free space and ssd health

[Light]

To maximize SSD life, how much free space should be left on the ssd now?

 

Does it matter if it is free space on a partition, or unpartitioned space?

[John Ratsey]

I think there are two possible reasons for leaving some unpartitioned free space: One is to have a supply of usable space for reallocation should the drive software find some bad blocks (I think some SSDs keep some reserve space which is never available to the user). The other reason for some free space is to facilitate garbage management. My rule of thumb is 5% subject to a minimum of 50GB (my recent SSDs are 1TB or larger). However, I think the minimum sensible free space will also depend on usage patterns. If there's a lot of changing and writing of files then there's more garbage.

 

However, I've not had SSD problems for about 10 years as SSD capacities have increased. I did have problems with early low capacity mSATA SSDs which I had filled so they lacked free space and there were times when the computer slowed to a crawl as the system had to do a lot of tidying up in order to write a file.

[saturnotaku]

Even if you do absolutely nothing to the drive, you will almost certainly upgrade/replace it long before NAND flash wear becomes remotely close to an issue.

[John Ratsey]

25 minutes ago, saturnotaku said:

Even if you do absolutely nothing to the drive, you will almost certainly upgrade/replace it long before NAND flash wear becomes remotely close to an issue.

Good point. My comment had focussed on performance. Here's some SMART data for a 2TB Sabrent Rocket I bought several years ago. The manufacturers' claimed life is measured in hundreds of Terrabytes written (TBW). That SSD has accumulated 18TBW in over 6000 hours of operation.

 

[Aaron44126]

Think about how high the warranty TBW value is and how long you might want to use the drive.

 

Let's look at, for example, Samsung 980 Pro.  The 1TB version is 600 TBW for warranty purposes.  Samsung is confident that you can write 600 TB to the drive to the point that they will replace it for you if it fails before then.

 

Let's say you think you might keep it for five years (which happens to be the warranty period).  600 TBW ÷1825 days = 336 GB per day you would have to write to the drive to hit the TBW limit before the five-year warranty is up, or about one third of the drive's total capacity.

 

There might be days here and there when you write that much but mostly I'd imagine you'd be in the single-digit GB's per day for daily use, if even that, unless you're doing something very data intensive.

 

(Third-party tests have shown that these drives generally work well beyond the warranty TBW limit, as well.  It's not like you have to throw it out if it does hit 600 TBW.)

 

Bottom line — Don't worry too much about your SSD drive health with regards to writes unless you're doing something extreme.  It does have a limited number of writes, but that number is still so high that you're unlikely to reach it during the drive's practical lifetime.

 

Not to say that SSDs can't fail...  It's just not often from "hitting the write limit" (in my experience).  Have a backup strategy for any important data.

 

Rule of thumb for me is at least 10% free space (unless maybe it is a very large drive, then perhaps less than 10%).  That's more because I don't want to be worried about running out of space by surprise/accident than because of performance considerations, but having the drive not being completely full can help the SSD do its thing (garbage collection / wear leveling / etc.) more effectively.

[RandomIdiot]

Does this mean that we can disregard the advice of not using hibernate on a SSD based device? I'm really getting PO'd with this modern standby garbage that is being pushed and since S3 sleep is not an option (thanks Lenovo), hibernate might be my only choice

 

[Aaron44126]

I think that's dated advice from when SSDs were smaller and TBWs were less.  Hibernate away.

[RandomIdiot]

You're probably right. I first got that advice back when I was using a whopping 128GB msata drive in my old Acer Nitro

[Etern4l]

On 10/14/2022 at 4:05 PM, Aaron44126 said:

Think about how high the warranty TBW value is and how long you might want to use the drive.

 

Let's look at, for example, Samsung 980 Pro.  The 1TB version is 600 TBW for warranty purposes.  Samsung is confident that you can write 600 TB to the drive to the point that they will replace it for you if it fails before then.

 

Let's say you think you might keep it for five years (which happens to be the warranty period).  600 TBW ÷1825 days = 336 GB per day you would have to write to the drive to hit the TBW limit before the five-year warranty is up, or about one third of the drive's total capacity.

 

There might be days here and there when you write that much but mostly I'd imagine you'd be in the single-digit GB's per day for daily use, if even that, unless you're doing something very data intensive.

