# Problem with TRIM on SSDs



## -dc (Oct 2, 2019)

I have a pb with TRIM.
It works on two drives (internal), but not two others (connected via USB3).
Is it the controller?  How can that be?
*How can I enable TRIM for all external (USB) drives?*
Some indications below.
Many thanks in advance for your help.
Best wishes, David 

On W7 (64),  Command prompt:    DisableDeleteNotify = 0
So TRIM is enabled

Hard Disk Sentinel gives the following

SSD 850 EVO 500GB = one of the two disks where TRIM works.
Performance 100%
Health 100%
“The TRIM feature of the SSD is *supported and enabled*”
Disk Controller:  Standard Dual Channel PCI IDE Controller (ATA) [VEN: 1002, DEV: 4390] Version: 6.1.7601.18231, 6-21-2006

SSD 860 QVO 2TB = one of the two disks where TRIM does *NOT* work.
Performance 80%
Health 100%
“The TRIM feature of the SSD is *supported but disabled*.”
Disk Controller:  Renesas Electronics USB 3.0 Host Controller (USB 3.0) [VEN: 1033, DEV: 0194] Version: 2.1.36.0, 5-10-2012


----------



## newtekie1 (Oct 2, 2019)

Most USB to SATA controllers don't properly support TRIM.  So chances are, you can't enable TRIM on the SSDs connected to USB.


----------



## -dc (Oct 3, 2019)

Many thanks for your reply.

So, if TRIM will not pass through on USB, I am thinking that I could get a PCI controller card with an eSATA connector cable – and that passes TRIM.  Would that do the trick?  Can you recommend one (make, model, ref)?  Especially one that also provides the power supply?

Do we know why TRIM will not pass via USB?  Why have the USB designers not built that in?

Many thanks again – great help - david


----------



## Athlonite (Oct 3, 2019)

USB3 has brought a new protocol : UASP (USB Attached SCSI Protocol) for communication with external mass storage devices over USB. The old protocol BOT (Bulk Only Transport) does not support TRIM. UASP supporting TRIM and NCQ

so what you'll need is a supporting USB3.0 2.5" or M.2 case that supports the UASP protocol


----------



## TheLostSwede (Oct 3, 2019)

-dc said:


> Many thanks for your reply.
> 
> So, if TRIM will not pass through on USB, I am thinking that I could get a PCI controller card with an eSATA connector cable – and that passes TRIM.  Would that do the trick?  Can you recommend one (make, model, ref)?  Especially one that also provides the power supply?
> 
> ...



It's not a matter of the USB designers no doing it, it's a matter of the device makers using old USB 3.x controllers and not giving a shit.
You need a controller with UASP support that also supports UNMAP.
So as pointed out a few seconds ahead of my comment, you have some older USB to SATA controllers in your drive enclosures, hence the lack of TRIM support.


----------



## hojnikb (Oct 3, 2019)

Any particular reason, why you need TRIM?

While it's a great feature, it's not strictly required for SSD to work. Without TRIM, you lose some write performance and get some more wear. Nothing to be alarmed about.


----------



## TheLostSwede (Oct 3, 2019)

hojnikb said:


> Any particular reason, why you need TRIM?
> 
> While it's a great feature, it's not strictly required for SSD to work. Without TRIM, you lose some write performance and get some more wear. Nothing to be alarmed about.


The OP is using a QLC SSD, he's going to want TRIM support for that, as it'll wear out much quicker without it.


----------



## newtekie1 (Oct 3, 2019)

TheLostSwede said:


> The OP is using a QLC SSD, he's going to want TRIM support for that, as it'll wear out much quicker without it.



TRIM has nothing to do with how quickly an SSD wears out.


----------



## hojnikb (Oct 3, 2019)

newtekie1 said:


> TRIM has nothing to do with how quickly an SSD wears out.



Actually, it does. Having no trim support means higher write amplification (as SSD has no idea which blocks are deleted or invalid) which in turn increases wear. That being said, it still shouldn't be an issue, even with QLC SSD.



TheLostSwede said:


> The OP is using a QLC SSD, he's going to want TRIM support for that, as it'll wear out much quicker without it.


True, but there is a bigger issue at stake here. If this an external drive, it won't be constantly under power. That can be potentially very bad, as QLC flash doesn't really have good data retention and frequent rewrites of old data are required. Now on a internal drive, this isn't an issue. But with an external drive which could potentially not be used months at a time, this can be an issue.


