Write speed always drops on Vertex 2 SSD

Soldato
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So Ive been told after hrs of getting my head around it:eek:


I thought the write speed slow down was if you hammered the ssd with loads of writing, but I was wrong, as Ive secured erased(format) my ssd 3 times as the write speed kept dropping in about 3 weeks of secure erasing the ssd.

It was really bugging me at this point as I was scratching my head, why was the speed droping after every 3-4 weeks of starting a fresh.

So I went on the OCZ forum and said why does this keep happening. After meny posts later I kind of understand it. Basically After the ssd has written once to all af its chips or whatever ud call them, the write speed drops to about half, and duraclass now controls all writes and subsequent write. This is what causes the slowdown of the write speeds, and theres no way to stop this from happening or speeding the writes back up again, unless you secure erase it everytime the speed drops

But like this guy says on OCZ....... "you will see/feel the difference mostly only at benchmarks. To 85 percent you don't never reach a sequential write speed of more than 67MB/s at normal usage."

So for me once the write speed slows up,, compressible data is about 150mb/s and non compressible data is 67mb/s. But it varies from system to system.

I hope this makes sense to you guys as Im hopeless at explaining stuff:mad:
 
Yep........LTWT (LifeTime Write Throttle). Sets in when too much is written in a short period of time or after every nand cell has been written to once, which ever occurs first. Just installing an OS, a few programs, and running large bench tests on a new drive can trigger the LTWT. Thank you 25nm nand drives..........
 
You will always trigger the slow down of the write speed as windows is constantly writing bytes here and their. I trigger mine in 3-4 weeks of starting a fresh.

Isnt it slightly false advertising tho, saying writes upto 275mb/s, I mean yeah you can achieve that speed during the first few weeks but after that your lucky if you get 160mb/s?
 
I mean thats why I couldn't understand why my write speeds kept slowing up, as no one tells you that the write speed is going to slow down after all the cells has been written to. I prob wouldn't of bought the drive if I knew this from the beginning:eek::mad:
 
As I understand from another forum that is known problem with Vertex 2. On the other hand C300 performs much better in that aspect. As I understood Vertex 3 should perform better.
 
Maybe your usage patterns are weird - Vertex 2s are best used as basic OS drives. Mine is as fast as the day it was new (5 months ago) with no secure erases since that first install and only 3 incompressible benchmarks.
 
Maybe your usage patterns are weird - Vertex 2s are best used as basic OS drives. Mine is as fast as the day it was new (5 months ago) with no secure erases since that first install and only 3 incompressible benchmarks.

You wont notice the speed loss until you benchmark the write speed

Heres mine:

A fresh install and about a month later.........

image1fc.jpg
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As this guy says..........

The SSDs with a Sandforce Controller seems to have 3 states.

The first is the fast one, all not used nand Flash has been cleared with a Secure Erase and the controller is able to write directly to the flash. But this mode ends, if every flash was used one time. On your drive, it could it be around 90GB of written data. You see the high speed by yourself with a write speed of 134MB/s.

The second one happens, if the “most” Flash was used to save any data ones.
You could have deleted the data again but the cells seem not to be cleaned up through the garbage collection to the same clean state as after a secure erase. To save new data to the "used" flash cells, the controller have first to clean it up (delete it) and only after this step, it is able to write the new data to the Flash cells. Could be your 64MB/s write speed.
On a few thread discussed, that a very long idle time help the drive to clean up the Flash cells at this use case to the better clean up state like after a “secure erase”. I have never tested it.

The third state is a mode to save the lifetime of the SSD and it slow down all the write speed of processes, which could be a benchmark or any other have load. It prevent a few benchmark user to kill all the flash erase cycles on the first big benchmark

and..............

2nd state is simply called "settled in state" and the controller has initiated a throttle to save life as well. Just not as severe of a throttle as the 3rd state. It's not that the controller must clean before write as it is simply just throttled by the firmware of the controller.

