What about DDR4 VS DDR5?

DDR5 is the latest and most advanced memory standard, surpassing DDR4 in nearly all aspects. Both Intel and AMD’s latest CPUs support DDR5, marking a new era in the memory landscape. However, DDR4 remains relevant as Intel’s 12th and 13th generation CPUs, as well as AMD’s Ryzen 5000 series which offers good value for budget-conscious consumers, still support DDR4.

For users looking to purchase new or upgrade existing computer systems, choosing between DDR4 and DDR5 entails considering not just price and performance but also compatibility with their motherboard and CPU type.

What is DDR SDRAM? When people refer to RAM, they typically mean Synchronous Dynamic Random Access Memory (SDRAM). SDRAM synchronizes data transfer between the CPU and memory, acting as a “buffer” allowing the CPU to access and manipulate data quickly without continuously accessing slower hard drives.

DDR stands for Double Data Rate. Hence, DDR SDRAM means each clock cycle involves two transfers, an updated version based on the same DDR technology. This explains labels like DDR2, DDR3, DDR4, and DDR5, each generation progressively improving performance over its predecessor.

DDR5 Physically, DDR5 memory closely resembles DDR4. Unlike the transition from DDR3 to DDR4, which involved an increase in pins from 240 to 288, DDR5 retains the 288-pin layout of DDR4 but with slightly different notch positions.

The real differences lie in architectural design: DDR4 utilizes a single 64-bit channel, whereas DDR5 features two independent 32-bit channels (dual). Transfer length has also doubled from 8 bytes to 16 bytes.

Key Differences Between DDR4 and DDR5 Memory: Appearance and Interface Each new generation of DDR SDRAM offers more advanced features and better performance than the previous. They appear similar at a glance but have subtle differences. For instance, DDR4 is slightly thicker than DDR3. Additionally, the notch in the slot, which moved closer to the center during the DDR3 to DDR4 transition, remains slightly off-center in the DDR5 era but closer to the middle.

Initial Frequencies One of DDR5’s major advantages is higher frequencies. With the ongoing introduction and updates of multi-core processors, memory frequency upgrades are crucial. For example, Intel Core i9-13900K boasts 24 cores, and even relatively low-power Core i5-13400 features ten cores. In the future, mainstream PC markets will only provide powerful CPUs with more cores, so increasing memory frequency is highly important.

JEDEC (Joint Electronic Device Engineering Council) specifies DDR4 data rates (or frequencies) ranging from DDR4-1600 to DDR4-3200; for DDR5, the range starts from DDR5-3200 up to DDR5-6400. DDR5-4800 is expected to become the initial baseline, with standards continually increasing over time. DDR5’s higher frequency contributes to its superior bandwidth over DDR4.

Maximum Single Memory Capacity Another benefit of DDR5 is higher memory capacities. In the DDR4 era, maximum single module capacities reached 32GB. With mainstream motherboards supporting 2DPC (2 DIMMs per channel), the most common total memory capacity limit on DDR4 platforms was 128GB. In the DDR5 era, single module capacities have already reached a new level of up to 128GB. Comparatively, using the same 2DPC motherboard, total memory capacity can reach up to 512GB.

DDR5 Operating Voltage Power efficiency is also a highlight of DDR5 memory. At first glance, DDR5 operates at 1.1V, lower than DDR4’s 1.2V. However, some DDR4 memories can extend to 1.6V, indicating DDR5 could also increase voltage further. As market demand grows for faster memory speeds, DDR5 operating voltages may increase accordingly.

Notably, the motherboard does not handle DDR5 memory voltage regulation. New memories feature Power Management ICs (PMICs)—mainstream modules operate at 5V, while server-level operates at 12V. PMICs offer benefits such as improved voltage regulation, robust signals, and reduced electronic noise, yet they increase memory costs, a primary reason for DDR5’s current higher prices.

On-Die ECC On-Die Error Correction Code (ECC) is a new feature of DDR5 aimed at correcting bit errors within SDRAM chips. As SDRAM chips increase in density through smaller semiconductor process nodes, the risk of data leaks also rises. With On-Die ECC, DDR5 can mitigate these risks by repairing internal chip errors, thereby enhancing reliability and reducing defect rates.