The Samsung 840/840 Pro SSD thread

[frankieboy]

...I'm curious about how much I data is written to my disk per day... Do you (or anyone else) know of a program that tracks and records information like that?

Not as easy as it could be, but Smartctl reports the total LBAs written. A bit of arithmetic would calculate the data per day. If you're interested, see my posts a couple pages back.

Write amplification in SSDs means that the amount of data written to disk is greater than what you and your OS initiate. The LBA number provided by Smartctl would be the total amount written, including by write amplification. I linked to information on write amplification in an earlier post in this thread.

Personally, I don't worry about exhausting any current-generation SSD's write capability in a workstation-class environment. Andantech.com has covered this concern and done the math, conclusion being that anything but very extraordinary use scenarios are not a concern, even for the TLC NAND in the 840 non-pro. You can head over there and read the 840 non-pro review for yourself, if you want more information, and I recommend you do.

 

[S.B.G]

I've already gone for a Samsung 840 (just waiting for it to be delivered), but I'm curious about how much I data is written to my disk per day. I'm pretty sure that I don't do 10 GB per day on average, and can modify some habits and activities to utilize my external HDDs instead, but I'd love to know. Do you (or anyone else) know of a program that tracks and records information like that? iStat Menus records read and write speeds per disk in real-time and logs them, but doesn't compile it beyond the rates, and it doesn't give a day-by-day breakdown.


Based on the benchmarks that I've seen the 840 is a little bit better than the 830 in raw performance. The only area where the 830 is superior is in write endurance, where it is similar to the 840 Pro due to MLC usage (vs. TLC on the 840).

I'm not sure of anything available (maybe there is, maybe there isn't) that would tally how much total writes there are in a given time period. But, I think, that one would have a good idea of what is written each day based on what you're doing. If you rip a video that's 2GB, and write a few documents and visit some web pages where the browser stores a cache, you know you've written a little over 2GB. As for general background and OS writes, I think, they are quite minimal. Most writes are likely generated by the user and not the system.

As noted above in the chart, you'd have to write 10GiB per day, everyday for at least 7 years on the 840 before there is a predictable chance of failure.

10GiB of data translates to 10.73741824GB of data.

 

[frankieboy]

If you rip a video that's 2GB, and write a few documents and visit some web pages where the browser stores a cache, you know you've written a little over 2GB.

That would be true for regular hard drives, but write amplification could easily mean a significant multiple of that is actually written to an SSD. For example, in their review of the 840, Anandtech.com uses 10x write amplification for calculation purposes. Albeit that is a conservative figure, but at 10x, that 2 GB in your example is actually 20 Gb written to disk.

It isn't possible for us to know exactly what the write amplification is going to be, because it varies continuously with several factors. You'd need to know the firmware algorithms and the exact state of the drive in order to predict write amplification for a specific write.

OTOH, the "LBA blocks written" as reported by Smartctl, multiplied by the block size, are a reliable measure of how much data is really written to disk.

 

[paul-n]

A Samsung 840 has 1000-1500 program erase cycles. Even only using 1000 cycles would end in a 3 year usage with filling drive every day with data. If you calculate with write amplification of 5 it should be around 25 GB per day, only for the small 120 GB.

 

[chmodme]

10.8.3 and TRIM

Seems to behave differently. Currently unable to re-enable TRIM support on my Sammy 840 Pro after the 10.8.3 update.

FYI.

Interested what others have seen?

chmodme

UPDATE: two reboots later, re-ran the python script, TRIM is enabled again.

 

[pprior]

Well I've got an aftermarket GPU (Nvidia 680) and it doesn't have boot screen. Apparently I can't update my samsung 840pro because the bootable cd never shows anything on my monitor.

They need a in-OS updater!

 

[S.B.G]

Well I've got an aftermarket GPU (Nvidia 680) and it doesn't have boot screen. Apparently I can't update my samsung 840pro because the bootable cd never shows anything on my monitor.

They need a in-OS updater!

Are you trying to update it from an external ODD?

 

[iArch]

Seems to behave differently. Currently unable to re-enable TRIM support on my Sammy 840 Pro after the 10.8.3 update.

FYI.

Interested what others have seen?

chmodme

UPDATE: two reboots later, re-ran the python script, TRIM is enabled again.

After the software update I ran Groth's enabler, rebooted once and trim was on (500 GB 840).

 

[chmodme]

After the software update I ran Groth's enabler, rebooted once and trim was on (500 GB 840).

Thanks. I had to reboot a second time and then TRIM is re-enabled.

chmodme

 

[S.B.G]

10.8.3 update. I've restarted twice and cold booted once and Groth's TRIM enabler won't turn on. 512GB 830.

 

[chmodme]

10.8.3 update. I've restarted twice and cold booted once and Groth's TRIM enabler won't turn on. 512GB 830.

Turn it off. Reboot. Turn it on. Should be OK. Needs the "off" for one cycle....or that is what mine needed.

 

[S.B.G]

Turn it off. Reboot. Turn it on. Should be OK. Needs the "off" for one cycle....or that is what mine needed.

That's what I did. Restarted. Restarted. Turned off. Turned on. Didn't work.

 

[Ledgem]

That's what I did. Restarted. Restarted. Turned off. Turned on. Didn't work.

I think he meant turning TRIM off (manually, if the program doesn't have an option for it), rebooting, then turning TRIM on. If not, it's what I would suggest, anyway. Worth a shot.

