SSD Write Endurance 25nm Vs 34nm

[mbreslin]

You guys are asking for trouble, SSDs are an immature technology. You better backup any data you want to save, they will surely fail any minute!

[MadHacker]

You guys are asking for trouble, SSDs are an immature technology. You better backup any data you want to save, they will surely fail any minute!

Yes SSDs can fail at any moment and become read only.
hmm I better back up my data to a DVD or something that is read only

[Computurd]

i would recommend many devices that have large spinning platters of metal and tons of moving parts. the more moving parts the better!

[groberts101]

if Ao1 wasn't able to restore the V2 with a secure erase then there are other issues at play there. I would do a secure erase and test it as secondary using a quick sequential test with AS SSD. Even a hammered state drive would never go much below 50% of original fresh write speeds as the on the fly recovery is sufficient enough to keep from dropping below that.

These controllers implement a lifetime throttle called a settled in state when the Durawrite mapping has fully formed(all nand written to at least once). A proper SE will wipe that map completely and allow fresh speeds immediately afterwards. If it doesn't?.. something else going on there.

The other thing that needs to be kept in mind about Sandforce is the need for some idle time as TRIM alone will not initiate recovery as other controllers would do. SF needs that low activity idle time for the controller to recover those trim marked blocks more efficiently.

Also consider that if a Sandforce drive is barraged with random data like that it can take quite some time to rotate data and work towards improving internal data consolidation to allow any future writes to even have the slightest chance at being written contiguiously(which the controller tries to do whenever possible/within wear leveling's requirements. IOW,.. I've seen many that become far too fragmented(well..even moreson that usual for SSD) and can suffer badly. Still never seen one drop much below 50% of fresh incompressible write speeds though, and something seems odd given that the drive didn't respond to the SE as expected. I'd be trying it on another machine as a freshly SE'd/quick formatted secondary drive and I would guess that would help paint a truer picture.

How was the SE done and with what tool?

[Ao1]

I ran secure erase a number of times from the OCZ toolbox. It made no difference at all, most likely because DuraClass is located on an inaccessible secure area of the drive along with SMART & the fw etc. If it was accessible you could just bypass DuraClass with a secure erase, which would defeat its objective.

Obviously the load I placed on the SSD was extreme and it seems that DuraClass reacted accordingly. How long it takes to deactivate I don't know. Unfortunately access is not provided to the 230 SMART attribute to confirm or otherwise if DuraClass is active.

There is no information available about how it works, other than it will slow down writes that threaten to wear out the NAND before a predetermined life span.

It would be easy enough to repeat what I experienced by just running Anvil's app for 7 days.

Currently I have left the V2 plugged in and idle. I will leave it that way for three months to see if DuraClass is then deactivated.

[johnw]

One thing I don't understand about Sandforce's throttling is how it determine how many years into the warranty the drive is. Does the SSD actually have a clock on board? If not, I guess it can only judge the passing of time by how many power-on hours it has had. In that case, the throttling could make a huge mistake for someone who only turned his drive on for 24 hours once a month, but ran Anvil's program for the entire 24 hours each month. After a few months, the drive would think it is only a few days old, but it has written so much that it would throttle the speed to try to extend its lifetime, even though what it has written is acceptable for several months of life.

[Anvil]

Writing 24/7 is pretty extreme and no idle time is given.
I've had a few moments where I wished I had made a small pause at the time when the files are deleted or one single 30min pause per day.

I did test a small pause on the Intel and it didn't make a difference so I didn't bother, should be mentioned in one of the early posts.

I've never had any of my SF drives drop below 60MB/s (the 60GB) and about 90MB/s for the LE's, the workload the 40GB's are given is beyond anything they could possibly encounter in real life, even as "enterprise" drives.

--
45.6TB Host writes
MWI 74

I might give it a day or so on an Intel setup just to see if that makes a difference, could be this weekend.

[Ao1]

I got curious. The drive has been sat idle for 5 days. No data on the drive, which was secure erased before being left to idle.

I ran AS SSD twice. Seems that throttling has been reduced, but it's still evident.

[Anvil]

One thing I don't understand about Sandforce's throttling is how it determine how many years into the warranty the drive is. Does the SSD actually have a clock on board? If not, I guess it can only judge the passing of time by how many power-on hours it has had.
...

That is one of the major things I'd like to know.

If there isn't such a internal clock, well, it would be a disaster imho and the drive would last "forever".

