DDR5 vs DDR4: All You Need to Know
Here, we will examine the new DDR5 RAM specification, its features, and how it improves upon its predecessor. We will discuss what we already know about it and what we expect from it going forward. So without further ado, let’s dive into the new technology and see if all the hype surrounding DDR5 over the past couple of years was worth it. We will also examine if it will be worth the upgrade over DDR4 once DDR5 modules start hitting the market in the coming months.
What is DDR5 SDRAM?
DDR5 is the next generation of SDRAM that was announced last year as an upgrade over the DDR4 standard. It brings a number of new features to the table, including Decision Feedback Equalization (DFE), which enables I/O speed scalability for higher bandwidth and performance improvement. DDR5 promises improvements over DDR4 in memory capacity, speed and power efficiency, all of which are likely to be of massive help to gamers and workstation users alike. SK Hynix DDR5 DRAM / Image Courtesy: SK Hynix
DDR5 vs DDR4: Difference Between DDR5 and DDR4 SDRAM
DDR5 brings a number of changes over DDR4, which was released back in 2014 and brought several upgrades over DDR3. The table below gives a glimpse of the most significant differences between DDR4 and DDR5 SDRAM. A detailed explainer follows.
DDR4 vs DDR5
1. Bandwidth
DDR5 supports stock data rates of 4800-6400 MT/s, up from 1600-3200 MT/s in DDR4. The clock frequencies also sees an increase, going from 800-1600MHz in DDR4 to 1600-3200MHz in the new standard. Do note that initial DDR5 chips will only support up to 4.8Gbps before ultimately scaling that up to 6400Gb/s.
2. Power Architecture
Another major change with DDR5 is power architecture. With DDR5, power management moves from the motherboard to the DIMM, thanks to a 12V power management chip (PMIC). According to Rambus, the change will enable “better granularity of system power loading” and, should also help with signal integrity and noise. The shrinking transistor sizes will also ensure that the new generation of DRAM will reduce the IO voltage from 1.2V to 1.1V. While it will aid power efficiency, it will also result in a smaller margin for noise immunity, something that chip designers will have to take cognizance of. While typically, lower operating voltage (VDD) equates to lower performance, that’s not going to happen with DDR5 because of other advancements.
3. On-Die ECC and Higher-Capacity DRAMs
DDR5 also brings improved error correction (ECC) over DDR4, which will be an important feature for servers. What’s more, DDR5 chips will have have this feature ‘on die’, thereby removing the memory controller overseeing this function from the CPU. Alongside error transparency mode, post-package repair, and read/write CRC modes, on-die ECC not only brings additional gains in processing power, but also paves the way for higher-capacity DRAMs, which should translate to higher-capacity DIMMs. While DDR4 DIMMs go up to 64GB, DDR5 DIMMs can potentially hit a whopping 256GB.
4. New DIMM Channel Architecture
DDR4 DIMMs have a single channel with 72-bit bus, including 64 data bits alongside eight ECC bits. DDR5 DIMMs, on the other hand, will have two channels, each 40-bits wide with 32 data bits with eight ECC bits. While the total data width hasn’t changed from DDR4, the new specification will improve memory access efficiency, thanks to the availability of two independent channels.
5. Memory Timings
As for memory timings in DDR5, there’s no specific information about that yet. However, it is expected to have about the same latency as DDR4. Technological advancements in accessing memory may offer some improvements over its predecessor going forward. Finally, DDR5 also brings a massive improvement in ‘prefetch’, which is the amount of data read in one pass. DDR5 has a prefetch buffer of 16n, which is twice as fast as that of DDR4.
6. Burst Length
The final major change in the DDR5 standard is burst length. While the burst chop and burst length are four and eight, respectively, in DDR4, they’ve been effectively doubled to eight and sixteen, respectively, in DDR5. This will allow a single burst to access up to 64 Bytes of data, bringing significant improvement in concurrency (single channel) and memory efficiency (dual channel).
