48.927 TiB, 141 hours, sa177: 18/18/4140
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71 hours, 20,0572 TiB, Wear Leveling Count and Percentage of the rated lifetime used has gone from 92 to 89.
Avg speed for all 71 hours is roughly 82,2 MiB
Attachment 117161
172TB. 11%. Reallocated sectors still at 16.
Hi B.A.T, the M4 seems to be doing rather well so far. :)
MWI is close to the 320, but writes speeds are much faster. The capacity of the M4 is larger, so faster write speed could be expected, but it does not seem to be having a significant impact on wear. (Compared to John's Samsung that is).
SMART attribute 181 is interesting. Looking at the literature that John posted: "This attribute tracks the number of use data accesses (both reads & writes) where LBAs are not 4KB aligned or where size is not modulus 4KB, assuming logical block size = 512B."
That seems to confirm a suspicion I had that 4KB alignment only occurs where it is possible, but in real life applications there are many reasons why 4K alignment may not be achievable.
Hi John, whoa, you will be first past the post at the rate you are going.
It's grinding away like there is no tomorrow. Top speed hangs around 100 MiB/s and it shows no sign of slowing down. I wonder when we will see the first reallocated sector?
Updated charts :)
Raw data graphs
Writes vs. Wear:
Attachment 117165
MWI Exhaustion:
Attachment 117177
Host Writes So Far:
Attachment 117166
(bars with a border = testing stopped/completed)
Normalized data graphs
The SSDs are not all the same size, these charts normalize for 25GiB of onboard NAND.
Writes vs. Wear:
Attachment 117168
MWI Exhaustion:
Attachment 117179
Write-days data graphs
Not all SSDs write at the same speed, these charts factor out write speeds and look at endurance as a function of time.
Writes vs. Wear:
Attachment 117170
MWI Exhaustion:
Attachment 117171
So, m4's WA is really close to 1.0 or is it just showing that number 341 based on an assumed WA of 1.0?
64GiB of NAND * 341 P/E cycles = 21.313TiB of NAND writes.
Compared to 20.0572TiB of Host writes, it does look like a very nice and low WA.
21.313 / 20.057 = 1.063x WA, makes me think it isn't assuming a WA of 1.00x.
2379446943762 = 0x22A02170012
So that is 0x217 * 60,000 = 32,100,000 non-aligned sectors written
Which, at 512B per sector, comes to 0.0149 TiB.
0.0149 / 20.0572 = 0.0745%
Or about 1 in 1342 bytes written is not 4K aligned. I wonder where that ratio comes from. Is that the ratio of random bytes written to total bytes written by Anvil's app?
53.426 TiB, 153 hours, sa177: 11/11/4491
At this rate, the normalized 177 attribute should reach zero sometime after my next update, tonight.
By the way, at 53.426 TiB written, the Samsung 470 could write half its total available capacity, 32GB, every day for five years. So no matter what happens from here on out, I think the Samsung 470 has proven itself as having sufficient endurance to be able to tolerate most conceivable real usage scenarios.
I think the M4 uses 8K pages with 256 pages per block.
Looking at Anvil's test file sizes they are a lot of entries that are not divisible by 4.
The new gen drives have lower PE and larger erase blocks, yet they still outlast 34nm drives. :cool:
EDIT:
Assuming a sector is 8k/ 8,192 bytes
32,100,000 non aligned pages * 8,192 = 262,963,200,000/ ~0.47TiB/ ~245GiB
guys is there any recommondation yet? I plan to buy a new storage ssd. I am off for long reliability, I totally don't care about insane high sata 3 performance.
John I'm really curious to see what is going to happen to your Samsung. :D If the static data has not been rotated a sizable portion of NAND will only have been written to once. I can't imagine the SSD would allow that to happen. If the data is rotated does it occur in idle mode or as a background task parallel to host activity? Maybe there is a critical threshold that will force the static data to be relocated to extend life?
:up: For fast sequential xfers this SSD is great.
Get the Intel 320 if you need most mature and reliable ssd because it has good endurance as shown here and also reliable controller with power capacitors etc.
Once the PE cycles have expired will data retention then be monitored? (i.e. how long will it remain read only) Maybe check the data integrity every 24hours?
