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This question already has an answer here:

Having read a number of SSD reviews, in particular, of those made by Crucial (a.k.a Micron), I've come to the conclusion that partitioning an SSD is going to make it slower. Here is the logic:

Those reviews explained that (at least the Crucial SSD's based on Marvel controllers) are essentially a RAID array of memory chips soldered to the board, invisible to the end-user as separate entities. I recall one or more of the reviews explicitly stated that the smaller capacity drive sequential access speeds were lacking because it had only half the number of chips of the larger drive. The slowdown was almost linear according to their testing. Thus, I conclude that when I partition such a drive, only a part of the chips are going to be in the partition, thus I'm going to suffer from the said linear slowdown.

Is the above true for Marvell based Crucials? For other drives such as Samsung-controller based, Sandforce-based, others? I'm particularly interested in the Crucial drives, them being the best bang for the buck right now. I'd be happy to also RAID a couple of those on an X79, but totally unsure about partitioning that either. However, that would be a separate question, and not a part of this one, so I'd like to first firgure out partitioning a single SSD drive.

marked as duplicate by sawdust, DavidPostill, fixer1234, mdpc, Hennes Mar 18 '16 at 13:53

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.

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    Considering the drives already use whatever cells they desire for whatever address and there is no 1:1 mapping, the partitions can reside anywhere in the chips. – Sami Kuhmonen Mar 13 '16 at 17:56
  • I don't think partitioning make any difference to speed in an SSD drive, as @SamiKuhmonen mentioned, there is no 1:1 mapping like in a spinning drive (normally), the drive will utilize the cells where if it wishes... How you partition it is not relevant. I have several SSD drives, benchmarking is pretty consistent whether it is one large volume or multiple smaller volumes. – acejavelin Mar 13 '16 at 18:15
  • Since IDE, we should not even be concerned with internal strategies. The only issue with partitioning to affect performance in any way is alignment of the boundaries to geometry favored by the manufacturer. (Cylinder preferably, even though this is abstracted). – mckenzm Apr 2 '16 at 21:28
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It makes no sense/logic.

Those reviews explained that (at least the Crucial SSD's based on Marvel controllers) are essentially a RAID array

So it's a bad idea to partition RAID array too? That's new to me.

I recall one or more of the reviews explicitly stated that the smaller capacity drive sequential access speeds were lacking because it had only half the number of chips of the larger drive.

But partitioning doesn't make your drive smaller. It's just a big drive, or big RAID in your word, "shared" by multiple partitions.

Thus, I conclude that when I partition such a drive, only a part of the chips are going to be in the partition

A partitioned RAID-0 doesn't make it a JBOD.

  • I had absolutely no idea about the effect of partitioning a RAID before asking, thats' why I asked the question in the first place. As well as I had no idea on how the data gets distributed on the RAID. – iksemyonov Mar 14 '16 at 15:38
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You already have an useful answer here: Disadvantages of partitioning an SSD?

According to @RobinHood answer, there are small differences regarding the SSD being Ram based or Nad-flash based devices. You'll only have a minor speed disadvantage (outlined below) in the case of Nand-flash based SSDs:

Ram Based S.S.D.s:

There is absolutely no disadvantage because they are random access!

Nand-flash Based S.S.D.s:

The only disadvantages that come to my mind would be:

  1. Wear leveling won't have as much free space to play with, because write operations will be spread across a smaller space , so you "could", but not necessarily will wear out that part of the drive faster than you would if the whole drive was a single partition unless you will be performing equivalent wear on the additional partitions (eg: a dual boot).
  2. Like hard drives nand-flash S.S.D's are sequential access so any data you write/read from the additional partitions will be farther away than it "might" have been if it were written in a single partition, because people usually leave free space in their partitions. This will increase access times for the data that is stored on the additional partitions.
  3. Less total space increases the likely hood of writing fragmented files, and while the performance impact is small keep in mind that it's generally considered a bad idea to defragement a nand-flash S.S.D. because it will wear down the drive. Of course depending on what filesystem you are using some result in extremely low amounts of fragmentation , because they are designed to write files as a whole whenever possible rather than dump it all over the place to create faster write speeds.
  • Copying someone else's SU answer to use as your own (even if you give credit) and adding no new insight seems like a form of plagiarism. Downvoted. You only deserve credit for finding a duplicate question that has an answer. – sawdust Mar 14 '16 at 0:22
  • Sorry @sawdust, I'm new here. What should I have done then? Don't answer? Anyway I have to disagree with you. Searching for answers is also what science does, review articles seek to synthesize and summarize the work of a particular sub-field, rather than report on new results. And that also contributes to spread knowledge and authors are also given credit for their research. As in this case, extracting from a broader answer (disadvantages of partitioning a SSD) the exact contribution for this specific question (speed disadvantages) is not a contribution itself that helps with this issue? – Naceira Mar 14 '16 at 4:09
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    I also thought this was not about credit, but about spreading good knowledge. This is an extract from the help section in this site: "When you find a useful resource that can help answer a question (from another site or in an answer on Super User) make sure you do all of the following: Provide a link to the original page or answer Quote only the relevant portion Provide the name of the original author" I think I've done all the above mentioned... so your comment and downvote, IMHO are much out of place. Help page - How to reference material – Naceira Mar 14 '16 at 4:12
  • Giving credit and spreading good knowledge is indeed laudable, however you are spreading misinformation. – Ben Voigt May 29 '16 at 20:28

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