Compatible Hardware
As was the case with earlier generations, DDR5 modules will not be compatible with any existing motherboards and processors, including AMD’s latest 5000 series CPUs and Intel’s new 11th-gen Core processors. That said, the latter’s 12th-gen (Alder Lake) Core chips, scheduled to be released later this year, is said to offer DDR5 compatibility. Meanwhile, unconfirmed reports suggest that AMD is prepping to release its Zen 4 CPUs with DDR5 compatibility in 2022. SK Hynix DDR5 DRAM / Image Courtesy: SK Hynix
What is LPDDR5?
Not to be confused with DDR5, LPDDR5, or low-power DDR5, is the fifth-generation of Low Power Double Data Rate technology that was originally released in early 2019. While standard SDRAM is used in desktop computers, LPDDR5 is used in mobile devices for their higher power efficiency. It also has specialized use-cases in cloud computing, autonomous cars, AR systems and more. LPDDR5 succeeds LPDDR4x and, consumes up to 30% less power than its predecessor while improving data transfer speed by up to 50%. Notable devices with LPDDR5 memory include the Galaxy S21-series, Galaxy Z Fold 2 5G, Xiaomi Mi 10 Pro, OnePlus 8 Pro and more.
What is GDDR5 / GDDR5X?
GDDR5 refers to a now-deprcated generation of SDRAM chips designed for computer graphics cards. It is based on DDR3 SDRAM and uses 8-bit prefetch buffers. It was first announced by Samsung in early 2007 and, was commercialized by a number of semiconductor manufacturers next year. The standard has since been superseded by GDDR5X, GDDR6 and GDDR6X SDRAM, the latest of which is only found in Nvidia graphics cards for now. Notable examples of GPUs with GDDR6X memory include the Geforce RTX 3080 and 3090.
Availability
The first DDR5 DRAM was launched by South Korean semi-conductor firm, SK Hynix, in October 2020. However, it is aimed at ‘Big Data, Artificial Intelligence, and Machine Learning’ rather than regular users, including gamers, designers, video editors and 3D modellers. The first set of commercial DDR5 RAM modules are likely to become available this year, starting with server DIMMs during the first half of the year. Widespread availability for desktop PCs is only expected in the latter half of 2021.
DDR4 vs DDR5: Is it Worth the Upgrade?
The first retail DDR5 DIMMs are still some way away. However, when they are available, they promise to usher in faster computing for all use-cases. If you desperately want DDR5 RAM in your next rig, you may need to wait several months before it becomes widely available. It might be even longer before it becomes economically feasible for general users. However, it will have substantial performance advantages over DDR3 and DDR4. That said, it will take a substantial investment to change your entire setup (including at least CPU and motherboard) to take advantage of the new technology. So unless you’re using an old system that badly needs an upgrade, you’re likely to get much more bang for your buck by just adding an extra set of RAM modules and a high-quality cooler (for better overclocking) in your existing DDR4 PC for now. You can, however, expect the game to change once the new hardware is available. Given the early indications, once should expect the newer setup to offer significant benefits for gamers and professional workstation users alike, but only time will tell if an immediate upgrade will be worth it. After all, the early DDR4 DIMMs turned out to be slower than their DDR3 counterparts; something that only changed after the manufacturers and chip designers fine-tuned their products following a massive uproar among users.
DDR5: The Memory Standard of the Future
While the benefits of DDR5 are exciting, it’s unlikely to be available for retail buyers any time soon. What’s more, it’s likely to be a while before it becomes the default standard in all gaming machines, CAD workstations and other computers. Until then, the good old DDR4 models will work just fine. So now that you know more about DDR5 RAM and the difference between DDR4 and DDR5 (DDR4 vs DDR5), save you hard-earned cash for next-year, when we expect to have newer, faster hardware from CPU-makers and motherboard manufacturers to take full advantage of the new DIMMs. Meanwhile, you can also check out our guides on how to fix high CPU usage in Windows 10 and how to keep your CPU temperature under check.