 

(Third-party tests have shown that these drives generally work well beyond the warranty TBW limit, as well.  It's not like you have to throw it out if it does hit 600 TBW.)

 

Bottom line — Don't worry too much about your SSD drive health with regards to writes unless you're doing something extreme.  It does have a limited number of writes, but that number is still so high that you're unlikely to reach it during the drive's practical lifetime.

 

Not to say that SSDs can't fail...  It's just not often from "hitting the write limit" (in my experience).  Have a backup strategy for any important data.

 

Rule of thumb for me is at least 10% free space (unless maybe it is a very large drive, then perhaps less than 10%).  That's more because I don't want to be worried about running out of space by surprise/accident than because of performance considerations, but having the drive not being completely full can help the SSD do its thing (garbage collection / wear leveling / etc.) more effectively.

 

That's how I got caught out by Samsung's meager TBW. 30GB/day is not necessarily that much. Actually it works out to around... 340KB/s. Then I woke up with 100 TB written in a month lol. For light I/O use, gaming etc. people can rest assured their Samsung SSDs will hold up, otherwise it helps to actually spend a moment to estimate TBW based on projected usage. 

 

Frequent hibernation of a 32GB machine doesn't seem to be a problem, I've done it for years. Would be interesting to know why, a very fast compression algorithm is probably involved. 

[Aaron44126]

The figure I gave, 336 GB per day, works out to about 4 MB/s. Maybe you’d hit this consistently if you were running a DVR or camera monitoring system or something? For most workloads, I think reads would be way more common than writes and there’s no reason someone would be writing MB/s amounts of data, consistently forever.

 

If you do find yourself worried about it, you can raise the TBW by getting more/bigger SSDs.

 

Microsoft does compress data going to the hibernate file, and they also throw out anything not required (I.e. cached files from disk stored in RAM).

[jaybee83]

3 hours ago, Etern4l said:

 

That's how I got caught out by Samsung's meager TBW. 30GB/day is not necessarily that much. Actually it works out to around... 340KB/s. Then I woke up with 100 TB written in a month lol. For light I/O use, gaming etc. people can rest assured their Samsung SSDs will hold up, otherwise it helps to actually spend a moment to estimate TBW based on projected usage. 

 

Frequent hibernation of a 32GB machine doesn't seem to be a problem, I've done it for years. Would be interesting to know why, a very fast compression algorithm is probably involved. 

this is only an issue if ure worried about official warranty. if u just go by actual reliability, rest assured ur samsung ssd will have closer to like an order of magnitude higher TBW before it gives out on you

[Etern4l]

3 hours ago, Aaron44126 said:

The figure I gave, 336 GB per day, works out to about 4 MB/s. Maybe you’d hit this consistently if you were running a DVR or camera monitoring system or something? For most workloads, I think reads would be way more common than writes and there’s no reason someone would be writing MB/s amounts of data, consistently forever.

 

If you do find yourself worried about it, you can raise the TBW by getting more/bigger SSDs.

 

Microsoft does compress data going to the hibernate file, and they also throw out anything not required (I.e. cached files from disk stored in RAM).

 

Haha, sorry, teaches me for responding on the phone without glasses. 4MB/s is more respectable but still peanuts in many cases, and gosh forbid you start swapping - you'll go through that Samsung TBW allowance like a hot knife through butter. I guess what I'm saying is that it would be nice if Samsung could up this, as least on the Pro models. Alas, still 600TBW per 1TB on the 990 Pro.

[jaybee83]

19 minutes ago, Etern4l said:

 

Haha, sorry, teaches me for responding on the phone without glasses. 4MB/s is more respectable but still peanuts in many cases, and gosh forbid you start swapping - you'll go through that Samsung TBW allowance like a hot knife through butter. I guess what I'm saying is that it would be nice if Samsung could up this, as least on the Pro models. Alas, still 600TBW per 1TB on the 990 Pro.

is the 990 pro out yet anywhere? last ive seen was like a january release (planned). 

[Etern4l]

5 minutes ago, jaybee83 said:

is the 990 pro out yet anywhere? last ive seen was like a january release (planned). 

Dunno, but they've published the specs.

[Aaron44126]

Samsung’s site is saying I could buy a 990 Pro and get it December 5.

https://www.samsung.com/us/computing/memory-storage/solid-state-drives/990-pro-pcie-4-0-nvme-ssd-2tb-mz-v9p2t0b-am/