As a result, just about anyone with responsibility for data storage is planning to expand their capacity to ensure that the data for which they are responsible is quickly accessed, safely stored and backed up. Inevitably, during this process, the question as to whether HDD or SSD is the best medium arises.
As one of the leading storage companies, Toshiba wanted to research this question and come up with a fact-based answer – based on the technology, performance and price points available in the market today. So, our test and evaluation laboratory set out to determine whether a 50TB – 100TB storage system with a certain need for agility (IOPS and MB/s) could be built with 60 comparatively low-priced enterprise capacity HDDs, or whether SSDs were the only viable solution to achieve the speed needed?
Also, as part of the research the lab wanted to determine the best architecture to achieve the maximum performance from HDDs, as well as considering the best way to use SSDs as an alternative.
The lab installed a total of 60 2TB 7200rpm 12GB/s SAS HDDs (Toshiba MG04SCA20EE) in a RAID10 configuration, giving a net 60TB capacity for the system. For comparison, the lab also built an SSD based system based on 8 1.6TB SATA 6GB/s SSDs in a RAID6 configuration, which cost the same as the HDD solution, but gave a total storage capacity of 9.6TB.
To synthesize the workload of a storage server for virtualized environments 16k byte blocks with random read/write through 12 jobs was assumed.
The research found that, as would perhaps be expected, the HDD RAID10 array search time was impacted by its small block size. The SSD RAID6 array performed significantly better, being some 2.5 times faster, but at the expense of providing just one sixth of the capacity for the same fiscal outlay.
However, when simulating a mixed workload utilizing a larger, 64kByte block size, the HDD array outperformed the SDD array. With a performance improvement of 1.4 times that of the SDD array, the HDD array provides more than six times the capacity for the financial investment.
So, what should IT managers be choosing for their storage for virtualization, email and mixed workload storage servers? The answer depends on whether capacity or performance is the key criteria.
To read about the full test setup and more detailed results, please download Toshiba’s latest white paper here: