SSD's are not expensive, they are actually cheaper when you look at the correct set of indicators. Do you buy a stock just on the price of that stock (hopefully you don't); instead you look at indicators and ratios to see the value of the company. Before you evaluate SSD's and NVM (non-volatile memory) with some Capacity and Scale Design in mind, let's look at the key indicators of cost and the value drivers that you need to convince yourself and your funding sources of why SSD's are lower cost.
First off you need to evaluate SSD on a Cost of Input and Output Operations that your workload needs to support: What the Storage Industry calls IOPS:
$/IOPS, not just $/GB is key to the evaluation of your designed solution.
A fast spinning 10K or 15K HDD can support you at about 100-200 IOPS, but an SSD will easily break the 10,000-20,000+ IOPS barrier if pushed properly. That's a 100X difference in capability while the cost of an SSD is clearly not 100 times a HDD.
Do SSD's wear out fast?
No, An Intel SSD will not wear out like old thinking may suggest. Yes NAND memory or Flash has a lifetime, it can't be written forever, but Intel SSD's last for years even at 10 full drive writes per day as with the Intel SSD Data Center S3700 Series. So a 100GB drive can support 1TB of writing within a single day for 5 full years. Cheaper models will support less drive writes (* maybe 10 or 30% of the drive capacity) per day all for a full 5 years of lifetime, but writing is rarely the dominant activity your database does. The Read to Write ratio is usually 50% to 80%.
Do SSD's save me power cycles in the Data Center?
Yes, the wattage that an SSD pulls is usually 1/3 (~5 Watts) that of a fast spinning and thermally expensive HDD (~15W). A single Intel SSD Data Center S3700 Series drive can possibly consolidate 10 or 20 fast spinning HDD (hard) drives depending on capacity and IOPS.
How do Intel SSD's change the user experience?
Through better access latency to disk which affects "time to user" can be an amazing 100x better at the hardware spec level. