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Interpreting SMART Data on Corsair SSDs


Yellowbeard
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In the last few weeks, I have spent quite a bit of time looking at the SMART data from a variety of Corsair SSDs. This thread is here to address the specific things I have observed about a few popular SMART reporting utilities, the SMART attributes and data, and the Corsair Force series SSDs.

 

I discovered some very interesting things about SMART monitoring and reporting. SMART as defined by the ATA standard is standardized. However, the structures or methods used by device manufacturers to report SMART attributes and status are not. Although there are some common standards observed across device manufacturers, there are many that are unique to each.

 

This problem is exacerbated by the fact that many SMART values have what is known as a raw value which is wholly determined by the device manufacturer. This raw value may or may not correctly correspond to a physical unit or normalized value, numbered 1-253. A great example of this is the recent issue of some SMART monitoring utilities reporting SSD temperatures of 156c or more! :flamethro

 

Additionally, there are a set of SMART attributes that only apply to SSDs. And, even within these SSD specific attributes, there are variations of the terminology used for these attributes. Finally, to completely complicate things, not all SSD controllers report the same SMART attributes.

 

Many SMART tools were originally only designed to monitor HDDs. Some current tools are adaptations of older SMART utilities that have been modified or updated to include SSD attributes. Unfortunately, due to the variations of SMART attribute reporting across the many different SSD controllers, it is almost impossible to find a tool that is accurate across all brands of controllers AND that also correctly deals with all the SSD specific SMART attributes.

 

We are working dilligently with SandForce and with the developers of some of the more popular SMART monitoring utilities to improve the accuracy when using these utilities with Corsair SandForce based SSDs. In the mean time, here are some screenshots of some of these issues that you may want to be aware of. In short, if your drive is performing within specification, then you should be skeptical of any SMART utility that is indicating issues.

 

Keep in mind that this is not a condemnation of each respective software developer or criticism of their efforts. However, we feel it is important to show our customers some examples of what is going on as we work our way through this situation.

 

An important item of note is the method of determining Health Status or SSD Life Left. Some SSD controllers report an attribute not seen on SandForce attributes, 205 (hex-D0). This attribute is the MAX Program/Erase cycles for the SSD. This attribute is used on some controllers combined with atttribute 5 (Reallocated Sector Count aka Retired Block Count) to determine SSD Life Left. Since this attribute is not reported by the SandForce controller, it is impossible to determine how the monitoring utilities are determining SSD Life Left or Health Status reports.

 

 

Crystaldisk 3.7.0

 

In this example, we can see 2 different temperature attributes reported. Obviously a working drive is not at 0C and there is no raw or normalized value given.

 

This report is also problematic as the second attribute, E7 (aka 231) is still reported by some tools as a drive temperature. Here it is showing SSD Life Left which is an SSD attribute. However, we have also verified that the SandForce controllers are not currently reporting the E7 attribute correctly. So, we believe that it is not a reliable reporting of SSD Life Left.

 

As you can see, this drive is new having been cycled only 12 times and been powered on for 3 total hours. I took it out of the box, installed Windows 7, and took these screenshots. It has never been benchmarked. With so little usage, and these reporting anomolies, we don't believe that 96% is an accurate estimate of Health Status for this drive.

 

attachment.php?attachmentid=7309&stc=1&d=1283407396

 

 

 

DiskCheckup

 

This utility, with a release date of August 19, 2010, shows several Unknown Attributes, some of which are circled in red. These attributes are reported by other tools including CrystalDisk. Therefore, it is unclear why this tool would not show known SMART attributes shown by other utilities.

 

We again see the E7/231 attribute reported incorrectly as a Temperature.

 

attachment.php?attachmentid=7310&stc=1&d=1283407632

 

 

 

HD Tune

 

The Health Warning indication for attribute 05 is an erroneous reading. We are looking into this and have not as of yet determined why this occurs. This same drive checked with the SandForce utility does not show any status indicating an issue.

 

Again, we also see the SSD Life Left attribute E7/231 reported as a temperature. As previously stated, this attribute has been determined to not be reported correctly by the SandForce controller.

