Samsung To Ship Chip Package With Phase-Change Memory

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."

Electrical load limit?

[Anonymous Coward]

[QUOTE]But unlike NOR, PCM consumes more energy as it requires more write cycles, for which it requires more electric currents, Wong said.[/QUOTE]

I'm a new poster, so sorry I don't know how to quote.

Does the quoted bit mean that there is an upper limit on how fast you can write to the chip? Or is the total electrical current pulled for max protocol speed lower than the failure point of the chips? Will this generate excess heat? I'd imagine small chips would heat up fast too, since the writes would be more concentrated (lower memory bits to bits able to be written per second ratio.

cache for SSD?

[j1m+5n0w]

If PCM is faster but more expensive than traditional flash, it sounds like it might be useful to incorporate into SSDs as a cache, or alternatively as a separate partition to use as swap or to store the filesystem journal. Is there some reason why this wouldn't work (besides relative unavailability an expense at present)? Is PCM better able to deal with many erasure cycles (which is why SSDs aren't recommended for swap)?

Re:Performance?

[Anonymous Coward]

Pretend you're explaining this to an average person and then do that.

Okay. . .

Do you think it's going to rain Saturday?

People enjoy hanging out with me, because I know better than to bore people to death with irrelevant tech stuff, but since this is Slashdot, I'll pick a middle ground. . .

It's a lot like flash, but fast enough that it can be used to store programs and other things that aren't changed often, currently with flash those programs need to be copied to RAM before they are run, so replacing flash with PCM could allow you to get the same performance with less RAM. I don't think the difference is very significant, but if they can get the price down close to flash then it's worth doing anyway.

I'm guessing the effect on battery life would be pretty minor. None of these things use much power compared.

Re:cache for SSD?

[Anonymous Coward]

Actually, you forgot one step:

CPU Registers - CPU Cache, RAM - PCM - NAND Flash SSD - HDD - Cloud.

Every cache level has an associated level of cost - being able to pick & choose which layers you want & which data belongs in which layer is a powerful option for tuning performance (I would love to have PCM for my boot partition & executables - written rarely, read & execute in place means that you can have almost instantaneous boot times).