SSD Cache (QCache 2.0)
 
SSD cache is a large-capacity secondary cache that uses enterprise SSD drives positioned between the RAID controller's primary DRAM memory cache and hard disk drives (HDD). SSD read cache extends the RAID controller's existing memory cache capacity and functionality by copying frequently accessed data to SSD drives, which are faster than HDDs, therefore boosting system-wide performance. However, SSD write cahce buffers write I/O to imporve overall IOPS. QCache 2.0 can improve random read performance by up to 18 times and reduce I/O latency by one third. SSD drives also provide a much larger, scalable cache than the memory.

QCache 2.0 supports read and write cache
1 which are up to four SSD cache pools per system. Each SSD cache pool can be used by one dedicated storage pool and its multiple volumes shared for effective usage of resources.
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Cache I/O Types
 
There are three defined cache I/O types and one customization option available which are applied to a SSD cache pool. According to your application, suitable cache I/O type would benefit the SSD running.
Improve Performance, Spend Less
 
Statistically, only a portion of data is accessed frequently in any given storage tier and requires the higher performance of an SSD. This ratio of a small amount of SSD drives balanced with many HDDs offers the best performance (price/IOPS) at the lowest cost (price/GB) with optimal power efficiency (IOPS/kWh).
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  1. SSD read-write cache function will be available in Q1 2017.
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