----------



## newtekie1 (Oct 3, 2019)

hojnikb said:


> Actually, it does. Having no trim support means higher write amplification (as SSD has no idea which blocks are deleted or invalid) which in turn increases wear. That being said, it still shouldn't be an issue, even with QLC SSD.



That's not how it works.  All trim does is clear the cell after it has been marked as deleted so during the next write to the cell you don't have to wait for the cell to clear before it can be written.  TRIM has no affect on SSD wear.  Without TRIM the only difference is the cell might not be cleared before a write command happens so it has to be cleared during the write making the write take longer.  There is no extra writes caused by not having TRIM, so the SSD doesn't wear out quicker.


----------



## hojnikb (Oct 3, 2019)

newtekie1 said:


> That's not how it works.  All trim does is clear the cell after it has been marked as deleted so during the next write to the cell you don't have to wait for the cell to clear before it can be written.  TRIM has no affect on SSD wear.  Without TRIM the only difference is the cell might not be cleared before a write command happens so it has to be cleared during the write making the write take longer.  There is no extra writes caused by not having TRIM, so the SSD doesn't wear out quicker.



Not, you have it wrong. All trim command does is tell SSD what data is effectivly invalid (or deleted if you will). Trim on it's own doesn't do any erasing of any sort.

Now, if ssd has the exact idea which block is invalid (and can be scheduled for eraseure) and which is actually valid (holds usable data) means much more efficient garabage collection and wear levelling. When SSD shuffles data around to evenly wear out cells and erases pages, it can do that job much more efficiently if it knows exactly which blocks can be erased. If there's no trim, SSD will assume that data, which was marked by filesystem by deleted is still valid up until you'll write something else in the same sector. This means lots more invalid data gets shuffled around for no apperent reason and in turn increasing write amplification.

This along with better write speeds is the sole reason why trim exists in the first place.


----------



## -dc (Oct 4, 2019)

hojnikb said:


> Actually, it does. Having no trim support means higher write amplification (as SSD has no idea which blocks are deleted or invalid) which in turn increases wear. That being said, it still shouldn't be an issue, even with QLC SSD.
> 
> True, but there is a bigger issue at stake here. If this an external drive, it won't be constantly under power. That can be potentially very bad, as QLC flash doesn't really have good data retention and frequent rewrites of old data are required. Now on a internal drive, this isn't an issue. But with an external drive which could potentially not be used months at a time, this can be an issue.



What is QLC?
Does that mean that an SSD not used for a long time can simply loose data?


----------



## bonehead123 (Oct 4, 2019)

-dc said:


> What is QLC?



hahahaha.......

.00132ns google search say you not know QLC means, you should stick with your Timex L-439 smartwatch .....


----------



## hojnikb (Oct 4, 2019)

-dc said:


> What is QLC?
> Does that mean that an SSD not used for a long time can simply loose data?


QLC is 4 bits per cell flash

Yes, theoretically, it can start losing data.


----------



## -dc (Oct 4, 2019)

hojnikb said:


> QLC is 4 bits per cell flash
> Yes, theoretically, it can start losing data.


Thanks.
In theory I understand, but in practice?  For example, can i leave my ssd in a dark cupboard for ten years and have no more data on it?


----------



## eidairaman1 (Oct 4, 2019)

hojnikb said:


> Any particular reason, why you need TRIM?
> 
> While it's a great feature, it's not strictly required for SSD to work. Without TRIM, you lose some write performance and get some more wear. Nothing to be alarmed about.



Erm trim is necessary, unless you want the drive to be full of rubbish

Its like fragmentation on a HDD.

Please do your research.


----------



## hojnikb (Oct 5, 2019)

eidairaman1 said:


> Erm trim is necessary, unless you want the drive to be full of rubbish
> 
> Its like fragmentation on a HDD.
> 
> Please do your research.



Nope, it's not necessary. SSDs were a thing long before there was trim command. And some ssds even after trim was out didn't really rely on it's support much (like sandforce drives).

Not to mention almost every other device (like flash drives or sd cards) that don't even support it, but work just fine.


----------



## TheLostSwede (Oct 5, 2019)

hojnikb said:


> Nope, it's not necessary. SSDs were a thing long before there was trim command. And some ssds even after trim was out didn't really rely on it's support much (like sandforce drives).
> 
> Not to mention almost every other device (like flash drives or sd cards) that don't even support it, but work just fine.


