[AnandTech] SK Hynix: Up to DDR5-8400 at 1.1 Volts
As we've already mentioned, SK Hynix already has DDR5-6400 in its sights which are built upon its second-generation 10nm class fabrication node. SK Hynix has now listed that it plans to develop up to DDR5-8400. Similar in methodology to its DDR5-6400 DRAM, DDR5-8400 requires much more forethought and application. What's interesting about SK Hynix's DDR5-8400 is the jump in memory banks, with DDR5-8400 using 32 banks, with 8 bank groups.
Not just content at increasing overall memory bandwidth and access performance over DDR4, the new DDR5 will run with an operating voltage of 1.1 V. This marks a 9% reduction in DDR4 operating voltage which is designed to make DDR5 more power-efficient, with SK Hynix reporting that it aims to reduce power consumption per bandwidth by over 20% over DDR4.
To improve performance and increase reliability in server scenarios, DDR4-8400 will use on-die ECC (Error Correction) and ECS (Error Check and Scrub) which is a milestone in the production of DDR5. This is expected to reduce overall cost reduction, with ECS recording any defects present and counts the error count to the host. This is designed to improve transparency with the aim of providing enhanced reliability and serviceability within a server system. Also integrated into the design of the DDR5-8400 DRAM is Decision Feedback Equalization (DFE), which is designed to eliminate reflective noise when running at high speeds. SK Hynix notes that this increases the speed per pin by a large amount.