[Ao1]

I will start running Anvil's app again until it gets full throttled. I will then unplug it, leave it for 5 days and then run a couple of AS SSD benchmarks. That should give some indiction if it is power on time.

[Anvil]

Ao1

Based on your test, that period could be 7 days. (there is no saying that the limit is based on a daily rate, so an avg on 7 days is just as likely)

[johnw]

If there isn't such a internal clock, well, it would be a disaster imho and the drive would last "forever".

Thinking about this some more, if it had a clock it would need a power source, either a small lithium button battery, or possibly a capacitor. I'm pretty sure there is no battery on the board (based on many pictures I have seen), so it would have to be a capacitor. But even the best capacitors would have enough leakage that I doubt they could hold a charge for months. So my guess is that there is no clock on board the Sandforce SSDs.

If I'm right, then it must either be using power-on hours, or perhaps it makes an assumption, like 8 hours power-on = 1 day of life. Either way, it could get the throttling way wrong for non-standard usage, like the guy I mentioned who only powers his SSD on one day a month.

[bulanula]

Thinking about this some more, if it had a clock it would need a power source, either a small lithium button battery, or possibly a capacitor. I'm pretty sure there is no battery on the board (based on many pictures I have seen), so it would have to be a capacitor. But even the best capacitors would have enough leakage that I doubt they could hold a charge for months. So my guess is that there is no clock on board the Sandforce SSDs.

If I'm right, then it must either be using power-on hours, or perhaps it makes an assumption, like 8 hours power-on = 1 day of life. Either way, it could get the throttling way wrong for non-standard usage, like the guy I mentioned who only powers his SSD on one day a month.

There surely is no clock all right !

[One_Hertz]

60TB. 70%. The reallocated sector count went up to 4 from 2 overnight.

[RyderOCZ]

It is powered on time and if you secure erased it you erased any throttling due to lifetime.

[sergiu]

It would be interesting to see as a comparation a similar test but with HDDs. Let's say taking a few models with 640GB or higher plates, make a 40GB partition at the beginning then do the same job and watch how many bad sectors popup in time. We could compare the reliability of old vs new technology when it comes to real usage.

[Ao1]

It is powered on time and if you secure erased it you erased any throttling due to lifetime.

Hi Ryder,

I ran a secure erase from the OCZ toolbox 3 or 4 times and it did not clear the throttling.

In post #252 write speeds came back after a couple of hours idling, but within an hour the write speeds went back to a crawl.

Prior to that happening the drive chugged along nicely writing continuously for 7 days.

I have now been running Anvil's app for 5 hours and write speeds have remained stable and within the parameters of the 1st 7 days of running the app. I will continue to run the app to see what happens next.

Does the OCZ Toolbox secure erase do the same job as hdderase?

If you can erase the Duraclass lifetime throttling (by inducing even more wear with a secure erase) what purpose does it serve?

[Ao1]

It would be interesting to see as a comparation a similar test but with HDDs. Let's say taking a few models with 640GB or higher plates, make a 40GB partition at the beginning then do the same job and watch how many bad sectors popup in time. We could compare the reliability of old vs new technology when it comes to real usage.

I was thinking that as well.

[Anvil]

I was thinking that as well.

Your not alone

[RyderOCZ]

Did you shutdown the drive after the SE?

Yes, toolbox just issues the ATA secure erase command, which is the same as hdderase.

I will check with my cohorts, but I am fairly sure that SE should stop a lifetime throttle. Lifetime throttle is all about the number of writes over a period of time. Get them too high and it slows down to prolong the life.

[Ao1]

I tried rebooting a number of times and had to create a new partition after each secure erase, so it would certainly seem that the SE worked, but the drive remained throttled.

Let's see if I can reproduce it with another onslaught from Anvil's app.

[Ao1]

Been running now for 7 to 8 hours and no sign of a slow down yet.

Delta between most-worn and least-worn Flash blocks is now 13, otherwise no change.


EDIT. Spoke too soon. Write speeds dropped by half mid way through a loop and are now steadily decreasing.

[Ao1]

Down to 6MB/s on Anvil apps within 460GB of writes. AS SSD as below.

Clearly DuraClass stepped in much faster this time.

Now I try a flash and a reboot. Then I'll run an AS SSD Benchmark and will post the results in a bit.

[One_Hertz]

The reads do not look throttled this time around.

[Ao1]

The sequential write test started off running quite fast, but then slowed down after a few seconds.

It appears that a secure erase does not clear the throttling.

Now I will unplug the drive, leave it 5 days before trying another AS SSD benchmark run.