 

 

attachment.php?attachmentid=7311&stc=1&d=1283408447

 

So what does all of this mean to end users? As stated above, we don't believe that the current SMART tools are completely accurate in their reporting. Our suggestion is to use performance as read by ATTO as a tool to determine if your drive is functioning properly. Remember, no SSD is going to report 100% life left, even fresh out of the box.

455786998_F40CrystalDisk2.jpg.5c6a731afb3e1f8e9ce1ea0d54fadb8c.jpg

474342325_F40DiskCheckup2.jpg.dc968f0c33ac354b833dcc43f9af898a.jpg

75213695_F40HDTune2.jpg.9b8614d6bad1fd903d926a9c13804417.jpg

Edited by Yellowbeard
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According to our Engineering people, the F40 and F80 drives do not have temperature sensors. So, any temp readings using those drives should be ignored. Also, readings on the other Force drives may still be incorrect with some utilities even after the 2.0 firmware update. Edited by Yellowbeard
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Hi,

I just "Secure eraser" my F60's with "Parted Magic" thats mostly recommended in here. Do ing it, i find that there is "Smart tool" too.

To my surprise i find that my mb's SMART was "Enabled" ( I was under, understanding that one of my options, make it disable, but no).

Ok, i didnt expect it, but it didnt muther because, it all so sayd "Self test, Passed", for all my SSD's.

 

Reason why i mention this is, that i dont think those records are correct in it and maybe you Yellowbeard, would like to look in it, too...

 

Sorry my bad english.

Cheers, Mummy

Edited by Mummy
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To go along with what YellowBeard has stated. I have a F-120 that is roughly into 3 weeks of use. I have HDTune Pro 4.6 on my system. I am showing the 05 as being a warning as well. What is wierd I find is that the E7 shows a temp of 86, but the temp reading at the top and what shows in my Taskbar is 98 and it does move around a bit. I do feel this reading is correct. Why it would show one temp in the SMART window and then show a different temp elsewere is a great example of what you are describing. I am very glad to read this as I was thinking that maybe my drive is defective.

 

YB, you stated that your Corsair Utility showed a different reading, what Utility does Corsair use?

 

Thanks for the info!

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  • 3 weeks later...
How come there is no Corsair Utility to monitor these drives?
I asked that in another thread. ;):

 

Would this status be accurate? I've only had this drive for a few months, I got it late in April and installed then as well. I loaded Windows 7 on it and have been using it ever since.

ssd-status.thumb.jpg.1c8e97b78b73dfb790bf09d40eda25f2.jpg

Edited by Wired
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I've decided to get rid of crystaldisk since it doesn't give hardcore, actual facts about SSDs. Now I just rely on ATTO to give me facts about my Nova (probably will start benchmarking once a week or twice a month or something like that.) I also tried using Everest and to my surprise, Everest doesn't even detect my SSD (BIOS and Windows detects it though.) So, it seems like the current S.M.A.R.T technology is complete rubbish when it comes to SSDs.
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I've decided to get rid of crystaldisk since it doesn't give hardcore, actual facts about SSDs. Now I just rely on ATTO to give me facts about my Nova (probably will start benchmarking once a week or twice a month or something like that.) I also tried using Everest and to my surprise, Everest doesn't even detect my SSD (BIOS and Windows detects it though.) So, it seems like the current S.M.A.R.T technology is complete rubbish when it comes to SSDs.

 

It's not the SMART technology itself. It's the lack of standardization in how it's reported combined with the utilities that are inaccurate. It's sort a chicken vs egg argument.

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Whoops, I actually kinda blazed through it and didn't pay too much attention to it (I think I may have A.D.D) :D: Anyways, I'm hoping that someone out there will get the S.M.A.R.T tech down to a tee since benchmarking with ATTO does require you to write to your SSD.

 

 

SMART has nothing to do with writing to the SSD, so I have no idea what you're talking about.

