SSD Facts - FYI

[Spyderwebber]

I just learned something yesterday regarding Solid State Drives (SSD) and I thought i would share it as I have worked in the IT industry for 15 years and I had no idea ('course SSDs are fairly new and most of my clients stick to standard HDs). Sorry for the length.

 

I built the system in question about 4 years ago, and it has worked great for me. Last year, instead of rebuilding, I decided to add an SSD to the mix to improve performance, which it did. Over the year though, I noticed it was slowing in performance, and about a week ago, it started crashing intermittently. After talking to Crucial (the SSD's manufacturer), I found out that SSDs don't work at all like a standard HHD, and they require some additional attention to keep them working properly.

 

First, keep the firmware up to date. Second, read below.

 

A little info on Solid State Drives (SSD). Not all SSDs are created equal. Different manufacturers determine what is important because of their electronic circuit "gates" called NANDs, which only live so long, and the the fact you can write to an individual NAND but can only erase in blocks (large groups of data).

 

Unlike regular hard drives, SSDs don't have any idea which bits of data on your drive is valid or invalid (aka deleted). As a result, until the SSD is told to overwrite a section, it keeps all the data on the drive. This means it is constantly running out of free space. Fortunately, most have some free space set aside to ensure you are never completely out of space, but how aggressively they use the spare area determines performance.

 

If the drive uses aggressive recycling, performance will stay high, but the SSD won't have as long of a lifespan. If they are conservative in the recycling, the SSD will live longer, but performance will degrade as use continues. There are things that can be done to help this, like idle time garbage collection and ATA TRIM.

 

If the OS, system hardware, and the SSD support it, the ATA TRIM command is passed to the SSD whenever Logical Block Addresses (LBAs) aren't needed anymore. For example, Win 7 sends a TRIM command when a drive is formatted (all LBAs are removed), or when the Recycle Bin is emptied, or a file is Shift+Deleted. The SSD will use this info to mark the data in those areas as available for recycling.

 

So, TRIM sounds like the way to go, but unfortunately, its not supported on older motherboards or drives. You have to have a 7-series motherboard or Intel's RST for RAID drivers version 11 or greater for it to work.

 

Since my motherboard was so old, this wouldn't work for me. But I found that the Crucial M4 drive I purchased didn't support TRIM anyway. Instead, they have an automatic function on the SSD called Active Garbage Collection. Essentially, when the drive is idle, it gets rid of all the unnecessary data to maintain performance. The problem is the drive wants 6-8 hours of idle time to do the clean up and my drive (as with most) is never idle that long, so my SSD performance degraded to the point where it was out of space, thus the crashing.

 

Thankfully, this is easy to fix though. There are two ways to accomplish this. First, (this was what Crucial told me to do) you could turn off your computer, disconnect the power cable, disconnect the SATA cable from the SSD but leave the power cable connected, plug the system back in and turn it on, leaving it alone for 6-8 hours, then reversing the steps, but this requires a bit of knowledge to get inside the system, make sure you don't screw anything up, etc.

 

The easy way to do it is to reboot the system and entered the BIOS instead of letting the system boot up into the OS. The SSD is idle while in the BIOS, and you can leave it this way for a while so the drive can do its thing.

 

I did the above, and the system is up and running fast as it ever did, so this is now part of my scheduled monthly maintenance on my system.

 

Thanks for reading...

 

=F|A=Spyder aka Spyderwebber

[LA_Kings_Fan]

Nice write up Spidey ... I also have 2 SSD's ... a CRUCIAL M4 64 GB and a CRUCIAL M4 128 GB ...

 

IF you REALLY want the LOW DOWN on optimizing your SSD and Windows 7 / 8 then do some probing around over here ...

 

- http://www.overclock.net/t/1179518/seans-ssd-buyers-guide-information-thread

- http://www.overclock.net/t/1156654/seans-windows-7-install-optimization-guide-for-ssds-hdds

- http://www.overclock.net/t/1248358/seans-ssd-hdd-troubleshooting-guide

- http://www.overclock.net/t/1227609/storage-drivers-utilities-and-firmware-thread

- http://www.overclock.net/t/1227308/storage-essentials-thread

[rolf]

Unlike regular hard drives, SSDs don't have any idea which bits of data on your drive is valid or invalid (aka deleted). As a result, until the SSD is told to overwrite a section, it keeps all the data on the drive. This means it is constantly running out of free space. Fortunately, most have some free space set aside to ensure you are never completely out of space, but how aggressively they use the spare area determines performance.

If the drive uses aggressive recycling, performance will stay high, but the SSD won't have as long of a lifespan. If they are conservative in the recycling, the SSD will live longer, but performance will degrade as use continues. There are things that can be done to help this, like idle time garbage collection and ATA TRIM.

I think you give the incorrect reason to use TRIM.

