Short Stroking SSD

[Computurd]

I have heard of an optimization on another brand of ssd that is returning great results.
what they do is in essence create a short stroked ssd. you create a partition but leave approximately 35 percent of the drive empty. since the controller of the drive uses free space on the drive for drive functions they can get a boost of the performance on the ssd. it is refered to as 'over provisioning'. by increasing spare area you get a benefit.
has anyone heard of, tried, or have any feedback of this and idiliinx controlled drive usage?

[devsk]

Sooner or later, you are gonna run out of that too. Then what?

See? This is never ending fight. Only true and stable TRIM will solve this problem, so that firmware don't have to search for free blocks elsewhere.

[Computurd]

thats not the topic devsk. i am looking for an answer to a question, not another question.

[m.oreilly]

this all has to do with bench results, right? devsk's "you are gonna run out of that too..." is correct, to a point. wear leveling/gc, etc., takes time, period, and you loose some os real estate to boot. benches love "fresh" nand, so i look at this as a bench only "tweak". any over provisioning has the look of failure, as the FW decides how much "fresh" nand is sequestered for being "untouchable" by the os.

[Tony]

Drives are over provisioned from the factory already, Vertex has around 10GB extra on each drive for wear levelling. Newer drives from OCZ will have increased over provisioning.

Now, what you are saying is always leave 35% free to give the drive extra free nand to play with, this will work. I have actually forced a 250GB drive to except a 120GB flash ( you guys can not do this) as the drive had some damaged nand that pushed the max available to below the amount needed for a 250GB drive...so i had 230GB available. So now i have a 120GB drive with 110GB Nand over provisioning I never bench with this drive as its just to fast at recovering LOL

In the end i think its wise to leave at least 25% free, the fuller drives get the harder it will be for the controller to find clean nand to write to, hence they will slow down, especially if you write large files etc.

[reynoldsjrmy]

Is Short Stroking simply a matter of shrinking a volume in 'Disk Management' so that there is unallocated space or does the SSD need to be flashed appropriately?

I've got a Summit (Samsung Controller) - have you heard if this strategy is effective on it? I only use it as a System boot and application volume so I've got lots of freespace. I've just unallocated 25Gb of space - I'll let you know if I experience a change in performance and/or recovery in performance. If it works it's just so easy. Fascinating stuff - thanks.

[Computurd]

Yes, tony you mention that we cannont do it ourself? what if during win7 install we only allow it to install to a smaller partition? will that work in essence, or does the firmware have to be told to address that space correctly?
OR will the drive automatically use ANY free space for this purpose?

[Tony]

I should imagine that is what they are doing to leave 35% free

[Computurd]

Now the hard part...if the SSD is short stroked during OS installation, what about when the raid card (my situation) had already created the array? ,my guess would be best case scenario is to create a a smaller array (for those of us with raid cards), then leave the rest of it unpartitioned....hmmm someone needs to test!!

[Tony]

just shrink the primary partition within disk manager...job done

[Shadow_Dragon]

Over-provisioning NAND isn't new "tweak". Me&er already made a post (section 6b) about it a some time ago. Anand recently brought it up again in one of this latest storage-articles. Michael Schuette of "Lost Circuits" also made a small part in his article about this work-method. (And I'm sure there are plenty more articles who already mentioned it, so I can assure you, it has been tested )
Like Tony already says, basically every SSD is over-provisioned. Thing is that the user can increase the over-provisioning as much as he likes. Just make sure the OS doesn't uses that part of the NAND and you are all set.
I, for example, only use 25GiB of my drive, leave 5 GiB un-partitioned and the remaining 2 GiB is hidden by the controller. In February when I'm doing my update-cycle, I'm replacing the unpartitioned space with an HPA, so I don't have to count out my partitions every time.

Just a small remark: if you want to do some over-provisioning, you must be sure that the part you leave blank are empty blocks. So if you don't have TRIM and you just shrink your partition it won't have any effect, you just threw away some precious disk-space. So do a ATA Secure Erase (Sanitary Erase-tool) to mark those blocks as empty.

Have fun!

[m.oreilly]

better to use as cleaner, then shrink, but heck, i purposely leave 2/3 my array empty anyways. the FW will use what it needs to, whether formatted or not.

[devsk]

If you over-provision by 35%, your drive cost just went up by 53% (yeah, 53% for 120GB model) considering 120GB model. So, instead of 3$ per GB, you are spending 4.6$ per GB. I have no idea why anybody would do that to their wallet! ohh wait...just so that they could provide "fresh" NAND to the benchmarks...:-) Over provisioning done by the vendor is a smart idea, and works. Leave it at that!

There are many ways to maintain and get back 100% performance on these drives. And most of them don't involve wasting precious SSD disk space. But that's just me. Apologies if my post sounds harsh or over-critical.

[Skully]

If you over-provision by 35%, your drive cost just went up by 53% (yeah, 53% for 120GB model) considering 120GB model. So, instead of 3$ per GB, you are spending 4.6$ per GB. I have no idea why anybody would do that to their wallet! ohh wait...just so that they could provide "fresh" NAND to the benchmarks...:-) Over provisioning done by the vendor is a smart idea, and works. Leave it at that!

There are many ways to maintain and get back 100% performance on these drives. And most of them don't involve wasting precious SSD disk space. But that's just me. Apologies if my post sounds harsh or over-critical.

Nope it sounds/reads as being frugal.....

[devsk]

Nope it sounds/reads as being frugal.....

frugal doesn't apply to any SSD disk that I know of...