Understanding SSD: Solid State Drives - Revision history

Benrwong: /* Understanding SSD Endurance */ clarified unit conversion in DWPD formula

2017-11-20T19:05:05Z

Understanding SSD Endurance: clarified unit conversion in DWPD formula

← Older revision		Revision as of 19:05, 20 November 2017
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	TBW tells the consumers how many terabytes can be written to the disk before it will begin to malfunction.		TBW tells the consumers how many terabytes can be written to the disk before it will begin to malfunction.
	DWPD (Drive writes per day) tells us how much of the disk can be written to everyday and still be expected to function within the warranty period. The equation is:		DWPD (Drive writes per day) tells us how much of the disk can be written to everyday and still be expected to function within the warranty period. The equation is:
	DWPD = (TBW of an SSD * 1000)/(365 days * years of warranty * capacity of ssd in GB)		DWPD = (TBW of an SSD * 1000 Gb to Tb conversion factor)/(365 days * years of warranty * capacity of ssd in GB)

	====Endurance Example====		====Endurance Example====

Benrwong: edited overprovisioning numbers

2017-11-20T19:03:36Z

edited overprovisioning numbers

← Older revision		Revision as of 19:03, 20 November 2017
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	+ Uses less power, less heat, and doesn't get affected by magnets.		+ Uses less power, less heat, and doesn't get affected by magnets.

	+ SSDs overprovision memory space for reserves to replaces memory cells that no longer work (A 512 GB drive will have 32 GBs reserved so in actuality, only ~~380~~ GB is usable).		+ SSDs overprovision memory space for reserves to replaces memory cells that no longer work (A 512 GB drive will have 32 GBs reserved so in actuality, only 480 GB is usable).
	===Understanding SSD Endurance===		===Understanding SSD Endurance===
	Though more efficient, SSDs still have a mortal time on this Earth just like HDDs. In the SSDs case, it is due to the flash memory cells becoming unable to store data.		Though more efficient, SSDs still have a mortal time on this Earth just like HDDs. In the SSDs case, it is due to the flash memory cells becoming unable to store data.

Benrwong: spacing

2017-06-16T17:14:56Z

spacing

← Older revision		Revision as of 17:14, 16 June 2017
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	This means that you can overwrite 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.		This means that you can overwrite 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.

	Samsung 850 Evo 1TB DWPD: 0.13699		Samsung 850 Evo 1TB DWPD: 0.13699 <br />
	Sandisk x300 1TB DWPD: 0.033		Sandisk x300 1TB DWPD: 0.033 <br />
	[[Category:Sysadmin]]		[[Category:Sysadmin]]

Benrwong: added dwpd's for samsung and sandisk

2017-06-15T22:45:54Z

added dwpd's for samsung and sandisk

← Older revision		Revision as of 22:45, 15 June 2017
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	This means that you can overwrite 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.		This means that you can overwrite 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.

			Samsung 850 Evo 1TB DWPD: 0.13699
			Sandisk x300 1TB DWPD: 0.033
	[[Category:Sysadmin]]		[[Category:Sysadmin]]

Benrwong at 22:42, 15 June 2017

2017-06-15T22:42:34Z

← Older revision		Revision as of 22:42, 15 June 2017
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	DWPD = 0.3288 (drive writes per day)		DWPD = 0.3288 (drive writes per day)

	This means that you can ~~write over~~ 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.		This means that you can overwrite 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.

	[[Category:Sysadmin]]		[[Category:Sysadmin]]

Benrwong: /* Endurance Example */

2017-06-15T22:41:59Z

Endurance Example

← Older revision		Revision as of 22:41, 15 June 2017
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	Say we had the Crucial MX300 SSD with a three year warranty. The datasheet found on crucial tells us that the TBW for their 1TB SSD is 360 TBW.		Say we had the Crucial MX300 SSD with a three year warranty. The datasheet found on crucial tells us that the TBW for their 1TB SSD is 360 TBW.

	That means 360 terabytes can be written to the disk before it will malfunction.		That means 360 terabytes can be written to the disk before it will begin to malfunction.

