Solid State Drives: do you keep 10-20% empty?

[Darren Dirt]

also, some other tips
http://www.howtogeek.com/howto/45359/htg-explains-whats-a-solid-state-drive-and-what-do-i-need-to-know/

[Tom]

I'm not entirely sure they know what they are talking about.

[Lazybones]

Don?t defragment your drive. Defragmentation is useless on a SSD and it decreases the lifespan. Defragmentation is a technique that brings the pieces of files closer together and optimizes their placement on the platters of HDDs to decrease the seek time and the wear and tear on the disk. SSDs have no platters and have a nearly instantaneous seek time. All defragging them does is chew up more of your write cycles. By default in Windows 7, defragmentation is disabled for SSDs.

This is sort of true, but really only applies to Windows since MacOS auto optimizes as it goes and Linux file systems do as well. Unless YOU have setup a very aggressive manual defrag the defaults will probable not hurt the drive.

Before imaging your system for a full restore of move to a new harddrive you will want to do one anyway to consolidate free space and make the image more consistant

Turn off Indexing Services: If your OS rocks any sort of search-supplementation tool like an Indexing Service (Windows does), turn it off. The read time is so fast on SSDs that you don?t really need to build a file index and the actual process of indexing the drive and writing the index is slow on SSDs.

All your data probably doesn't reside on the SSD drive, turning off indexing services in windows 7 or higher with Outlook 2007 will likely break search all together...

Your OS should support TRIM. The TRIM command allows your OS to communicate with your SSD drive and tell it which blocks are no longer in use (and are thus clear for wiping). Without the TRIM command taking care of some housekeeping on your SSD the performance will rapidly degrade. As of this publication Windows 7, Mac OS X 10.6.6+ and Linux Kernel 2.6.33+, support the TRIM command. While registry hacks and supplementary programs exist for modifying earlier OS versions like Windows XP to semi-support the TRIM command there is no native support. Your SSD should be paired with a modern OS for maximum performance.

Yes this is true. Although they don't completely explain it hear the reason that trim speeds things up is that it takes less time to write to an empty sector than to re-write/ refresh one with data in it on SSD.

Leave a portion of the disk empty. Check the specs for your drive, most manufacturers recommend keeping 10-20% of the drive empty. This empty space is there to assist the leveling algorithms (they redistribute the data across the NAND modules to minimize the total wear on the drive and ensure a long life and optimum drive performance). Too little space and the leveling algorithms work over time and prematurely wear on the drive.

Never heard of this.... I would love to see some documentation on it... It makes no sense.

Store media on a second drive: Until SSDs drop radically in price it makes no sense to store your massive media files on your expensive SSD. You can pick up 1TB traditional HDDs for under $100 now; use a large secondary drive (when possible) for storing your large and static files (such as movies, music collections, and other media files).

Never search this second drive since you where told to turn off indexing services above... it will take ages.

Invest in RAM: Compared to the cost of Solid State Disks, RAM is cheap. The more RAM you have the less writes-to-disk you?ll have on your OS disk. You?ll extend the life of your pricey SSD by ensuring your system has adequate RAM installed.

No qualifier on this on how much RAM is enough. An average users Desktop-Laptop probably wont go much faster past 8GB of ram and it will change depending on the OS.

They also don't warn you that specifically in windows your swap file, hibernate file and required disk space for a full dump (for a bluescreen) increase as you increase the RAM UNLESS you manually disable them or change them

[Tom]

With old SSDs, you wanted to keep some free, just to extend the life.

Two issues myself:

1. SSDs already keep a large chunk of reserved flash for wear leveling, and performance reasons (it can always keep a few pages erased, so you don't get into "Read-Modify-Write" storms when the drive is full).

2. TRIM as specified in the current SATA spec is horribly broken. The only thing it really does these days is slow down access to your drive if your OS actually uses it actively. Since its broken, most SSDs have their own algorithms to manage the wear leveling logic, and generally perform better than drives that exclusively use TRIM. AFAIK windows currently only occasionally sends TRIM/DISCARD requests, and does it in batches, in the background when the SSD isn't busy. It can help, but yeah, its not near as useful as it could be (it's being fixed in the newer specs).

In case you're interested in how TRIM is broken: It is specified as a barrier (full queue blocking/flushing operation). When a trim request is sent, the device has to first wait till the queue is clear, then does the operation while nothing else is happening or can happen. Often the TRIM request was implemented "inline" which also can take quite a while, since that should mean it does a full erase cycle on flash blocks (very slow process, in relative terms). Newer drives internally queue up the management of the newly TRIMed blocks, but it still blocks up the queue while the command is sent.