Re: [opensuse] SSD in openSUSE.

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smartysmart34＠web.de

23 Nov 2011 23 Nov '11

14:57

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On Wed, Nov 23, 2011 at 09:16, Hans Witvliet wrote:

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Why is everyone still perpetuating the belief that Flash based SSDs still need this careful management of write cycles? Do the math... with current SSDs and their write cycle ratings (a current/new SSD does not have a write cycle rating of 10,000 like they did 4 or 5 years ago... you are looking at 5,000,000 or more write cycles now), you would have to basically do many hundreds of GBs (or even several TB on larger drives) of writing every single day for 40 to 50 years or even more to hit the write access barriers. Everyone is basing this whole "I have to minimize write cycles" thing on SSD specs of several years ago.

I do not know where you got this info from but the opposite is the case. With shrinking structure sizes to around 25 nm (and less in the near future) the amount of write cycles dropped drastically to approximately 3.000 to 5.000 write cycles. The manufacturers often give a number called Total Bytes Written and for a current Crucial M4 this is somewhere around 72 TB. This represents 40 GB/day over 5 years. For a normal system this may still be plenty, BUT: If you have a SWAP-Partition or the pagefile on that SSD and are hibernating a 24 GB Workstation twice a day this may surely affect your SSD at some point. Regards, Martin ___________________________________________________________ SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

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C

23 Nov 23 Nov

15:38

New subject: [opensuse] SSD in openSUSE.

On Wed, Nov 23, 2011 at 15:57, wrote:

...

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On Wed, Nov 23, 2011 at 09:16, Hans Witvliet wrote:

...
Why is everyone still perpetuating the belief that Flash based SSDs still need this careful management of write cycles? Do the math... with current SSDs and their write cycle ratings (a current/new SSD does not have a write cycle rating of 10,000 like they did 4 or 5 years ago... you are looking at 5,000,000 or more write cycles now), you would have to basically do many hundreds of GBs (or even several TB on larger drives) of writing every single day for 40 to 50 years or even more to hit the write access barriers. Everyone is basing this whole "I have to minimize write cycles" thing on SSD specs of several years ago.

I do not know where you got this info from but the opposite is the case. With shrinking structure sizes to around 25 nm (and less in the near future) the amount of write cycles dropped drastically to approximately 3.000 to 5.000 write cycles. The manufacturers often give a number called Total Bytes Written and for a current Crucial M4 this is somewhere around 72 TB. This represents 40 GB/day over 5 years. For a normal system this may still be plenty, BUT: If you have a SWAP-Partition or the pagefile on that SSD and are hibernating a 24 GB Workstation twice a day this may surely affect your SSD at some point.

Then color me totally confused. There is SO much conflicting information. The vendors state one thing, people on blogs, forums and mailing lists state another, and none of the info stitches together neatly. I got my info from hours of digging through PDF files, spec sheets, presentations etc. Almost all of it pointed at larger not smaller write cycles in new SSD devices. I've seen a couple articles about the Crucial M4 recently (today) with the 3-5000 write cycle, but that does not corroborate with the 1-5 million write cycles I see elsewhere. Also, look at the specs of the Intel 710... how do those specs relate? (20% over provisioning, 2million hrs MTBF, 1PB of 8k writes over lifetime.. the 720 is claimed to have 36PB). Look at the data here http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.html Which interestingly states 3000 - 5000 writes... even at that, doing continuous writes, you're looking at (as you pointed out) 20 to 60 years (depending on the model) of sustained writes at an average of 10GB/day. Regardless of 5000 or 5000000 (depending on who you believe and how you calculate it) panicking about write management on an SSD is really over the top isn't it? Seriously we are looking at read/write lifetimes equal or exceeding what we see on magnetic media... Or am I totally misinterpreting and misunderstanding here? C. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Smartysmart34

22:32

New subject: [opensuse] SSD in openSUSE.

Am 23.11.2011 16:38, schrieb C:

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On Wed, Nov 23, 2011 at 15:57, smartysmart34 wrote:

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I do not know where you got this info from but the opposite is the case. With shrinking structure sizes to around 25 nm (and less in the near future) the amount of write cycles dropped drastically to approximately 3.000 to 5.000 write cycles. The manufacturers often give a number called Total Bytes Written and for a current Crucial M4 this is somewhere around 72 TB. This represents 40 GB/day over 5 years. For a normal system this may still be plenty, BUT: If you have a SWAP-Partition or the pagefile on that SSD and are hibernating a 24 GB Workstation twice a day this may surely affect your SSD at some point.

