SanDisk's Netbook flash uncovered
Not great, not bad
SanDisk has revealed missing details about its pSSD gen 2 netbook flash product, showing it's not as leading edge as it seemed, but could be ideal for netbook use.
The company's main aim was not performance alone but cost. A spokesperson said it "wanted to bring as much capacity and performance as possible under or near the floor cost of an HDD".
So it is 2-bit MLC NAND and not the more capacious, but slower, 3-bit. It does not use SanDisk's much-lauded ExtremeFFS flash file system to speed up operations. However, ABL, which SanDisk already uses in its flash products helps things go faster, with the spokesperson saying: "ABL... provides approximately twice the performance of conventional NAND flash."
SanDisk decided not to use ExtremeFFS so as to achieve "the lowest possible cost and minimize the controller footprint".
Regarding I/O performance, SanDisk said: "We are still in the performance tuning stage of this product; expect more details from us closer to product release in February. However, it is clear that the pSSD Gen 2 will be faster than HDDs, a significant improvement over modular SSDs in 2008 that offered only approximately 1,000 vRPM [1000 virtual hard disk drive RPM] of performance." ('Modular' SSDs are the type used in netbooks.)
Virtual RPM is a SanDisk metric and intended to help compare SSD and HDD performance. An SSD vRPM number of 1,000 means that a hard disk drive spinning at 1,000rpm would equal the performance of that SSD. A 5,400rpm HDD would be 5.4 times faster than that SSD at random reads and writes.
The pSSD gen 2 price will be comparable to that of OEM quantities of 80GB 2.5-inch hard drives, which SanDisk says are the lowest-cost 2.5-inch HDDS available today.
When SanDisk said that the gen 2 pSSD flash drives don't sacrifice performance or reliability it had this in mind. "In netbooks in 2008, customers were forced to choose between an SSD with high reliability, but with performance that was less than an HDD [approximately 1,000 vRPM] or an HDD with relatively poor reliability but 5,400 rpm performance. The SanDisk pSSD gen 2 offers the reliability advantages of solid state drives while exceeding the performance of HDDs for the first time in this segment."
This suggests that the gen 2 pSSDs have a vRPM rating of more than 5,400.
The actual write cycle endurance numbers are being finalised but SanDisk says it has exceeded its OEMs' endurance requirements. The numbers will be available in February.
If SanDisk has built a netbook SSD product that truly outperforms a netbook hard drive while being more reliable and similarly priced, then it has made quite a leap forward. The vindication of this will come if netbook OEMs adopt the gen 2 pSSD in droves. Nary a one has spoken yet. ®
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