 

Currently, the suggested method to manually assess SSD health and performance is to run ATTO. However, repeated benchmarking fills up the drive so it is not desirable to bench excessively as this in itself will lead to performance degradation. I think what he means here is that it would be great if you could interpret this type of information correctly with an SSD tool as opposed to having to bench it. However, health status and performance are 2 very different things so even a properly functioning SMART utility will not tell you everything you may want to know.

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Yeah, sorry for the weird posts. I was very tired yesterday and couldn't get myself functioning correctly. Anyways, I've been meaning to ask someone; I believe the read/write speeds on the Nova 32gb are 195MB & 70MB respectively. However, I've gotten around 210MB read & around 74MB write on ATTO (which was like 1.5 weeks back) and was wondering why I've gotten higher speeds than stated on the box (not that I'm complaining :D:) Again, I'm a newb at the whole SSD thing and I'm trying to get as much knowledge as I can about these things (love this SSD too much!)
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  • 1 month later...
  • Corsair Employees
The published specifications are an average and it can vary from one system configuration to another, just because any ones benchmark is 10-15% low or high is no reason to be alarmed, not to mention if its the BOOT drive you are testing the O.S. will use some of the drive bandwidth/Performance for O.S. over head. So in short your drive is performing fine in fact better than spec. and I would not worry.
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I have just installed Fedora 14 on my brand new Force 120 and the disk utility (2.30.1) reports that SMART indicates 832 bad sectors (5 - Reallocated Sectors).

 

Is there a way to confirm the health of my disk on Linux? I am willing to install any (free) distro if necessary.

 

I am already having some crashes with firefox and I really need to know if this is because of the disk or something else (cant imagine what though).

 

If there is no way of confirming this then I will have to return the disk as faulty.

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1. No, there is no way to reliably verify this with any utility that I am aware of at this time.

 

2. EVERY device that uses NAND flash is going to show bad sectors. It's the nature of NAND flash to have sectors that do not work. This is true with SSDs, USB FDDs, cell phones, iPods, etc etc etc. So, if you do have bad sectors and this count is accurate, it's about 40KB of bad sectors from 120GB (unformatted value of course).

 

If your drive malfunctions, we'll gladly replace it. However, I would not suggest an RMA based on what you have posted here.

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So what does all of this mean to end users? As stated above, we don't believe that the current SMART tools are completely accurate in their reporting. Our suggestion is to use performance as read by ATTO as a tool to determine if your drive is functioning properly. Remember, no SSD is going to report 100% life left, even fresh out of the box.

 

See attachment

Untitled.thumb.jpg.4ca8fdfed5f0c3c9c302f94527855380.jpg

Edited by Wired
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See attachment

[ATTACH]7655[/ATTACH]

 

This is not true, as the SSD life reporting is not enabled on the drive.

 

Correct me if I'm wrong, but there is no standard way to report life so any manufacturer can come up with their own algorithm to display it; I wouldn't be surprised if Force/Corsair just set the drive to read 100 health all the time so that people would stop getting worried and complaining. So far with 2.0 the health always reads 100%...

 

Regardless the fact that any manufacturer can design their own health reporting makes the measurement rather unreliable and not useful imo.

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Hi there,

 

I just bought a used Nova V64 and for no specific reason checked the smart values under parted magic 5.4 -- out of sheer curiosity, well knowing that SMART is not properly supported (or the other way round) on SSDs of any maker.

 

Still, would some of you tech guys mind having a look at my attached screenshot and tell me please if these values can be safely ignored or if they in fact really indicate any wear-out (I would not expect so, the drive has been used for just a month).

 

Before you say "didn't you reads the top posts" rest assured I am not asking because of high temperature values.

 

This disk is intended for a small groupware server (OS only), so I'd like to be on the safe side.

 

Thanks a lot.

 

*Edit* sorry wiping the columns... I cannot fully remember, but the one with the zeroes is "threshold" and right to it is "lifetime worst" If you are lost with the screenshot I can fix it up, just tell me

Screenshot.png.a511dcfdc0227a17d2ddee26b0c699b3.png

Edited by spokekiller
addendum
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