Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×

Comment Re:bc trim is application- dependant. Their assump (Score 1) 66

To clarify, 100PB is a number I pulled out of thin air. On reflection, you would not expect your SSD to do 100PB of data; II simply meant that a number IS usually provided, and that those numbers have been validated by multiple parties as generally being ballpark accurate.

Comment Re:Did you TFA? (Score 1) 66

Honesty time: Didnt read the article, but to say that TRIM fixes write endurance problems is highly misleading.

TRIM does impact endurance in that it CAN reduce write amplification (I believe) which can reduce the lifetime of your SSD, but it does not really change the fact that erase cycles are REQUIRED in order to reuse a cell. Again, all TRIM really does is schedule when that erase occurs-- directly prior to when it is needed, or at some idle time. Apparently (according to Wikipedia) SSDs using their own internal garbage collection instead of TRIM could cause write amplification, which may be what the article is alluding to-- Micron is no longer doing that, thus increasing endurance.

Read up on TRIM here:
http://en.wikipedia.org/wiki/T...

Comment Re:Lifetime at 16nm? (Score 1) 66

Anandtech disagrees. Techreport. So, in fact, do huge numbers of user reports which suggest that SSDs really do last a long time.

Further, multiplying this problem manyfold, is that when an SSD fails, it tends to fail totally.

I have seen this happen, but its not due to endurance of the flash cells but on the quality of the firmware / controller. The actual cell failures apparently cause reallocations (according to techreport's tests, and to common sense). And you create an interesting dichotomy; what does it look like for an SSD or HDD or CPU or RAM to fail "not totally"? You get most of your bits back? All tech generally tends to fail catastrophically.

Comment Re:bc trim is application- dependant. Their assump (Score 3, Insightful) 66

Theres a lot of misconception here, so I'll try to address them.

Making assumptions about how often trim might be used for any given workload only obscures the actual write endurance.

TRIM has nothing to do with endurance. TRIM erases cells that are scheduled for erasure anyways; all TRIM does is try to time that erasure such that it occurs at a time that will not effect performance. What affects endurance is wear leveling, which is an entirely separate technique that does actually work. As capacity increases, wear-leveling ensures that the endurance of the drive as a total increases.

Much like a 100GB capacity tape that's marked as 200GB because dome data that the manufacturer chose compressed 2:1 before being sent to the tape drive. Your mpeg movies aren't going to compress, so you'll be able to put 100GB of movies on that 100GB tape. The 200GB number is pure marketing BS.

When tape manufacturers (or organizations, like the one behind LTO) cite a compression factor like 2:1, it is based on a standard body of data like the calgary corpus which includes both compressible and uncompressible data. This allows you to compare different technologies with different compression standards.

In the real world on LTO (which I assume you are referring to) I have seen compression factors ranging from ~1.5 to 2.5, so its not really accurate to call it marketing BS. They also always (as far as I have seen) mark the tapes something like "800GB/1600GB" with the subtext explaining that the smaller number is native, and that the entire thing is 2:1. Its not dishonest because the compression is part of the (well-defined) standard, and the native capacity is right next to the compressed capacity. Its also not the manufacturer doing this; those numbers are explicitly defined in the spec.

all if the companies use the same 2:1 bs factor,

Which begins to make sense when you realize that thats because LTO itself defines the compression factor of 2:1 based on calgary corpus.

There's no telling what assumptions Micron made about the use of trim

But, as we've established, TRIM has literally no effect on endurance, so its irrelevant what they might assume about it.

so there's no way to compare this drive's endurance to any other, or to estimate it's actual endurance for any real workload.

Not to be harsh, but there is if you actually took the time to understand the tech. They usually do provide endurance stats (ie, "100PB data endurance") and tests by Anandtech and others have often validated that as being realistic.

Comment Re: Lifetime at 16nm? (Score 1) 66

That has nothing to do with the native cell lifetime.

It does when capacity increases faster than durability decreases. This has been addressed many, many times at each process shrink. The net effect is generally that you're better off spending your money on the newer process SSDs, they will last longer per $ spent.

Comment Re:Because of capitalism. (Score 1) 85

When you say "cruising on empty", how do you explain the huge number of top-tier tech companies that are US based? Intel, Apple, Microsoft, Red Hat, Google, nVidia, AMD, Qualcom...

Dunno, I kind of think capitalism does quite fine at providing ideas. Let me know when everyone else catches up to Intel's current process tech, till then maybe we shouldnt write off capitalism as "cruising on empty".

Slashdot Top Deals

If you have a procedure with 10 parameters, you probably missed some.

Working...