	In terms of DWPD, the SSD can be calculated using the DWPD formula above:		In terms of DWPD, the SSD can be calculated using the DWPD formula above:

Benrwong: spelling of the word 'find'

2017-06-15T22:41:11Z

spelling of the word 'find'

← Older revision		Revision as of 22:41, 15 June 2017
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	Though more efficient, SSDs still have a mortal time on this Earth just like HDDs. In the SSDs case, it is due to the flash memory cells becoming unable to store data.		Though more efficient, SSDs still have a mortal time on this Earth just like HDDs. In the SSDs case, it is due to the flash memory cells becoming unable to store data.
	Usually when researching SSDs, try to look for the stat TBW or DWPD to find the endurance of an SSD.		Usually when researching SSDs, try to look for the stat TBW or DWPD to find the endurance of an SSD.
	You can usually ~~fine~~ the TBW (Terabytes written) stat on SSD datasheets from company websites.		You can usually find the TBW (Terabytes written) stat on SSD datasheets from company websites.
	TBW tells the consumers how many terabytes can be written to the disk before it will begin to malfunction.		TBW tells the consumers how many terabytes can be written to the disk before it will begin to malfunction.
	DWPD (Drive writes per day) tells us how much of the disk can be written to everyday and still be expected to function within the warranty period. The equation is:		DWPD (Drive writes per day) tells us how much of the disk can be written to everyday and still be expected to function within the warranty period. The equation is:

Benrwong at 21:14, 15 June 2017

2017-06-15T21:14:50Z

← Older revision		Revision as of 21:14, 15 June 2017
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	This means that you can write over 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.		This means that you can write over 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.

	[Category:Sysadmin]		[[Category:Sysadmin]]

Benrwong: added to sysadmin category

2017-06-15T21:14:38Z

added to sysadmin category

← Older revision		Revision as of 21:14, 15 June 2017
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	This means that you can write over 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.		This means that you can write over 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.

			[Category:Sysadmin]

Benrwong: Created page on understanding SSD stats that we encounter

2017-06-15T21:14:02Z

Created page on understanding SSD stats that we encounter

New page

The general idea: SSDs are faster and more efficient than Hard Disk Drives but also more expensive. We want to use SSDs whenever we can on machines that have lots of I/O (like web servers or databases).

===The Basic Differences between SSDs and HDDs===
+ SSDs do not have moving parts and no rotating platter. They are entirely flash memory based which is non-volatile (meaning they retain information with the power off)

+ They rely on an embedded processor/controller to perform read/writes instead of an actuator arm on HDDs.

+ A good SSD can perform read/writes around 550MB/s HDDs usually run around double digits.

+ Uses less power, less heat, and doesn't get affected by magnets.

+ SSDs overprovision memory space for reserves to replaces memory cells that no longer work (A 512 GB drive will have 32 GBs reserved so in actuality, only 380 GB is usable).
===Understanding SSD Endurance===
Though more efficient, SSDs still have a mortal time on this Earth just like HDDs. In the SSDs case, it is due to the flash memory cells becoming unable to store data.
Usually when researching SSDs, try to look for the stat TBW or DWPD to find the endurance of an SSD.
You can usually fine the TBW (Terabytes written) stat on SSD datasheets from company websites.
TBW tells the consumers how many terabytes can be written to the disk before it will begin to malfunction.
DWPD (Drive writes per day) tells us how much of the disk can be written to everyday and still be expected to function within the warranty period. The equation is:
DWPD = (TBW of an SSD * 1000)/(365 days * years of warranty * capacity of ssd in GB)

====Endurance Example====
Say we had the Crucial MX300 SSD with a three year warranty. The datasheet found on crucial tells us that the TBW for their 1TB SSD is 360 TBW.

That means 360 terabytes can be written to the disk before it will malfunction.

In terms of DWPD, the SSD can be calculated using the DWPD formula above:
DWPD = (360 TB * 1000 Gb/TB) / (365 days * 3 years * 1000 GB)
DWPD = 360,000 / 1,095,000
DWPD = 0.3288 (drive writes per day)

This means that you can write over 32.9% of the drive every day for the three year warranty period, which is equal to 329 GBs of the 1TB drive.