
Intel’s Xpoint is broken - AnbeSivam
http://semiaccurate.com/2016/09/12/intels-xpoint-pretty-much-broken/
======
AnbeSivam
From the article -

> They claimed 10x the density of DRAM, it is now 4x

> Latency missed by 100x, yes one hundred times, on their claim of 1000x
> faster, 10x is now promised

> More troubling is endurance, probably the main selling point of this
> technology over NAND. Again the claim was a 1000x improvement, Intel
> delivered 1/333rd of that with 3x the endurance.

From this seminar few months back -
[https://www.youtube.com/watch?v=hXurTRtmfWc](https://www.youtube.com/watch?v=hXurTRtmfWc)
,

I think density can be increased, this is only the initial product,

and latency is contributed more by PCIe/OS/application rather than the
underlying 3d-xpoint material. The slides from the article are for the PCIe
SSDs, I wonder whether the earlier claimed latency, still holds well with
NVRAM.

I wonder why the endurance is so lower than the earlier claims.

~~~
hga
Ouch!

10x latency and 3x endurance might normally satisfy the "must be 10x better"
criteria to break into an existing market, but with the maturity of flash, and
how memory hierarchies can ameliorate useful sets of latency requirements,
this could end up being a damp squib instead of the revolution promised. 1000x
endurance would have been great, 3x, who will notice?

Not the first time Intel has grossly mismanaged its technology....

~~~
gpderetta
"memory hierarchies can ameliorate useful sets of latency requirement"

Not the latency for commits to stable non-volatile storage, unless battery
backed RAM is an option.

~~~
hga
Or just a big enough capacitor to finish the necessary writes to flash memory.
Which as I understand it is one of the things that distinguishes enterprise
from consumer flash drives, and one of the reasons I use the slowest, smallest
Intel enterprise flash drive for system and /home.

------
scriptproof
One should not confuse 3D XPoint that is a sort a memory and Optane that is a
product, a SDD. Octane uses all the traditional protocols to work like other
devices in a computer and that slow down the operations a lot. We saw the same
drawbacks with SDD when they used the SATA interface and the protocols of hard
drives, before special drivers improved their speed.

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audunw
How is it "broken"? I thought they meant that there's a fundamental flaw with
the tech, but instead it seems he just means that they didn't meet their
original goals of the tech with their first actual product.

~~~
imeron
SemiAccurate - the website this article is posted on - is a bit like the Daily
Mail of technology. It probably had clickbait titles before the word was
coined.

~~~
erichocean
perfectly named though—truth in advertising FTW!

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mankash666
The new numbers Intel is claiming, can be met by floating gate transistors
that are randomly accessible (versus those arranged in bit lines and word
lines like in NAND). Especially for a single level cell. No need for another
materials science/physics like "x point", unless"x point" actually is just a
PR spin without any new physics.

~~~
petra
Can you please explain this in layman's terms?

~~~
hatsunearu
Floating gate = the switching element on a transistor acts as a capacitor and
can hold charge. the basic primitive for building flash memory.

NAND SSDs which are common today are essentially rows of similar structures.
Each row is a string of floating gate transistors, and to read a single bit,
you gotta run the whole operation of reading the entire row.

Random access means that you can read anything anywhere without any sort of
similar caveats.

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icegreentea
Intel will probably end of spinning this as the first (more impressive) set of
numbers being estimates of the potential limits of the new technology.

Almost certainly those nice round numbers came from some engineers (or more
likely, engineering manager) being pressured for 'long term performance
estimates of the technology', coming up with something that seemed plausible,
and then wrapped up nicely into a marketing presentation.

Or, it might be that intel actually did have something approaching each of
those three claims - in three separate embodiments of the product, and is
running into problems combining the traits together.

In all cases, I feel for the Intel engineers working on this project right
now. Probably all cursing that original reveal.

------
themihai
So disappointing... I'm wondering if they did it intentionally to make room
for an upgrade(i.e like the TV industry did with 8K)

