Samsung SSD magician over provisioning

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bgrego

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The Samsung Magician software includes a portion for over provisioning. It has a recommended setting which appears to be about 10%. My question is that it shows OP available as 0. I thought part of the SSD was already setup with a portion allocated for OP. So I am wondering if following its suggestion and letting it set up that recommended amount would actually improve performance or just basically shrink my drives volume. It is the Samsung 830 256 GB version.

Thanks in advance !
 
I am also a Samsung Evo 250Gb SSD owner and have a question (Sorry for high jacking). If I do this OP to 10% and I already have this drive as my master and already cloned and in use, Will it wipe all my data and will I have to do a fresh install of my os + apps or will it just allocate more space for the SSD and not change anything but make it a smaller SSD? Sorry for the noob question- kinda confused lol...
 


When I increased my OP on my 830 128, there was no problem. I believe this is because the SSD is constantly moving things around anyway, so it just takes the XS from what is not being used. Of course, YMMV.
 
I have the 840 EVO 120GB and my read/write went from 207/201 Mbps to 620/458 Mbps after enabling: high performance, RAPID Mode, OS Optimization and Over Provisioning. The biggest increase was after enabling OP (283/253 Mbps -> 620/458). All of this was done after enabling AHCI Mode in Win 7 and in the BIOS.
 


the set Op is about 10% that works out very well. do not try to get any crap online or you will corrupt the drive. Try setting it at 12% and you might get about 300 to 2000 ops on your random read/write speed but Samsung knows what they are doing with the drive. Go to the "Overprovisioning"settings and click on the custom then put it at what you want, then check your benchmarks. DO NOT CHANGE IT MUCH
 
If the Size is advertised as, lets say 128gb like mine, the real size is about 119gb. It the exakt same thing as with mechanical drives. Gigabit and gigabyte or whatever. Not because of OP. This is just as it always has been. Take the Advertised size, 128/1.074=119.2gb. So, if one wants to set up OP and the drive has no room set a side, does one need to shrink 10gb of the drive?
I am more interested in lifespan than speed in this case. My little poor SSD har written over 11TB of data and has lost something like 35-40% write speed. Want to keep it alive as long as possible. It still reads over 500mb/s witch is the important part for me.
 
I would use an exterior drive. Do you still have the drive that you replaced? Hopefully you hung onto it. Get an external housing for it and start saving all of your files, pics, music, and especially videos on it. This will free up the ssd and improve the read and write speeds. The other added benefit will be having a backup of all the files because most ssd's will start to crash or corrupt data when they are too slammed. If you don't have the drive look into getting a housing and a 7200rpm drive to put into it. For me this way has proven to be more convenient and also allows more functions to be completed in less time.
 
Pagefile is only 1.6gb (12gb of ram) and Hiberfile.sys is one of the first things I remove. =) Weird thing is that I had 55gb free but could only shrink 2gb so I did not do it. Want to free up 10gb. Putting the drive in a fresh APU build, dad´s 50th birthday tomorrow. Want to maximize the lifespan since it already have written A LOT of data. Still works really well and will kick the current mechanical disks ass. =)
 


This does not make sense. My 128GB Samsung 840 Pro shows 119.24GB usable in my OS. This is the 93% "1024" byte conversion that all drives are subject to. If what you say is true, then I should only have ~110.28GB of usable space. Where did you get this source of Samsung already "factory" over-provisioning SSD's?
 


Hi Brian, I am going to break down the mathematics for you. The previous user is correct in that Samsung already uses 7% of space for Overprovisioning. Here is how it works, but you have to understand the difference between GB and GiB, which I explain below.

Your drive STARTS with 128GiBs of space at the factory (this is 128GiB of memory based on powers of two, so 1024 Bytes = 1 KiB, 1024KiB = 1 MiByte, 1024MiB = 1GiB, and so on ). 7% off of that for the provisioning that is done in the factory. After that, you have:

128 * .93 (this is 7% off the total capacity that is done at the factory) = 119.04MiB

Which is roughly what you are seeing in your OS and is very close to the 119.24GiB that you mentioned. Note there is slight error in calculation, because every drive has a slightly different size (Even though the OS shows 119.24GB, it actually means 119.24GiB)

If you scale this number up to what you see on the box (128GB), you have to turn your GiB into B, and then into GB. Here is the calculation.

