Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I installed a solid state drive on my laptop, but I don't get the blazing speeds which people write about.

My system:

  • Laptop: Acer Aspire 7552G-6061
  • Solid state drive: Crucial 256GB M4 CT256M4SSD2
  • Operating system: Linux (Trisquel 5.5, a derivative of Ubuntu)

I am using AHCI.

I installed the operating system onto the solid state drive (as opposed to copying it).

How can I make the solid state drive faster? Could the problem be with the block or sector alignment?

share|improve this question
It would be helpful to know exactly what performance issues you are encountering. – Deltik Jun 6 '12 at 6:12
I didn't time things, but the bootup time might be a little faster, and the showdown time is about the same. When I open a 6 MB file in LibreOffice Calc, I can still see the progress bar move as Calc loads it. – wcyang Jun 6 '12 at 12:39
up vote 1 down vote accepted

Answering Your Questions First

  • The problem should not be related to sector alignment.
  • I have two tips below for keeping up performance on SSDs.

Understanding SSD Benefits

The "blazing speeds" people experience on solid-state drives are referring to reading from and writing to the drive. Compared to hard disk drives, SSDs have very low access times and higher data transfer rates, especially when accessing randomly.

Operations beyond reading and writing data to the SSD do not have a performance increase, such as using the processor to make intensive calculations. If your expectation from your SSD is to have performance improvements for CPU or RAM operations, this is why you aren't getting the "blazing speeds".

Did you notice your boot time decrease dramatically transitioning from an HDD to an SSD? I used to be frustrated at my laptop for taking over 50 seconds to boot. Now, with my own Crucial 256GB m4 CT256M4SSD2, my laptop boots in no more than 12 seconds (and this includes running a full LAMP server!)

When a computer is booting from an HDD, files have to be read from different physical locations. The seek time of the reading head moving to the next location is a huge performance killer. The Crucial m4 has an average access time of 0.1 ms. The hard drive I had before (a Toshiba MK6461GSYN) has an average access time of 15.8 ms. Not only is the SSD much faster, it also reads and writes over twice as fast (240+ MB/s) as my HDD can (120 MB/s maximum).

If you haven't experienced a huge decrease in boot time, I can't guess why from the information you provided. To some people who are wondering why I haven't suggested TRIM, it's because TRIM isn't relevant yet. TRIM is only useful for writing to the SSD, but booting an operating system is primarily reading.

Improving SSD Performance on Linux

There are only two things that I recommend.

  1. Enabling TRIM
  2. Setting noatime

Enabling TRIM

TRIM keeps the write performance of your SSD like-new by telling the SSD what sectors are no longer in use and thus, reducing write amplification.

In a terminal, run the command sudo nano /etc/fstab.

Use the arrow keys and find the entry or entries that are partitions on your SSD. For each entry, add discard to the options. A line may look something like this afterwards:

UUID=ed586ab8-08c5-4bae-b118-d191b716b4a4 /               ext4    discard,errors=remount-ro 0       1

Skip to the section below to apply noatime as well, or press CtrlX, type Y, then press Enter to save the changes.

Setting noatime

noatime tells the filesystem not to write to files when they were last accessed. Logging latest access times, in most cases, is not necessary and is a waste of effort on both SSDs and HDDs.

Like the section above, make sure that you've run the command sudo nano /etc/fstab and are in the nano text editor.

Use the arrow keys and find the entry or entries that are partitions on your SSD. For each entry, add noatime to the options. A line may look something like this afterwards:

UUID=ed586ab8-08c5-4bae-b118-d191b716b4a4 /               ext4    noatime,discard,errors=remount-ro 0       1
share|improve this answer
Possibly some of my usage is CPU- and RAM-intensive. Your answer was informative, and including examples was good. I know nano, but it was nice that you went through the steps for saving. – wcyang Jun 6 '12 at 12:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .