My Crucial M4 likes running Trim

IngerMan · Feb 27, 2012

Last week I got my early 2011 15" MBP. I installed the Crucial M4 256GB in the main bay right away, along with 8GB of ram. I tested the drive with diskspeedtest right away and got 270 write and 490 reads. But after a few hours of adding apps and moving some stuff I never was able to hit that write speed again. It seemed I lossed about 7-8% write speed, which is still pretty impressive. I checked it a 3 - 4 times a day for the next 4 days.

I installed Trim support enabler 2.1 this weekend. I did the erase free space after installing. Boom-- I got back my 8%. I have added 20 GB of Apeture library and I have removed 10GB of iPhoto. Every time I run disk speed test I get 270+ write. With out it I was 240' - to low 250's.

My thoughts are that Apple (Lion & 10.6.8) included Trim with all their SSD (samsung, toshiba). Lion is made for Trim support. I took a very small sample but I like what I have seen. I am leaving it on for the duration.

fisherking · Feb 27, 2012

i opted to NOT run trim enabler for my M4 (after talking to crucial support, who said trim was not needed).

i haven't run any benchmarks, but my mbp seems to be running no differently after about 3 months of intensive use...

anyone else?

Ccrew · Feb 27, 2012

fisherking said:
i opted to NOT run trim enabler for my M4 (after talking to crucial support, who said trim was not needed).

i haven't run any benchmarks, but my mbp seems to be running no differently after about 3 months of intensive use...

anyone else?

AnandTech's reviews of the drive said that trim would benefit it because it's built in garbage collection generally sucked. "Without TRIM the m4 can degrade to a very, very low performance state"

http://www.anandtech.com/show/4253/the-crucial-m4-micron-c400-ssd-review/2

fisherking · Feb 27, 2012

Ccrew said:
AnandTech's reviews of the drive said that trim would benefit it because it's built in garbage collection generally sucked. "Without TRIM the m4 can degrade to a very, very low performance state"

http://www.anandtech.com/show/4253/the-crucial-m4-micron-c400-ssd-review/2

but crucial said..!

thanx for that article, am going to try enabling trim, see if i notice any differences...

IngerMan · Feb 27, 2012

fisherking said:
but crucial said..!

thanx for that article, am going to try enabling trim, see if i notice any differences...

I think since you have not had it on from the duration of being new, you should erase disk free space in disk utility after enabling trim. That worked for me but it did take about 20 minutes.

My 500th post I got an "a" for Apple...lol

squeakr · Feb 27, 2012

You can also do it by booting into single user mode (CMD + s) and then typing fsck -ffy at the root prompt and it will erase all free spec and prep for TRIM.

fisherking · Feb 27, 2012

IngerMan said:
I think since you have not had it on from the duration of being new, you should erase disk free space in disk utility after enabling trim. That worked for me but it did take about 20 minutes.

My 500th post I got an "a" for Apple...lol

gonna do that now... (since i've already enabled it...").

EDIT: the option to erase free disk space is greyed out (even when booting from a Lion DVD).
so...? how do i do this?

IngerMan · Feb 27, 2012

fisherking said:
gonna do that now... (since i've already enabled it...").

EDIT: the option to erase free disk space is greyed out (even when booting from a Lion DVD).
so...? how do i do this?

I am not sure why it would be greyed out. Look at were I have the drive highlighted. Maybe you need to repair permission first?

fisherking · Feb 27, 2012

IngerMan said:
I am not sure why it would be greyed out. Look at were I have the drive highlighted. Maybe you need to repair permission first?

did that (and disk first aid), all good, but still greyed out.

anyway, did the single-user boot thing, and all is well (so far).
will be interesting to see if things feel any different over time.

thx!

IngerMan · Feb 27, 2012

fisherking said:
did that (and disk first aid), all good, but still greyed out.

anyway, did the single-user boot thing, and all is well (so far).
will be interesting to see if things feel any different over time.

thx!

That's good. But as far as noticing a big change in normal usage. I would compare that to the MBA Toshiba vs Samsung SSD. I doubt you will notice in normal usage, unless you were at a point that it largely degraded.

Apple SSD's run garbage collection along side Trim support. Im going to run it as well, because I do not want too degrade.

Krazy Bill · Feb 27, 2012

Good as place as any to ask...

How does one "reset" an M4 SSD to factory-fresh, speedy condition? (I'm not talking about reformatting/erasing).

IngerMan · Feb 27, 2012

Krazy Bill said:
Good as place as any to ask...

How does one "reset" an M4 SSD to factory-fresh, speedy condition? (I'm not talking about reformatting/erasing).

That would be installing Trim Enabler 2.1, reboot, erase free disk space in disk utility or the above mentioned command.. Done!

Edit; Squeakr instructions to erase free space.

You can also do it by booting into single user mode (CMD + s) and then typing fsck -ffy at the root prompt and it will erase all free spec and prep for TRIM.

Erasmus · Feb 27, 2012

Just wondering, I am assuming that the degradation of performance due to poor garbage collection happens on a sector-by-sector basis, instead of a uniform degradation across the entire drive? Which would mean that running disk speed tests would likely be very hit-and-miss when it comes to identifying when a TRIM routine should be run?

IngerMan · Feb 27, 2012

Erasmus said:
Just wondering, I am assuming that the degradation of performance due to poor garbage collection happens on a sector-by-sector basis, instead of a uniform degradation across the entire drive? Which would mean that running disk speed tests would likely be very hit-and-miss when it comes to identifying when a TRIM routine should be run?

I will just say this. You do not have the option of turning it off on an Apple SSD. It is alway on.

Erasmus · Feb 27, 2012

IngerMan said:
I will just say this. You do not have the option of turning it off on an Apple SSD. It is alway on.

True, but Apple don't provide Crucial m4 SSDs. Furthermore, I would assume that running TRIM would consume a small amount of CPU and RAM resources, so switching it off would result in marginally better performance.

I would also assume that the TRIM function would expedite extra write cycles that would otherwise not occur, marginally decreasing the expected life of the drive.

Ccrew · Feb 27, 2012

FYI all. The "Erase Free Disc Space" option is indeed greyed out by design. The correct way to do it is squeakr's instructions.

squeakr · Feb 27, 2012

The TRIM algorithm is set to perform load leveling and to clean the free space as well, so that the wear is negated to a certain level. It is not something that gets turned on and off at will. Turn it on and leave it on. The disk manufacturer doesn't make a difference with regards to TRIM, it is an OS feature and not something for a specific disk.

negativzero · Feb 27, 2012

Erasmus said:
True, but Apple don't provide Crucial m4 SSDs. Furthermore, I would assume that running TRIM would consume a small amount of CPU and RAM resources, so switching it off would result in marginally better performance.

I would also assume that the TRIM function would expedite extra write cycles that would otherwise not occur, marginally decreasing the expected life of the drive.

Trim does not consume any resources. It is only run when the empty trash bin button is pushed.

As a guide on whether to use Trim on the M4. Don't take what Crucial, Anandtech, etc... tell you to heart. The M4 employs something called idle time garbage collection, meaning its garbage collection only starts when the drive is idle or when they're aren't much writes done to it. So if you're constantly abusing your M4 by downloading or doing lots of video/audio encoding, it will be a wise choice to have Trim enabled on it. Otherwise if you are a light user, the native garbage collection will work fine in keeping the SSD in top condition.

Spink10 · Feb 27, 2012

negativzero said:
Trim does not consume any resources. It is only run when the empty trash bin button is pushed.

As a guide on whether to use Trim on the M4. Don't take what Crucial, Anandtech, etc... tell you to heart. The M4 employs something called idle time garbage collection, meaning its garbage collection only starts when the drive is idle or when they're aren't much writes done to it. So if you're constantly abusing your M4 by downloading or doing lots of video/audio encoding, it will be a wise choice to have Trim enabled on it. Otherwise if you are a light user, the native garbage collection will work fine in keeping the SSD in top condition.

That makes sense - where did you get this info? You have a link - Im interesting in understanding more about this. I currently run a Vertex 3 MAX with no TRIM.

negativzero · Feb 27, 2012

Spink10 said:
That makes sense - where did you get this info? You have a link - Im interesting in understanding more about this. I currently run a Vertex 3 MAX with no TRIM.

You can check this white paper from OCZ.
http://www.oczenterprise.com/whitepapers/ssds-write-amplification-trim-and-gc.pdf

But like I said, all SSDs are different. If you're running SF-2281 and newer controllers, you don't need trim at all because they use active garbage collection instead of idle time. So the trim command is on active in the controller and you don't need to enable it.

Spink10 · Feb 27, 2012

negativzero said:
You can check this white paper from OCZ.
http://www.oczenterprise.com/whitepapers/ssds-write-amplification-trim-and-gc.pdf

But like I said, all SSDs are different. If you're running SF-2281 and newer controllers, you don't need trim at all because they use active garbage collection instead of idle time. So the trim command is on active in the controller and you don't need to enable it.

Thanks!

My Crucial M4 likes running Trim

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