They still had garbage collection...
It might not have been called TRIM, as it wasn't a standard, but it did something similar, maybe just not as efficiently. Also, SD cards and any half decent USB drive has some form of garbage collection.


----------



## cucker tarlson (Oct 5, 2019)

use manual trim.should be fine for a data drive.
adata ssd toolbox has a trim command that'll work on any drive.
trim is necessary indeed.


----------



## eidairaman1 (Oct 5, 2019)

hojnikb said:


> Nope, it's not necessary. SSDs were a thing long before there was trim command. And some ssds even after trim was out didn't really rely on it's support much (like sandforce drives).
> 
> Not to mention almost every other device (like flash drives or sd cards) that don't even support it, but work just fine.



It is necessary, because they slowdown without clean up but you keep on running it in your own way and you will learn the hardway in the end from ignorance and neglect.


----------



## hojnikb (Oct 5, 2019)

TheLostSwede said:


> They still had garbage collection...
> It might not have been called TRIM, as it wasn't a standard, but it did something similar, maybe just not as efficiently. Also, SD cards and any half decent USB drive has some form of garbage collection.



again, trim and garbage collection are two completely different things in an ssd. Garbage collection is absolutely essential for any nand flash based device and no nand controller wont be with somekind of GC. Trim on the other hand as mentioned is just an aid to the garbage collection, so it can do its job more efficiently. But its not necessary.



eidairaman1 said:


> It is necessary, because they slowdown without clean up but you keep on running it in your own way and you will learn the hardway in the end from ignorance and neglect.



Well, unlike you, i speak from experience. TRIM is _not_ required and there won't be mayor slowdowns on modern flash controllers. The only real difference will be slower write performance (not noticeable with everyday usage) and higher write amplification. I deployed a bunch of SSDs on legacy WinXP builds and all of them work flawlessly without any slowdowns.


----------



## cucker tarlson (Oct 5, 2019)

hojnikb said:


> Well, unlike you, i speak from experience. TRIM is _not_ required and there won't be mayor slowdowns on modern flash controllers. The only real difference will be slower write performance (not noticeable with everyday usage) and higher write amplification. I deployed a bunch of SSDs on legacy WinXP builds and all of them work flawlessly without any slowdowns.


there are slowdowns.tested it.

got a su900 drive that for some reason needs trim to be executed manually (despite it says it's working).the file copy transfers and r/w speeds are in the dumpster unless I trim manually.


----------



## hojnikb (Oct 5, 2019)

cucker tarlson said:


> there are slowdowns.tested it.
> 
> got a su900 drive that for some reason needs trim to be executed manually (despite it says it's working).the file copy transfers and r/w speeds are in the dumpster unless I trim manually.



TRIM has _absolutely_  I REPEAT, absolutely no effect on _reading_ files. This, if happens, is a completely separate issue.
Must have been issue on your part, SM2258 controller has no reported issues with trim or any reason to manually trigger it.


----------



## cucker tarlson (Oct 5, 2019)

hojnikb said:


> TRIM has _absolutely_  I REPEAT, absolutely no effect on _reading_ files. This, if happens, is a completely separate issue.


but a big impact on write


----------



## hojnikb (Oct 5, 2019)

cucker tarlson said:


> but a big impact on write



Serious write slowdowns only happen when you hit the SLC buffer hard (as native write speeds are pretty weak with tlc or qlc flash nowadays). Just removing trim won't kill write performance tenfold. You might lose 10-20% (highly depends on firmware and flash controller) but not anything serious to be noticeable.


----------



## cucker tarlson (Oct 5, 2019)

hojnikb said:


> Serious write slowdowns only happen when you hit the SLC buffer hard (as native write speeds are pretty weak with tlc or qlc flash nowadays). Just removing trim won't kill write performance tenfold. You might lose 10-20% (highly depends on firmware and flash controller) but not anything serious to be noticeable.


well if you hit the buffer then you'll lose much more than 20% on some drives.


----------



## hojnikb (Oct 5, 2019)

cucker tarlson said:


> well if you hit the buffer then you'll lose much more than 20% on some drives.



Yes, write speed can drop to 5400rpm hdd levels, but that's an entirely separate issue, not related to trim.


----------