119.24GiB * 1024 ^3 (turns GiB into B (Bytes) = 128,032,975,093.76 B (bytes)

Now we will turn it into GB (powers of 1000, not 1024 as in GiB)

128,032,975,093.76 / 1000^3 = 128.03GB = Approx 128GB

The 128GB is what you see on the BOX when you buy it. So you can see that the unit still has 128GB, and still has the 7% over-provisioning still built into the drive.

the Samsung Magician software just allows you to add even more space to Over Provision than what was already setup at the factory.

Hope this helps.

 


I'm aware of the GiB to GB conversion. All drives are subject to the conversion, not just Samsung SSD's. I did a small amount of research and here's what the horse's mouth has to say about the situation:



Let's look at other drives, like my 1TB Hitache "deathstar" that's still running like a pro since 2008. My OS sees 931GiB of usable space. Quoting howtogeek,
To a hard disk manufacturer, one KB is 1000 bytes
Using the same 1024 conversion factor as above, we get:

1,000,000,000,000/(1024^3) = 931.32GiB.

From your post let's apply what you're saying to this HDD. Are you saying there's some part of 68.68GB that the OS is using on this HDD as "unallocated swap space" or some other over-provisioning "work bench" that the OS can use for garbage collection and trim support? Or, are these "extra/lost" GB simply due to the 1024 conversion process and this explains the discrepancy between what's advertised on the box and what the OS is seeing -- and these GB never existed as "unallocated swap space" in the first place?

When I over-provision the Samsung SSD to the recommended setting of 10%, am I actually over-provisioning it to 17%? 17% of what -- 128,000,000,000 bytes?

OR...a third option I just thought of and think you might have eluded to...did Samsung secretly put in ~9GB of extra nand cells strictly hard-coded for 7% over-provisioning -- and didn't advertise this extra space on the box? That would definitely explain this "factory" over-provisioning.

Does anyone else have input on this?
 
You know I'm starting to think this was my fault for bumping old threads with potentially out-of-date information. I tend to do this a lot and should force myself to not bump threads anymore.

AlbusDlx (earlier in this thread) noticed the same thing as me and his post was also recent from February. I bumped something JohnnyLucky said in 2012 and probably is true for drives previous to the 840 Pro. Apparently even the 840 "standard" drives are subject to mandatory OP so I would assume a lower reported total space would show up for those earlier drives. It looks to me like Samsung was confident enough to not force mandatory OP on the 840 Pro's because of the drive's ecc 3-bit nand cells and better overall quality (also hence a 5-year warranty.) I can only assume as well they were getting a lot of support tickets during that time asking about, "where's my drive space?!", especially on...say a 64 or 128GB drive where space is already limited and Magician not showing anything.

I'm sorry.
 



Researching OP on a 250GB Samsung 840 EVO SSD. After reading the posts by JohnnyLucky I've concluded that I'm going to doubt anything he has said until verified by my own research. He sites a lot of "checking", but provides no references to support his claims that go against conventional knowledge of how SSD's are provisioned.

rbs
 


@ryanbseattle,
When browsing the internet for software and hardware-related problems, there tends to be an overflow of guesswork, beliefs, subjective information, non-sourced information, and non-thorough information especially from users with high post counts and also from many users who've been awarded "expert" and "pro" badges. I've noticed a lot of mods who do this as well -- it seems to be an all-too-common knee-jerk reaction to simply post for the sake of posting, instead of actually providing information. Ironically, the "best answers" usually come from users with very low post counts -- someone who you can tell was so annoyed at the situation that he decided to take the effort of making a new account and talk about a specific problem at length and never visit the forum again once the problem is resolved. I'm not accusing Tom's Hardware of anything, I know and appreciate a lot of users are here, but the forum still is vulnerable to aggregate "groupthink" that makes resolving an issue difficult without a significant amount of time spent reading through noise. Take a look at my profile when I bumped a thread about Prime95 some time ago to see what exactly I'm talking about (this is when I first made my account here.) A lot of the time I wish companies like Samsung would hire English-major consultants who would make user manuals that describe many things with crystal-clear detail and explanations, but I know that's just a dream I occasionally laugh at.

