Samsung To Ship Chip Package With Phase-Change Memory 57
angry tapir writes "Samsung Electronics will ship a multichip package later this quarter for smartphones that will include phase-change memory (PCM), an emerging technology that could ultimately replace memory types like NOR flash. Samsung's announcement is significant because it marks the first PCM product to be available as part of a multichip package. PCM uses a glass-like material that can change from multiple states to crystalline forms as its atoms are rearranged."
Re:Performance? (Score:5, Informative)
Read Speed
Like RAM and NOR-type flash, the technology features fast random access times. This enables the execution of code directly from the memory, without an intermediate copy to RAM. The read latency of PCM is comparable to single bit per cell NOR flash, while the read bandwidth can match DRAM. In contrast, NAND flash suffers from long random access times on the order of 10s of microseconds that prevent direct code execution.
Write/erase speed
PCM is capable of achieving write speeds like NAND, but with lower latency and with no separate erase step required. NOR flash features moderate write speeds but long erase times. As with RAM, no separate erase step is required with PCM, but the write speed (bandwidth and latency) does not match the capability of RAM today. The capability of PCM is expected, however, however, to improve with each process generation as the PCM cell area decreases.
Re:Performance? (Score:3, Informative)
ok - it is going to have the same seek time as a CF card but the read speed of your normal RAM - the write speed will be faster than your CF but slower than your normal RAM
as for Battery life - zero fucking clue
Re:Performance? (Score:4, Informative)
Re:Electrical load limit? (Score:4, Informative)
Re:Performance? (Score:4, Informative)
yes, but NAND is sloooow compared to NOR for reads. NOR memory (and PCM) looks like a SRAM to your system, thus you can execute directly out of it. NAND is awkward in its structure, so you can not execute directly out of it, instead you must copy the contents of the flash device to RAM.
Practical implications? If your device uses NOR or PCM you can use less DRAM in your design, if you use NAND then you need to increase the amount of RAM, often by as much as the size of the NAND memory (for smaller designs, larger ones will page memory from NAND)
Re:cache for SSD? (Score:3, Informative)
over 2,000,000 writes for some SSDs.
Writes for the entire drive, but most SLC NAND flash chips have a lifetime of 100,000 write cycles per physical sector, and MLC only survives 10,000 write cycles per physical sector. And most flash memory is going to MLC because of the much higher density.