 

[S.B.G]

I think he meant turning TRIM off, rebooting, then turning TRIM on. If not, it's what I would suggest, anyway. Worth a shot.

It's already off; it just won't turn on.

 

[Ledgem]

It's already off; it just won't turn on.

Even though it's recognized as off, can you use a command in Terminal to set it off, then reboot, and then turn it on? That should "zero" it out, just in case it's in some halfway state from the OS update.

 

[S.B.G]

Even though it's recognized as off, can you use a command in Terminal to set it off, then reboot, and then turn it on? That should "zero" it out, just in case it's in some halfway state from the OS update.

Do you know the command to share so that I may try it?

 

[Ledgem]

Do you know the command to share so that I may try it?

From this guide:

If you want to disable TRIM or completely reverse any changes performed with this guide, two options are available.

The first reverses the changes.

sudo perl -pi -e 's|(\x52\x6F\x74\x61\x74\x69\x6F\x6E\x61\x6C\x00).{9}(\x00\x51)|$1\x41\x50\x50\x4C\x45\x20\x53\x53\x44$2|sg' /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage

sudo kextcache -system-prelinked-kernel

sudo kextcache -system-caches

The second utilizes the backup file created and restores it over the modified one.

sudo cp /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage.original /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage

The backup assumes that a backup of the original file was made before TRIM was enabled. Chameleon SSD makes a backup, but I don't know if that's a standard operation of TRIM Enabler.

 

[S.B.G]

From this guide:

The backup assumes that a backup of the original file was made before TRIM was enabled. Chameleon SSD makes a backup, but I don't know if that's a standard operation of TRIM Enabler.

Neither one worked. I got this in return after the second line on the first method.

Kernel file /mach_kernel does not contain requested arch: i386

 

[chmodme]

Neither one worked. I got this in return after the second line on the first method.

Kernel file /mach_kernel does not contain requested arch: i386

That is a known "ignore this error" issue as your binary does not include i386.

You should be fine, reboot, and check it out. That error is benign.

 

[pprior]

Are you trying to update it from an external ODD?

I downloaded the disk image, burned it to a cd using disk utility and then rebooted holding "d" while booting - went to blank screen and stuck there. Internal Cd drive

I was never able to select the CD as a boot disk in disk startup

 

[S.B.G]

That is a known "ignore this error" issue as your binary does not include i386.

You should be fine, reboot, and check it out. That error is benign.

I've rebooted and shutdown and started up a couple of times since and still nothing.

I downloaded the disk image, burned it to a cd using disk utility and then rebooted holding "d" while booting - went to blank screen and stuck there. Internal Cd drive

I was never able to select the CD as a boot disk in disk startup

While rebooting, hold down 'Option' instead of 'D' and choose to boot to CD.

 

[S.B.G]

Not sure what the deal is with Groth's TRIM Enbaler, but I downloaded Chameleon this morning and it was able to turn on TRIM the very first time. 10.8.3 must have broke something in relation to Groth's.

 

[chmodme]

Not sure what the deal is with Groth's TRIM Enbaler, but I downloaded Chameleon this morning and it was able to turn on TRIM the very first time. 10.8.3 must have broke something in relation to Groth's.

Good news.

 

[frankieboy]

I know nobody posts here without reading the thread first, so I hesitate to post the following, but maybe "somebody overlooked something", so here goes.

Well I've got an aftermarket GPU (Nvidia 680) and it doesn't have boot screen. Apparently I can't update my samsung 840pro because the bootable cd never shows anything on my monitor.

Earlier in this thread I posted about the same problem, Swiss-G posted the below, and I followed his advice, and it worked:

Just out of curiosity did you burn a CD or DVD.

I couldn't get a CD to work but put it down to faulty media. I burnt a DVD and hey presto.

Did you try that?

They need a in-OS updater!

Hellhammer says one is in the works:

...Samsung told me that a Mac version of Samsung SSD Magician should be coming early [2013].

You could just forget about updating firmware, if you are only one update behind. The latest firmware probably does not make any difference on Macs, per this post by Hellhammer:

The latest update just fixes a bug that prevented the SSD from doing idle garbage collection on some laptops. Basically, the SSD entered such a low power state that GC couldn't be done, which resulted in degraded performance in some cases. However, I don't think OS X even supports HIPM/DIPM ATA features that enable the lowest power states, so there is nothing to worry about.

Lastly, you can perform the update by installing Bootcamp and a free trial copy of Windows. This avoids any need to use Samsung's bootable (or not) thingie. Once you have Windows up, download their Magician software for Windows and update your firmware. Afterward, you can use the Bootcamp installer to erase the Windows partition and recover the space it used. This is the method I used and it worked fine.

I found a free 90-day trial of Windows 7 SP1 here:

http://www.softpedia.com/get/System/OS-Enhancements/Windows-7.shtml​

(I have not downloaded or tested the file linked above. Use at your own risk.)

If you go this route, note that Apple just released updated versions of their Bootcamp software. There are several different versions for different hardware/OS combinations. Its available here:

http://support.apple.com/downloads/​

 

[Ledgem]

Not sure what the deal is with Groth's TRIM Enbaler, but I downloaded Chameleon this morning and it was able to turn on TRIM the very first time. 10.8.3 must have broke something in relation to Groth's.

How strange - I just installed my Samsung 840 and transferred over all of my data, and then tried to switch on TRIM with Chameleon only to find that it didn't work. Go figure! I'll try again later, after I've done any firmware updates that need doing and once the system has settled down (mdworker and kernel task are going hard at the moment).