Anandtech says the 840 EVO has default OP while CNET says it doesn't. Out of curiosity, what does the OP section in your Magician say? 250GB "manufacturer" should be 232.83GiB "OS" and then theoretically 7% of "invisible default OP" taken off that should be 216.53GiB reportable total space available to the OS. I would say that if you see 232.83GiB in multiple places then go ahead and do the recommended amount of OP in the OP section of Magician.

I went on youtube and found a British kid install his 120GB EVO, with his reportable space on the drive (don't ask me how long I finally found something specific like this) and heard that it was 111GiB (versus a calculated 103.94GiB if default OP was in effect) so my "educated guess" is that Samsung has decided against default OP on this drive as well. The British have never failed me at their skill of being thorough, now I know why MI6 rivals anything else the world has to offer :)

10/10, would analyze again.
 
All SSDs have factory reserved space. This factory reserved space is NOT available to the user and can NOT be changed. It does NOT show in Samsung Magician. This reserved space is needed for wear leveling and such.

Over-provisioning is used to increase the spare area and is in addition to the factory reserved space. Over-provisioning can increase the life expectancy of a drive (and sometimes performance also), but really is not needed unless you do a LOT of writing to the drive.

With most consumer SSDs the factory reserved space is about 7%.

Like RAM chips, most flash chips are made with capacities that are a power of 2 (although some new chips coming out may get away from this). So the actual total size of the drive (including the factory reserved space that is hidden from the user) will usually be a power of 1024 bytes. For example a 256GB SSD will actually have 256x1024x1024x1024 total bytes. But the user only has access to around 256x1000x1000x1000. The difference is used for factory reserved space.

Sandforce based drives are somewhat different. Sandforce based drives store the data on the drive compressed. Because of this they not only have factory reserved space for wear leveling, but additional factory reserved space for checksums. So a Sandforce 240GB drive will still have 256x1024x1024x1024 total bytes, but like 16x1024x1024x1024 bytes will be reserved for checksums, and then about 7% for wear leveling. This leaves around 240x1000x1000x1000 for the user.

In windows the size of a 256GB SSD will be reported as 256x(1000x1000x1000)/(1024x1024x1024) or around 238GiB.
240GB SSD will be 240x(1000x1000x100)/(1024x1024x1024) or around 223GiB.
 
Indeed there is a LOT of miss-information on over-provisioning. For example, ALL SSDs have factory reserved 'spare area' reserved for wear leveling and such. This factory reserved area is not available to the user and should NOT be referred to as over-provisioning. Yet is often is.

The factory reserved spare area has already been provisioned, over-provisioning is increasing the spare area beyond what has already been provisioned. That is why it has the 'over' in front.

I have a PC build guide magazine from MAXIMUMPC. In in it says that a 256GB SSD has no over-provisioning and a 240GB SSD has 16GB over-provisioning. This is just NOT accurate at all. Both have about 7% factory reserved spare area, but most 240GB drives have Sandforce controllers which have additional factory reserved area for checksums.

256GB will have like 274.88GB total (256x1024^3/1000^3), around 18.88GB system reserved and 256GB available to the user (windows will report this as around 238GB, but it is really 256GB or 238GiB).

240GB (Sandforce controller) will also have like 274.88GB total. Like 17-18GB system reserved for checksums and another 17-18GB system reserved for spare area. Leaving 240GB Available to the user (windows will report this as around 223.5GB, but it is really 240GB or 223.5GiB).

Windows has always used 1KB=1024 bytes, 1MB=1024KB or 1048576 bytes, and 1GB=1024MB or 1073741824 bytes.
This is not correct, as 1KB=1000 bytes, 1MB=1000KB, and 1GB=1000MB.
But the terms KiB, MiB, and GiB were not around when Microsoft started writing operating systems. So when windows reports KB, MB, or GB it really means KiB, MiB, and GiB.
 
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