I'm actually a bit down on Intel and the 320 SSD recently. A bug has shown up in the Intel 320 SSDs. It is somewhat random, but seems to be related to power-cycling, perhaps unsafe power cycles, perhaps sleep or hibernation. As far as I can tell, on any given power cycle the bug is unlikely to appear (at least I haven't had it happen to me yet), but given enough power cycles (and perhaps some random unknown factors), the bug seems more likely to appear. The bug is that the SSD becomes mostly unresponsive to most ATA commands, and shows as having 8MB (not GB) capacity. It is called the "8MB bug".
It seems people have reported this to Intel in May, perhaps earlier. So Intel knows about it. But they haven't issued any statements or warnings about it, and have not recalled the drives nor have they issued updated firmware. Rumor is that a fix is forthcoming in about a month, but no official word even on that. So I used to think a great deal of Intel on reliability and customer support, but my opinion of them has gone down quite a bit after this. If Intel issues a fix soon, they will partially redeem themselves, but not completely, since I do not like the way they have handled the situation at all.
http://communities.intel.com/thread/22227?tstart=0
http://www.pcreview.co.uk/forums/do-...-t4035508.html
I have a 42GB static file on the SSD with a known MD5 sum, so I can check that whenever necessary (it takes a while to read and compute the MD5, though). Once Anvil's app can no longer write to the Samsung, if the data can still be read I will check the MD5 sum periodically. Theoretically, the data retention should be at least a year after rated P/E cycles are reached, so I doubt I will check it every day.
Also, Anvil is working on a new feature for his app that will copy a file to the SSD (every X loops of his app) then read it back and check the MD5 sum (then delete the file again). Maybe Anvil can give an ETA on that feature. I hope it is ready soon, or the Samsung 470 might wear out before the feature is ready!
That is not at all clear. It could be that the probability of the bug occurring is constant for each power cycle. So every time you power cycle the SSD, you may be risking the bug. Certainly there are people posting about the bug in the thread I linked who only power cycled a few times.
We also don't know what the return rates are for the 320s. Maybe in a few months we will see how prevalent this bug is. In the meantime, I do not like the way Intel has handled it. That I know for certain.
The random writes are always aligned so if there are any they would have to be caused by sequential writes.
Wrt writing, the files should always be aligned but there can be partial writes, one doesn't write 4KB just because the file is say 12bytes.
The 12byte file will still take a full cluster which normally is 4KB, in the end it is handled by the file system.
I'm working on that MD5 routine, should be ready within the next few days. (maybe tomorrow)
--
131.79TB Host writes
MWI 28
Still at 6 reallocated sectors.
I've had a long weekend :), meanwhile it's been working through the TB's, MB/s is down to 32.8MB/s on avg for ~44hours. (~4.94TiB)
Will let it run for another 12 hours just to see how the avg changes.
Power cycle for three hours?
They are lucky they didn't kill some of the other hardware or cause a permanent Windows crash.
How many blue screens did they get in that 3 hours and have to reimage Windows.
If they were simulating Hot swapping that is say 30 times a minute x 60 min. x 3 hours = 5400 hot swaps.
Way beyond abusive to me either way.
81 hours, 23,0089 TiB, Wear Leveling Count and Percentage of the rated lifetime used has gone from 89 to 87.
Avg speed for all 81 hours is roughly 82,7 MiB
Attachment 117200
The 8MB BAD CONTEXT bug is rare, I've actually been bitten by that on a G2, the issue can be googled.
(some were able to just secure erase the drive but mine had to be sent back, it was in this state when it arrived)
Anyways, Why would one wan't to power cycle for hours?
Wonder what would have happened to other SSDs if they were treated like this.
There is nothing abnormal about it. I see a perfect parallel between this thread and the power cycle issue reported above. In both cases, we are trying to induce failure quicker than the normal use of the drive will do.
I hope Intel does write endurance testing and continuous power recycling test in a lab 24x7. Both are needed to claim reliability and life expectancy. With super capacitor added in 320, if Intel didn't do this power recycling test during QA in house, they made a huge mistake!
One more thing: Intel is lucky that it only takes 2-3 hours to reproduce the power issue. Intermittent issues are bane of the software world! Hard to reproduce and very difficult to fix! Any developer will tell you how frustrated they feel with intermittent issues!