SSD.. why garbage collection isn't as good as TRIM

[omega3]

Just found this test about Performance Degradation, Garbage Collection and TRIM

As i mentioned in my other thread.. I'm stuck with VISTA on the laptop i am considering getting an SSD, which does not support TRIM.

Alot of people say that if i get the Samsung 840 EVO for example, i could rely on its built-in garbage collection and the Magician software for TRIM.

However, if I look at the above benchmarks for the 840 EVO (and many other SSDs), it seems that garbage collection after 30 minutens only restores a little bit of the initial performance and that only the OS TRIM gets it back to full speed.

Now.. keep in mind me having Vista.. does software like Samsung Magician has a TRIM feature built in that is just as good as OS TRIM, cause if you have to rely on just garbage collection, the numbers don't look good.

I really wonder if software TRIM can be as good as TRIM by the operating system.

Anybody has Samsung Magician and can tell me more?

Final question.. why do i read so often it's not good to have your large multimedia data files on an SSD.. why not?? or is this outdated?

 

[Elixer]

Not sure why you are making multiple threads, since this was discussed in your other thread.
As I mentioned in your other thread, if your usage is light to medium, don't worry about trim.
If you are a heavy user, with constant writing & deleting files and you use up most of the SSD's space, then get a SSD that has a utility to do manual trim.

These so called tests that you see are NOT real world usage. They fill the whole drive up with data, then delete things, then they wait to see how GC works.
The 840 is not a good SSD, it still suffers from slowdowns for some people because of 'stale' data.

 

[VirtualLarry]

Now.. keep in mind me having Vista.. does software like Samsung Magician has a TRIM feature built in that is just as good as OS TRIM, cause if you have to rely on just garbage collection, the numbers don't look good.
Yes, toolbox TRIM tools do the same thing as OS TRIM commands. The only difference is, they clean up the drive all at once, by scanning the filesystem for unused blocks, and sending TRIM commands for them. OS TRIM, at least in Windows 7 and newer, sends a TRIM command to the drive after every deleted block. The overall effect is the same, however.

Final question.. why do i read so often it's not good to have your large multimedia data files on an SSD.. why not?? or is this outdated?

It doesn't really matter, but SSDs are more expensive than HDDs, and more performance-oriented, so generally, at least when SSDs were on average a smaller size, you would only put your OS and essential applications on the SSD, and your media files on the HDD. They don't hurt the SSD by storing them on the SSD, but it's a question of opportunity cost.

 

[VirtualLarry]

The 840 is not a good SSD, it still suffers from slowdowns for some people because of 'stale' data.

This, too.

If you look at that diagram from the above-linked review at XBitLabs, I would go with one of the top two SSDs in that chart, because it is obvious that they have aggressive garbage-collection, since the bottom two bars are nearly the same. IOW, their GC is aggressive enough, that it is performance-equivalent to a system with an OS that sends TRIM commands.

I was wrong about the 530, not only does it have weak and ineffective GC, it also doesn't recover performance back to out-of-box speeds even with TRIM.

 

[SSBrain]

On many SSDs it takes more than 30 minutes to recover most of their speed through GC after thrashing them with writes. Eventually (on non-Sandforce ones), after a few hours of idling or light usage they will recover most of their write speed. I wouldn't call filling them two times their capacity of QD32 random writes as everyday or light/medium usage, however. This is a pretty much extreme usage case.

 

[omega3]

On many SSDs it takes more than 30 minutes to recover most of their speed through GC after thrashing them with writes. Eventually (on non-Sandforce ones), after a few hours of idling or light usage they will recover most of their write speed. I wouldn't call filling them two times their capacity of QD32 random writes as everyday or light/medium usage, however. This is a pretty much extreme usage case.

Are Sandforce drives perhaps better in that regard cause i read alot of people recommending getting a sandforce drive if still on Vista?

Which 250gb would you recommend that is in the same price range as Crucial MX100 or Evo 850 (non-pro)?

 

[SSBrain]

Sandforce-based drives perform data compression, which means that they write on their memory less data than the user requests. This lowers the write amplification and ultimately, NAND wear to a level which makes it irrelevant in practice whether TRIM is enabled or not.

I seem to remember they have long-standing bugs with TRIM, causing a slight long term, permanent write speed degradation with incompressible data (which can be only solved with a secure erase), so they're probably ironically better suited for systems without TRIM enabled.

I wouldn't really recommend getting one just for that, however.

Between the Crucial MX100 and the Samsung 850 EVO I would probably get the latter. The Samsung Magician software also has an option to run TRIM on the SSD, regardless of the OS support for that, so you could run that from time to time if you really wanted.

 

[Omar F1]

This, too.

If you look at that diagram from the above-linked review at XBitLabs, I would go with one of the top two SSDs in that chart, because it is obvious that they have aggressive garbage-collection, since the bottom two bars are nearly the same. IOW, their GC is aggressive enough, that it is performance-equivalent to a system with an OS that sends TRIM commands.

I was wrong about the 530, not only does it have weak and ineffective GC, it also doesn't recover performance back to out-of-box speeds even with TRIM.

Thanks for listing, very informative chart and I whish Anantech would implement such a similar test, I think it's useful for the average user than Anand's one.


So GC is non-OS dependent feature and should work well with Vista/XP.