Measuring the Costs and Benefits of Flash For Your Data Center Workloads
Flash technology has been the highlight of just about every year-end summary and 2014 predictions of technologies transforming the enterprise data center. With all-flash arrays joining the portfolios of the major OEMs and achieving record benchmarks in 2013, more and more organizations are looking to employ SSDs to help accelerate growing workload demands, overcome storage bottlenecks and reduce their data center power consumption footprint.
One of the main barriers for many managers is the seemingly high cost of SSDs, as they are often priced higher per GB in comparison to spinning drives. But with performance and efficiency as the leading driver for implementing SSDs across data centers, capacity is probably not the best quantification to calculate the costs of SSDs in your environment.
Any acquisition analysis needs to consider not only cost per drive, but the entire environment and any impact these changes will have on costs of licensing, repair, management, power and hardware footprint. For example, for a high random I/O transaction application such as a Microsoft Exchange server, a single SSD could replace an array of 10 or more HDDs, resulting in a smaller footprint, higher performance, and lower licensing costs.
As you look into implementing SSDs in your environment, here are three main questions you should consider when measuring costs:
- Maintenance, Repair and Endurance – What is your experience with HDD annual failure rates and the costs for replacement and/or system downtime? SSD failure rate is much lower than HDDs, and thus are far more reliable as they are less prone to sudden mechanical failure and wear out. Nevertheless, SSDs do experience flash wear out over time. Endurance can vary greatly by manufacturer and design, and is essential to consider when making a purchasing decision.
- Power and Cooling – Understanding the costs of your cooling and power involves looking at the various elements in your architecture. HDDs require more power and cooling than SSDs due to the rotating media, swinging read/write heads, actuators and spinning motors. As we examine power density (IOPS/Watt) it’s important to take into consideration that SSDs not only require less power and generate far less heat, but you are also likely to need far fewer drives to deliver better performance.
- Cost per terabyte written ($/TBW) – Your best bet is to compare the cost vs. performance of the SSDs using cost per TB written ($/TBW). This will tell you how much you will be paying for the amount of data that you can actually write to the drive over its lifespan, and where SSD endurance plays the most important role in understanding costs for your system needs. Make sure to use metrics based on standardized tests for your overall calculation as these take in multiple factors such as workload, data pattern and steady state figures into consideration.
By looking at these three items, you should be able to get a better understanding of the costs and the benefits of implementing SSDs in your environment. I’ve also put together some additional links below that can be helpful when choosing SSDs for your environment or evaluating their costs in comparison to other available solutions:
1. Five Tips for Finding the Right SSDs When selecting an SSD for your environment, there are a variety of factors that you need to take into account if you are going to eventually choose a solution that can properly meet your needs. This article outlines five tips that will help you choose an SSD that meets the needs of your applications, makes the most of your available budget and reduces the frequency of future headaches you may have: http://www.datacenterknowledge.com/archives/2013/12/09/five-tips-finding-right-ssd/
2. TCO Calculator: The Storage Networking Industry Association (SNIA) has compiled an analysis of factors that need to be considered when comparing HDD and SSD for any given application. This downloadable calculator can help you better understand the Total Cost of Ownership (TCO) in your environment: http://www.snia.org/forums/sssi/programs/TCOcalc
3. How to Get Flash for the Price of Disk Storage In this joint webinar by SanDisk and Dell, you can learn about new Dell Storage flash-optimized solutions that are accelerating application performance for I/O intensive workloads such as OLTP, Data Warehousing and VDI, while reducing costs up to 80% when compared to other flash-optimized solution, and up to a 2x price advantage over competitive hybrid solutions: http://www.enterpriseefficiency.com/webinar.asp?webinar_id=30048
Brian has over 20 years of experience in Enterprise IT, server and storage technology.