26 August 2016

Game Over

Courtesy of AnandTech:
This means a system with 256GB of DRAM and a 768GB Optane drive can essentially act like a system with '1TB' of DRAM space to fill with a database. The abstraction layer in the software/hypervisor is aimed at brokering the actual interface between DRAM and Optane, but it should be transparent to software. This would enable some database applications to move from 'partial DRAM and SSD scratch space' into a full 'DRAM' environment, making it easier for programming. Of course, the performance compared to an all-DRAM database is lower, but the point of this is to move databases out of the SSD/HDD environment by making the DRAM space larger.

So, what are we waiting for kiddies? 5NF is like falling off a log from now on. You can ignore the bitching in the comments, of course.


Roboprog said...

So, it is a safe summary that this is largely like a traditional swap partition (or whatever OS-de-jure calls the virtual memory overflow area), but, the expectation is that the OS/driver code will know that random access works VERY well and that this is NOT spinning rust and try to schedule as if extra space had those latency restrictions???

So if RAM (DRAM) is "L4", this becomes "L5" - random access with some kind of address bus hookup as opposed to a hard disk interface?

Robert Young said...

still not entirely clear, but my take on it is that mmap() will use all 'memory' as one level. likely there'll be some driver in the OS to put most-recently-used in DRAM. we'll see. there seemed to be consensus that XPoint isn't consumer desktop driven. yet.

Roboprog said...

I suppose it's also possible that memory chip makers will simply start grafting flash drive type chips onto the little cards they currently put DRAM (and some cache) on. At that point, it will get interesting seeing what ratios of DRAM and flash they start throwing together for various uses.

Robert Young said...

hybrid memory has been talked about for some time. Intel/Micron 3DXPoint (here: http://www.simmtester.com/page/news/shownews.asp?num=17984) was touted as 'universal memory', but it's still too much slower than DRAM. time will tell what happens.