One more thing:
From a cost-perspective, DDR3L and DDR4 components are a lot cheaper "per Gigabit of Memory" than LPDDR4. Given todays market prices, LPDDR4 is almost twice as expensive than DDR3L or DDR4 for the same amount of memory.
But DDR3L and DDR4 components are only available in a x8 or x16 configuration, requiring to use multiple components to fill the bus-width of a rank. If you use a 32 bit wide bus, you would need to connect four pieces of x8 or two pieces of x16 components to each rank (with LPDDR4 you could just have one chip and you're done!).
Note: The i.MX8 supports maximum two ranks.
Both DDR4 and LPDDR4 are technologies which are limited to the worlds largest DRAM manufacturers. These big manufacturers require customers taking hundreds of millions of parts from them to fill their fab. Surely 99% or maybe more of the output of DDR4 and LPDDR4 goes into PC's, laptops, smartphones and tablets.
But now think about the following:
In latest a year all these applications will have changed to DDR5 and LPDDR5. The demand for DDR4 and LPDDR4 then might drop to only 1% of industrial customers. What do you think will the biggest manufacturers do? Will they continue making DDR4 and LPDDR4 ? I have doubts!
In the past, with all former memory technologies, smaller "fabless" DRAM makers jumped on the technology and produced compatible alternative parts. But the bad news is: This door is almost closed as the production of high-capacity DDR4 and LPDDR4 components requires production-technologies of 20nm or smaller, which cost BILLIONS of dollars. Only the largest memory-firms can afford that. Eventually the one or another fabless company will simply buy the parts from the big companies and marks them with their own part number, but once the large manufacturer goes EOL, the product from the smaller company will die as well, as it is the same chip.
You might only see some lower-density DDR4 and LPDDR4 from other fabless manufacturers which offer longevity. I know that Intelligent Memory has designed some DDR4 and LPDDR4 "with on-chip ECC error-correction" (which increases system-availability and reliability a lot!), but I do not yet see any other companies with plans for such parts.
While DDR3L technology sounds "outdated" to some people, it will be the technology that can securely survive long-term, simple because there are lots of manufacturers offering such parts and the demand for DDR3L does not depend on mass-market applications like computers, phones or tables.
Regards,
Thorsten Wronski
Memphis Electronic AG
We Know Memory
www.memphis.ag
