As SSDs become more popular and less expensive, their widespread adoption necessitates a way to compare their performance both among themselves and to that of traditional hard disk drives. This article uses a black-box model to evaluate SSD performance, with enough granularity to take into account the particularities of SSDs -- especially the slow write speed (due to slowness of erases) and slow updates (which require copying, erase, and write).
The black-box model proposed by the authors seems reasonable, especially given the differing internal structure of SSDs (and the lack of knowledge thereof due to IP). As SSDs become the norm, there will need to be a way to differentiate between them and establish their relative performance. As the article shows, the main shortfalls with SSDs are several: slow erases (and, thus, writes) and the wearing-out of the cells themselves, especially on write-intensive workloads. However, I think that instead of comparing the SSDs in this article to a 5400 rpm HDD, it would have been helpful to see how they compare to a high-end disk (15k rpm) and/or an array of HDDs in RAID. This would help identify which higher-end hardware options provide better performance (i.e., whether SSDs outperform fast disks, which they probably do, and by how much/on which operations).
That said, SSDs as they are now (or at the time of article writing) seem like an especially good choice for accelerating applications (e.g. as a cheap version of a RAM-based cache) where reliable storage is not really required. Likewise, read-intensive applications would also benefit tremendously from SSD adoption. As SSDs improve, the wear issue might become less relevant. However, the highest barrier to widespread adoption currently seems to be the price. As prices decrease, higher rates of SSD failure might simply not be relevant if they’re used in the distributed and redundant file/storage systems characteristic of cloud computing. That said, eventually phase-changing memory (PCM) will probably overtake SSDs, given their higher reliability.
The black-box model proposed by the authors seems reasonable, especially given the differing internal structure of SSDs (and the lack of knowledge thereof due to IP). As SSDs become the norm, there will need to be a way to differentiate between them and establish their relative performance. As the article shows, the main shortfalls with SSDs are several: slow erases (and, thus, writes) and the wearing-out of the cells themselves, especially on write-intensive workloads. However, I think that instead of comparing the SSDs in this article to a 5400 rpm HDD, it would have been helpful to see how they compare to a high-end disk (15k rpm) and/or an array of HDDs in RAID. This would help identify which higher-end hardware options provide better performance (i.e., whether SSDs outperform fast disks, which they probably do, and by how much/on which operations).
That said, SSDs as they are now (or at the time of article writing) seem like an especially good choice for accelerating applications (e.g. as a cheap version of a RAM-based cache) where reliable storage is not really required. Likewise, read-intensive applications would also benefit tremendously from SSD adoption. As SSDs improve, the wear issue might become less relevant. However, the highest barrier to widespread adoption currently seems to be the price. As prices decrease, higher rates of SSD failure might simply not be relevant if they’re used in the distributed and redundant file/storage systems characteristic of cloud computing. That said, eventually phase-changing memory (PCM) will probably overtake SSDs, given their higher reliability.
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