Also, look at the specs of the Intel 710... how do those specs relate? (20% over provisioning, 2million hrs MTBF, 1PB of 8k writes over lifetime.. the 720 is claimed to have 36PB).

Look at the data here http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.html Which interestingly states 3000 - 5000 writes... even at that, doing continuous writes, you're looking at (as you pointed out) 20 to 60 years (depending on the model) of sustained writes at an average of 10GB/day.

Regardless of 5000 or 5000000 (depending on who you believe and how you calculate it) panicking about write management on an SSD is really over the top isn't it? Seriously we are looking at read/write lifetimes equal or exceeding what we see on magnetic media...

First of all: The Intel SSDs 710/720 are quite slow compared to other current MLC-SSD. I assume that the electrical parameters might be different and the controller handels the chips differently. So this may lead to more durability. Second: The price is about four times that of other regular SSDs (while it still is MLCs, no SLC). So i expect the chips to meet higher quality criteria and as a consequence longer lifetime. All consumer SSDs (Crucial M4, OCZ Vertex 3 and alike) come with the same range of durability by means of TBW or write-cycles. MTBF just means nothing at all as it does not take into account the actual usage scenario. As I mentioned in my last post: For a normal system this may still be plenty (TBW of 72 TB). But hibernating a 24 GB RAM Machine twice a day may face you with a damaged SSD after about 3-4 years. For me this is just too fast to fail and therefor I try to avoid unnecessary writes to my ssd. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Roger Luedecke

22:53

New subject: [opensuse] SSD in openSUSE.

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Am 23.11.2011 16:38, schrieb C:

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...
I do not know where you got this info from but the opposite is the case. With shrinking structure sizes to around 25 nm (and less in the near future) the amount of write cycles dropped drastically to approximately 3.000 to 5.000 write cycles. The manufacturers often give a number called Total Bytes Written and for a current Crucial M4 this is somewhere around 72 TB. This represents 40 GB/day over 5 years. For a normal system this may still be plenty, BUT: If you have a SWAP-Partition or the pagefile on that SSD and are hibernating a 24 GB Workstation twice a day this may surely affect your SSD at some point.> Also, look at the specs of the Intel 710... how do those specs relate? (20% over provisioning, 2million hrs MTBF, 1PB of 8k writes over

On Wed, Nov 23, 2011 at 15:57, smartysmart34 wrote: lifetime.. the 720 is claimed to have 36PB).

Look at the data here http://www.tomshardware.com/reviews/ssd-reliability-failure-rate,2923.ht ml> Which interestingly states 3000 - 5000 writes... even at that, doing

continuous writes, you're looking at (as you pointed out) 20 to 60 years (depending on the model) of sustained writes at an average of 10GB/day.

Regardless of 5000 or 5000000 (depending on who you believe and how you calculate it) panicking about write management on an SSD is really over the top isn't it? Seriously we are looking at read/write lifetimes equal or exceeding what we see on magnetic media...

First of all: The Intel SSDs 710/720 are quite slow compared to other current MLC-SSD. I assume that the electrical parameters might be different and the controller handels the chips differently. So this may lead to more durability. Second: The price is about four times that of other regular SSDs (while it still is MLCs, no SLC). So i expect the chips to meet higher quality criteria and as a consequence longer lifetime.

All consumer SSDs (Crucial M4, OCZ Vertex 3 and alike) come with the same range of durability by means of TBW or write-cycles.

MTBF just means nothing at all as it does not take into account the actual usage scenario.

As I mentioned in my last post: For a normal system this may still be plenty (TBW of 72 TB). But hibernating a 24 GB RAM Machine twice a day may face you with a damaged SSD after about 3-4 years. For me this is just too fast to fail and therefor I try to avoid unnecessary writes to my ssd. One thing I most certainly do gather from all this, is that all the monkeying around is clearly unneccesary for the average desktop user. And it really is

On Wednesday, November 23, 2011 11:32:08 PM Smartysmart34 wrote: that user who is the primary user of an SSD. If you want some schnazziness what I could recommend plainly is using btrfs with the LZO compression... though this may not be advised on lowend netbooks that might feel the slight processing overhead. -- Roger Luedecke openSUSE Ambassador Ind. Repairs and Consulting **Looking for a C++ etc. mentor*** -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

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