Frequently Asked Questions

Frequently Asked Questions

Q: What makes SanDisk SSD G3 unique?
A: The following are the main characteristics that enable SanDisk SSD G3 to shine in the crowded SSD market:

  • People: Over 20 years of experience in developing managed NAND products - the best engineers in the world
  • SSD Experience: Over 15 years as leader in providing SSDs to answer the harsh requirements of the military and aerospace
  • Algorithms & IP: Holder of a wide assortment of patents and IP, most recently ExtremeFFS; the new flash management tailored specifically to maximize performance in Computing applications, enabling as much as 100x improvement in random write speed
  • ABL NAND: Inventor of a new type of MLC NAND flash called All Bit Line (ABL) that is twice as fast and lower power than traditional MLC NAND. The G3 uses 43nm ABL MLC NAND components.
  • SanDisk Controller: In-house development of brand new controller - 9 cores, 64MB of DRAM and a 128 bit bus to the NAND

Q: What is the ExtremeFFS flash management system?
A: ExtremeFFS was developed by SanDisk to maximize random write performance. The algorithm operation is page-based, which means there is no fixed coupling between physical and logical location. When a sector of data is written, the SSD puts it where it is most convenient and efficient. ExtremeFFS incorporates a fully non-blocking architecture in which all of the NAND channels can behave independently, with some reading while others are writing and garbage collecting. Another key element of ExtremeFFS is usage-based content localization, which allows the advanced flash management system to "learn" user patterns and over time localize data to maximize the product's performance and endurance. The result is an improvement in random write performance - by up to 100 times - as well as in overall endurance.

Q: Can I trust my data to SanDisk G3?
A: SanDisk G3 SSD is significantly more reliable than a hard disk drive. It is 5 times more rugged, withstanding shock and vibrations, and its MTTF(1) (mean time to failure) is 6 times better than HDDs. The G3 SSDs provide a Longterm Data Endurance (LDE) of 160 terabytes written (TBW) for the 256GB version, sufficient for over 100 years of typical user usage.

(1) MTTF - Mean time to failure based on ongoing SanDisk reliability tests.

Q: What is Longterm Data Endurance (LDE)?
A: LDE is the first industry metric that expresses how much data can be written to an SSD in its lifespan in a simple, accurate and relevant number. The LDE specification was developed by SanDisk and submitted to JEDEC as a benchmark to enable users to compare the data endurance of SSDs from various manufacturers. Based on typical end-user activity, LDE provides the total number of data writes, expressed in terabytes written (TBW), that can be performed over the SSD lifespan. Data is written using typical PC transfer size distribution of writes, written at a constant rate over the life of the SSD and data is retained for at least 1 year upon LDE exhaustion. A typical client PC user writes 4GB/day, based on SanDisk internal measurements.

Q: What is virtual Revolutions Per Minute (vRPM)?
A: vRPM is a new metric introduced by SanDisk to enable users to compare SSD performance in client PCs with the HDD and with other SSDs. The beauty of vRPM is its simplicity. SanDisk chose to use RPM since it is a language that users understand, a defacto standard in the hard disk drive (HDD) world. However, since the SSD has no revolving parts, which cause the HDD to incur latency penalties, SanDisk modified RPM to vRPM. vRPM essentially answers the question: "How fast would you have to spin a virtual HDD to achieve the level of performance seen by an SSD in a client PC?" SanDisk's new vRPM metric results indicate that SSDs are faster than HDDs when performing random read and write operations. vRPM = 50 / ((0.5 / 4kB random read IOPS) + 0.5 / 4kB random write IOPS))

Q: I heard that SSD G3 can extend the life of old laptops, how is this so?
A: As IT budgets are being cut during this economic downturn, SanDisk is offering a way to postpone notebook replacement and the associated costs. In addition to the SATA versions, the SSD G3 will be available with a 2.5" PATA configuration to easily replace hard disks in 2006/7 laptops. The SSD G3 will dramatically improve the performance of these laptops, so much so that if you take a 2-3 year old computer that would normally be ready for retirement, and replace the tired HDD with an SSD you end up with a system that in many respects is faster than a new notebook.

Q: Which markets are appropriate for SSDs?
A: The markets first to adopt SSDs are those who can most enjoy the benefits of SSDs over HDDs. The solid state advantage of ruggedness, reliability, performance and power consumption is most evidenced in mobile computing applications.

  • The business laptop market in particular, is a prime target for SSD adoption. The SSD price point has come down so that the advantage to this market outweighs the cost premium over the HDD for a growing number of business users. The case is even stronger for SSDs in corporations, when the TCO (total cost of ownership) is taken into account, clearly justifying the investment.
  • The newly emerged Netbook market, also known as the low cost PC market, has a great fit for adopting SSD modules already today. This market is enjoying the benefits of flash already now since the cost of SSDs for this market is below the floor price of hard disk drives.

Q: As the demand for higher capacities keeps growing and the $/GB of the HDD remains better, how do you expect SSD to succeed?
A: The issue is not the cost per GB, but the cost per device. How much is a particular user willing to pay for a storage device to get a particular job done? We have learned from corporate CIOs that they are willing to pay a 10-20% premium for a laptop with an SSD. Not all users are storage hungry. Corporate users such as road warriors, for instance need capacity in the range of 64GB to 128GB to get their work done, and then are much more concerned with productivity and user experience. Flash addresses these concerns directly by offering durability, high performance and power efficiency. As the cost reduction trend of SSDs continues, SSDs will continue to be available at higher capacities to a growing population. The question is no longer if SSDs will be adopted in Computing applications, but how quickly such adoption will take place in the various sub-segments.

Q: SSDs today are being offered with MLC NAND vs. SLC (binary) NAND flash. Doesn't this compromise SSD endurance and performance?
A: Although SLC (binary) flash has advantages in the area of endurance and performance, SanDisk has proven technology to provide more than sufficient endurance for typical computing usage scenarios, and performance significantly faster then hard disk drives. It is important to note that not all MLC flash is equal. SanDisk filed the first MLC patent in 1992 and has already released 6 generations of MLC in partnership with Toshiba. In the past SanDisk has driven new product categories to proliferate faster with MLC flash providing overall system cost reduction. SanDisk is strongly positioned to do the same with SSDs for the Computing market.

Q: Why would anyone spend more money on a laptop with a solid state drive than one with a hard disk drive?
A: The benefits of flash - durability, high performance, and power efficiency - are worth their cost to mobile PC users who put a price tag on productivity, data accessibility and their personal user experience. They can't afford to lose their data or compromise their productivity when their hard drive crashes. Their laptop's speed is critical to them. Their time is literally worth money. As the price of flash continues to decline, its benefits will attract a wider audience of users.

Q: When do you expect the mainstream consumer market to endorse SSDs and how big will this market be?
A: Analysts predict that by 2013 the cost of a unit of storage will be attractive enough to interest the mass market and will be adopted instead of HDDs in 20% to 30% of client computers. By then we believe that market education of flash benefits will have penetrated from the early adopters to the mainstream.

Q: Will SSDs completely replace hard disks the way flash products replaced 35mm film and floppy disks? Or will SSDs and HDDs live side-by-side?
A: Today, we see SSDs living side by side with hard drives. Hard drives are not going to disappear anytime soon, though SSD technology has the potential to encroach on certain traditional hard drive territories at a growing rate. This is particularly true in the Computing market where flash benefits over hard disk drives are particularly relevant.

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