And yes, once all nand is hit, the drive will settle. Speed will never rise above this and the drive is designed to operate in this manner. Also consider that this drive is one of the top rated performance drives regardless of this incompressible write speed slowdown.

So what you see,.. is already factored into those ratings for this drive. Just use it as intended and if slowdowns/lags occur.. add more idle time to let GC keep up with your writing activity. Streaming video is the worst due to size and data type which hits more nand at the physical level.
 
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This is a piccie of my 60GB Vertex 2E when I ran ATTO at the start of November last year...

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this is one I have just done now...

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between those times I have installed and removed stacks of things from my OS (Win 7x64). I have had my steam folder on and off and games on and off etc etc. Video encoding and decoding has been done using the drive many times. Installing SP 1 for Windows 7. I have not bothered, but kept meaning to, leave the machine logged off for GC to do its thing, ever.
The only thing that I have just done is to run Perfect Disk on the SSD drive (not to defrag but to consolidate the free space). This I did before I ran this benchmark.

So for me, considering my usage pattern etc, the drive seems to be holding up fine.
 
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Just went off on a quick Google with regards to consolidating free space on SSDs and found this which is made by Diskeeper. I never even knew such software existed :confused:
 
I really do wish that I had done a before and after benchmark when I ran Perfect Disk 11. It does show in its logs...

Number of Fragmented Files Before: 12215
Number of Fragmented Files After: 102
Number of Fragmented Directories: 541
Number of Excess Fragments: 31103
Number of Excess Fragments After: 229
Percent Fragmented Before: 9.4%
Percent Fragmented After: 0.1%

Recommend Defrag Only because of File Fragmentation is high

When it notices that the drive is an SSD it will not offer to defrag it but to consolidate the space. This I did.

Having done that in the past (this was the first time since November(ish) I have noticed that I maintain a consistently high benchmark result. Whether PD has an effect or it is just snake oil I'm not sure but there is a thread here you can read...

http://www.ocztechnologyforum.com/forum/showthread.php?78276-PERFECTDISK-AND-SSD-quot-S

..even though it is shown in that thread for our types of drives you should benchmark using ATTO, and not that often.!

Perfect Disk and SSD's...

http://www.raxco.com/support/kb/791
 
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I really do wish that I had done a before and after benchmark when I ran Perfect Disk 11. It does show in its logs...

Number of Fragmented Files Before: 12215
Number of Fragmented Files After: 102
Number of Fragmented Directories: 541
Number of Excess Fragments: 31103
Number of Excess Fragments After: 229
Percent Fragmented Before: 9.4%
Percent Fragmented After: 0.1%

Recommend Defrag Only because of File Fragmentation is high

When it notices that the drive is an SSD it will not offer to defrag it but to consolidate the space. This I did.

Having done that in the past (this was the first time since November(ish) I have noticed that I maintain a consistently high benchmark result. Whether PD has an effect or it is just snake oil I'm not sure but there is a thread here you can read...

http://www.ocztechnologyforum.com/forum/showthread.php?78276-PERFECTDISK-AND-SSD-quot-S

..even though it is shown in that thread for our types of drives you should benchmark using ATTO, and not that often.!

Perfect Disk and SSD's...

http://www.raxco.com/support/kb/791

Im running perfect disk now, how often do you run it?
 
Perhaps free space consolidation is a feature that Intel and OCZ etc could integrate into their Toolbox software in the future? Must be a reason why they haven't done so already mind :p
 
Ok, its done, I was kind of pooping myself while that was happening cos it looked like it was defraging in some areas, but I just run crystaldisk and everything is still performing ok. Guess we will just have to wait and see now and cross fingers and toes.

image2zal.jpg


image3mb.jpg


image1yf.jpg
 
I would have thought the file fragmentation would been still at 2% but its at 0% and the numbers before and after,,, So Im a bit worried there?:eek::(
 
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