SSD Optimizer. White Paper. October 28, Preliminary. Apacer Technology Inc. 9/F, No. 100, Hsin Tai Wu Rd., Hsichih, Taipei Hsien 221, Taiwan

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1 SSD Optimizer White Paper October 28, 2008 Preliminary Apacer Technology Inc. 9/F, No. 100, Hsin Tai Wu Rd., Hsichih, Taipei Hsien 221, Taiwan Tel: Fax:

2 SSD Optimizer Abstract When used as the primary storage medium in place of conventional Hard Disk Drives (HDD), Solid State Drives (SSD) have several concerns that have to be aware of; specifically regarding the phenomenon of fragmentation. File systems nowadays have been designed with HDDs, and do not properly develop along with SSD technology, which results in the negative impact on mass market adoption of NAND Flash memory into the consumer, small/medium businesses, and enterprise markets where legacy file systems, designed for HDDs, will remain the dominance for many years. Fragmentation is a natural side effect that will occur and accumulate with all file systems in their lifespan. As free space becomes progressively fragmented, performance of the drive will decline and superfluous write activity will increase, which diminishes the device s longevity. With typical daily operation, the optimal performance benchmark of computer systems shipping with solid state storage devices will not be sustained. Quality or design of the hardware has not much do with this fact, but file systems do. 1

3 A better defragmentation for Solid State Drives: SSD Optimizer NTFS, the most common file system in the Windows series operating systems, when not maintained, is shown to fragment free space intuitively over a few months and then grows slowly thereafter as illustrated in figure 1. Figure 1: Accumulation of free space fragmentation through normal system use. The major concern is the degradation of throughput resulting from free space fragmentation. Write performance decreases proportionately as free space fragmentation moderately to heavily increases. Small free spaces scattered throughout a volume cause the file system to write a file in fragments to those small free spaces, which will degrade the performance in writing as much as 80% to solid state storage devices. While a brand new SSD device may offer the performance in writing up to 80 MB/s range to initialize, after weeks of use, throughput will drastically deteriorate to 35 MB/s. Over a few months, write speed becomes dreadfully slow at 10 MB/s. This issue originates with how an operating system designed with no forethought to interact with the storage hardware and brought up the effect of free space fragmentation and its unique impact on SSD. 2

4 Figure 2: Write I/O throughput degradation by the phenomenon of fragmentation on free space SSD optimizer delivers automatic maintenance of the file system, keeping a low level of free space fragmentation through precise optimization techniques which preemptively force the file system not to write randomly but sequentially, and avoiding the expense of wearing out that comes with the nature of limited erase-write cycles on SSD devices. Below bar charts depicted the test configuration with free space fragmentation in a range as expected around 6 months of typical system use. The result on an Apacer 8GB SATA SSD device records performance improvements of 5.9x faster reads, 19.5 faster writes, 3.9 faster random reads, and 9.0 faster random writes than the one without SSD Optimize equipped; on the other hand, the result on an Apacer 8GB PATA SSD device records performance improvements of 3.1x faster reads, 22.1 faster writes, 2.8 faster random reads, and 8.9 faster random writes than the one without SSD Optimizer equipped. In brief, this technology amazingly ameliorates SSD performance in the long run. 3

5 W/O SSD Optimizer W/ SSD Optimizer Figure 3: Benchmark scores on Apacer 8GB SATA SSD with and without SSD Optimizer W/O SSD Optimizer W/ SSD Optimizer Figure 4: Benchmark scores on Apacer 8GB PATA SSD with and without SSD Optimizer 4

6 NAND flash drives have limited erase-write cycles in nature, which mandates that any optimization program that may seek to increase performance cannot stand the expense of wearing out the drive faster. Adapting proprietary measures to score the erase-write activity from various actions, SSDLife was used to measure the average erase-write activity on the Apacer SSD device from various actions. 35 SSDLife Erase Count RAW Average Cumulative Erase Count Stage 1. Format SSD Stage 2. Fragment Free Space Stage 3. HDBENCH Stage 4. Format SSD Stage 5. Fragment Free Space Stage 6. Hyper-Flash Stage 7. HDBENCH Figure 5: Cumulative Erase activity on Apacer 8GB PATA SSD as measured by SSDlife Starting from a freshly Windows formatted drive (stage 1), fragmenting the free space (stage 2) generates a score of 10 from SSDLife s proprietary scoring system. Then running the HDBench program (stage 3), which creates and reads files to measure hardware performance, generated a count of 4. A reformat (stage 4) incurred no change. A second run of the free space fragmentation routine (stage 5) averaged an Erase count of 9. SSD Optimizer was then run (stage 6) to optimize the SSD. It created Erase activity at an average count of 4 (identical to HDBench in stage 3). 5

7 HDBench was then run on the optimized SSD (stage 7), and this time only incurred an average Erase count of 1. This test indicates that, though the techniques employed by SSD Optimizer do incur the occasional increase in erase-write activity, the result of its operation reduces the erase write activity of typical day to day use of the SSD, thereby increasing the durability. Conclusion By no means should any other solution by distinguished competitors outperform Apacer s SSD with SSD Optimizer, but users of Apacer solutions will experience a marvelous resolution that will be maintained for the full, extended life of the storage device. 6

8 Revision History Revision Date Description Remark 0.1 October 16, 2008 Preliminary 0.2 October 22, 2008 Updated figures 0.3 October 28, 2008 Updated cover page Apacer Technology Inc. 9/F, No. 100, Hsin Tai Wu Rd. Hsichih, Taipei County 221, Taiwan Tel: Fax: Copyright 2008 Apacer Technology Inc. All Rights Reserved. Information in this document is subject to change without prior notice. Apacer and the Apacer logo are trademarks or registered trademarks of Apacer Technology Inc. Other brands, names, trademarks or registered trademarks may be claimed as the property of their respective owners. 7