A normal hard disk can overwrite a block. A SSD needs to 'clear' a block (writing either 0's or 1's, I never remember, I thought ones) and then write all data on it. Hence, the problem is that writing takes two actions. However, once the data is garbage, you can clear it, even though you don't immediately have to write it. When the disk is idle, it can do this, hence TRIM.

Also, since you always have to clear the data first, this will not influence the livespan, only the performance.

 

So, TRIM sounds like the way to go, but unfortunately, its not supported on older motherboards or drives. You have to have a 7-series motherboard or Intel's RST for RAID drivers version 11 or greater for it to work.

I always thought that it was the operation system that needed to support TRIM. However, the OS can make some 'requirements', for example the device has to be in AHCI mode (Win7).

It might be that you're right, but I've used TRIM on my E8400 and E2180, and I know that AMD-based motherboards also support TRIM, so your list is not (entirely) complete.

The problem is the drive wants 6-8 hours of idle time to do the clean up and my drive (as with most) is never idle that long, so my SSD performance degraded to the point where it was out of space, thus the crashing.

Weird requirement Also, according to Wikipedia on TRIM, the integrated garbage collection works more aggresive than the TRIM, leading to a slightly less live span.

Anyway, that's why I now would recommend the Intel series, Samsung 830 or OCZ's without SandForce controller (those gave issues). In price it ain't that much extra these days, although the m4 was (a lot) better priced a couple of months ago.

 

Nice article tho In terms of performance it truely is the best upgrade to any PC I did in the last couple of years. I have a 830 256GB SSD in my laptop and two X25-m's from my old PC's, one now in my server (still old pc ), one as test-disk in my laptop for other OS'es, which I swap with my 830. Old mechanical hard disks are only used for boring storage for me these days, SSD's are the way to go

[Jefke]

Doesn't the intel series also use a sandforce controller (with lot's of optimization and fixing the problems with it). I know they used to use marvell controllers and switched over to sandforce based one.

 

I don't trust the ocz anymore, had loads of problems with them, I know they are solved, but I blacklisted the whole brand (and in lesser degree the sandforce controller ).

I now most of the time go for samsung 830 (got them in pretty much all the pcs in my home => 7: 6x 128gb and 1x 256gb). All the storage is done on our 2 nas systems.

 

Still I have to remember that solution for the crucial m4, I got some friends for who I build a pc with a crucial m4 in it.

Edited September 15, 2012 by DrJoske

[rolf]

It is not that the SandForce controller is bad, but the SSD does not only exists of the SandForce controller and some NAND chips, it also consists of software managing everything. And apparently, Intel is capable of writing stable software when using the SandForce controller. And OCZ on the other hand really isn't. But I haven't heard any recent issues with the OCZ without SandForce recently, other than that it didn't work in my current laptop.

[Jefke]

It is not that the SandForce controller is bad, but the SSD does not only exists of the SandForce controller and some NAND chips, it also consists of software managing everything. And apparently, Intel is capable of writing stable software when using the SandForce controller. And OCZ on the other hand really isn't. But I haven't heard any recent issues with the OCZ without SandForce recently, other than that it didn't work in my current laptop.

 

I know that, wasn't sure intel was using it (quick search 5s after post learned me I was right XD)

[rolf]

Intel didn't use it in its older SSD's. The Intel 520 and 330 are the only ones with SandForce, before that they used Marvells or mainly its own controllers. On the other hand, the 330 and 520 are the only one now in (large) production The X25-m where distinguishable compared to other brands (mainly Kingston, OCZ, Mtron, etc) in price/quality at that time, but now they're just average. And with the m4 as cheaper alternative and 830 as faster, Intel and OCZ, pioneers in the SSD world, are not that special anymore. Unless you go for extremes (OCZ Revodrive Although with lacking support and stability...)

[Jefke]

Intel didn't use it in its older SSD's. The Intel 520 and 330 are the only ones with SandForce, before that they used Marvells or mainly its own controllers. On the other hand, the 330 and 520 are the only one now in (large) production The X25-m where distinguishable compared to other brands (mainly Kingston, OCZ, Mtron, etc) in price/quality at that time, but now they're just average. And with the m4 as cheaper alternative and 830 as faster, Intel and OCZ, pioneers in the SSD world, are not that special anymore. Unless you go for extremes (OCZ Revodrive Although with lacking support and stability...)

 

. I know they used to use marvell controllers and switched over to sandforce based one. I knew that too

 

Crucial m4 is in Belgium more expensive atm than the samsung 830 btw, so I always go for the samsung ones.

[Spyderwebber]

Thanks for the additional input. As I did state, the use of SSDs is fairly new to me. As for the affect on the lifespan, I was referring to the more aggressive the clean up and the finite life of the NAND chips. The more clears/writes that occur, the shorter lifespan, but that was based on info I found in my research and not from experience, so I can't say its a fact or anything. Good to know about the TRIM. It doesn't work on my board, but if it can on others, that good to know. Your point is well taken. Its always best to check before assuming.