GB chips, allowing more memory to fit in each RAM stick. In summary, DDR5 offers faster memory speed, higher chip density (for more memory per module), and lower voltage compared to DDR4.

Voltage is where the differences between DDR5 and LPDDR5 become apparent. DDR5 was introduced with an operating voltage of 1.1V, which is lower than DDR4's 1.2V. Of course, individual modules will run at higher voltages depending on overclocking and timing, but you get an idea of ​​the base efficiency.

When switching to LPDDR5, it operates with two voltage modes that scale based on the system's needs. Under load, it sees 1.05V and 0.5V for core and I/O operations, respectively, while at idle, the voltage drops to 0.9V and 0.3V for core and I/O operations, respectively. Due to architectural differences, LPDDR5 RAM can't quite offer the same high-end speeds as DDR5, but the improved efficiency is a reasonable compromise for devices that run primarily on battery power.

If you're looking to buy a thin and light device, you may also see LPDDR5x RAM listed. This standard is an offshoot of LPDDR5 and is designed to offer even better performance and efficiency. One final note is that LPDDR5 and LPDDR5x RAM are soldered directly onto the device's motherboard, meaning you can't upgrade it after you buy it.

Which is better for you?

I wouldn't recommend worrying about the differences between DDR5 and LPDDR5 RAM. Most people won't notice the difference in performance, especially as manufacturers push the limits of the current standard. You'll be much better off getting the appropriate amount of RAM for the tasks you want to do, while focusing on getting the right CPU and GPU.

DDR5 RAM is found in gaming or workstation laptops where performance is more important than longer battery life. LPDDR5 RAM is reserved for thin and light laptops where portability is a priority, which includes long battery life. LPDDR5 RAM is soldered onto the motherboard, so if you have DIY ambitions, I'd stick with DDR5 for a laptop with accessible internals.

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