CORSAIR Blog – DDR4 memory has had a great run with our excellent kits like our DOMINATOR PLATINUM RGB, VENGEANCE RGB PRO SL, and VENGEANCE LPX offering high performance and outstanding looks. With that said, DDR5 memory is on the horizon, bringing with it some key improvements for your current and future computing needs.
What is DDR5?
Better, faster, and more efficient! DDR5 aims to raise the cap on memory speed and capacity in a big way, pushing bandwidth up to 51 GBps (for DDR5-6400 at the time of writing). And raising the theoretical capacity of a single stick of RAM up to a whopping 128GB!
Why Do We Need DDR5?
More bandwidth allows for more efficient use of the memory bus in systems with high core count CPUs while the denser capacities will allow your system to tackle even more at once which is great for streaming and content creation (just to name a few applications).
When is DDR5 Coming?
Soon™! The industry is hard at work on bringing the next generation of memory to a desktop near you and we’ve been in the memory game for a long time. We’re excited to share more about DDR5 in the coming months so keep an eye out for more details from our social channels! In the meantime, we’ve put together this primer to help get you up to speed on DDR5.
With DDR5, individual modules are split into two separate channels by design, allowing for shorter traces that contribute to less latency and higher speeds when it comes to communicating with individual memory ICs on a memory module. This also allows for what’s referred to as command/address mirroring since the signal from the CPU has to travel a shorter overall path to access specific banks of memory whereas in DDR4 a command/address signal had to travel through all banks of memory in a longer chain.
On DDR4, when a single bank of memory needed to be refreshed, the CPU had to wait for all banks of memory on a module to refresh before doing another read or write. With DDR5, we’ve got double the bank groups and when a bank needs to be refreshed only the same bank of each group is refreshed, allowing for the other memory bank groups to be accessed without the CPU having to wait.
Overall single access latency with DDR5 is relatively unchanged, while CAS Latency has increased, the overall latency of a top-tier DDR5 kit will be similar to previous generations of DRAM clocking in at 14-15ns thanks to the improvements we previously mentioned.
Reliability goes down as process technologies shrink, resulting in higher latency and looser timings overall at higher speeds. DDR5 features on-die ECC as part of its spec, helping to reduce errors and allow for memory ICs to operate at higher frequencies. To be clear, this doesn’t mean that mainstream DDR5 is using a full-fledged ECC implementation, there’ll still be unregistered modules for typical consumer applications and ECC modules for enterprise/research applications.
Source: CORSAIR Blog