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Possible Duplicate:
Does low disk space affect SSD performance?

Follow-up question: How do I calculate an over or under-provisioning amount of space for my SSD?

After looking at some relativly similar questions Does low disk space affect SSD performance and How much free space should I leave on an SSD?, I can not answer my question.

My question and related questions depending on the answers are:

Does an SSD require a certain amount or percentage of free memory to operate at SSD performance levels?

Is there a point where under provisioning is a required option to perform better than a 7200 RPM platter? If so, how do you calculate what is needed to be free so you can use each bit of space most effectively and efficiently before requiring an upgrade?

I use Windows 7 64, TRIM is supported on the drive.

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marked as duplicate by Dave M, Dennis, Graham Wager, Karan, KronoS Feb 4 '13 at 18:47

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

@DaveM - I have ref. that exact post in my question. It's result does not answer my question. Is it still a possible duplicate? Also, it is from 2010, more Knowledge and thoughts may have developed since then. – Carl B Feb 4 '13 at 17:59
@CarlB in this case I believe so. While the answers aren't of a great quality, the question is still pretty much the same. I would suggest placing a bounty on the duplicate and seeing if that gets the results you're looking for. – KronoS Feb 4 '13 at 18:47
@KronoS - thanks for your input. I will opt to post a new question that may be more specific or worded better, as indicated in the banner. – Carl B Feb 4 '13 at 18:58
that's fine and go ahead if you feel that is worth while. However, be careful of not "prettifying" the same duplicate issue. If you dress a duck as a swan, and the underlying issue is that it's a duck, the question will still be closed as a duck duplicate. Make sense? :P – KronoS Feb 4 '13 at 19:03
@KronoS - it does make sense. Maybe I will edit and plea for a reopening. I really do not see the elements of a duplicate, but that is my opinion and the community seems that it has mirrored the elements. So I will rethink my thoughts. – Carl B Feb 4 '13 at 19:12
up vote 3 down vote accepted

Well, according to the manufacturer of my SSD (Samsung), having a certain percentage of free space available at all times will improve the performance of data relocation operations, which the drive carries out internally. For this reason, the drive has an option to reserve some amount of space (hide from the system) for such purposes. This is what is called "overprovisioning".

As long as the drive has sufficient amount of free space, there's no need to reserve anything. The drive will use the regular free space to perform its internal operations. Overprovisioning is only needed to prevent the situations when the free space becomes limited.

It is certainly not required. The drive always have some (relatively small) amount of space unconditionally set aside to use as intermediate buffer for data moving operations. I.e. it comes slightly overprovisioned from the factory. However, that buffer is typically much smaller than the optimum value, meaning that the performance will drop as the drive gets close to full. How much it will drop depends on the implementation. For example, it obviously depends on the size of that unconditional minimal internal buffer.

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Note that many SSDs are factory over-provisioned. – Shinrai Feb 4 '13 at 17:33
How much space is "hidden"? Is it a set amount or a percent that changes as the drive gets filled? I guess that is what I need to know. My drive does not have that option, Kingston Hyper X, so although I understand that the drive will degrade in performance as it fills, I want to know what amount should be left free to maintain it's curent great performance. – Carl B Feb 4 '13 at 17:34
@AndreyT - Reviewing some articles, Over-provisioning is, it seems, done at the vendor level(setting up NAND for the SSD to use, but not the user or OS) while under-provisioning is an attempt of the user (Allocate space not to be used for OS or programs, but left free for the SSD). Correct? I could be wrong in my assumption. – Carl B Feb 4 '13 at 17:48
@Carl B: That might be true. However, the Samsung Magician utility that controls provisioning for Samsung SSDs uses the term "Over Provisioning" to refer to the user-controlled space reserve settings. Could be non-canon, of course... – AnT Feb 4 '13 at 18:02
IIRC, Samsung lets you mess with those settings, but most drives don't. Generally the excess space is completely off-limits unless you want to screw with the firmware on the drive. – Shinrai Feb 4 '13 at 18:12

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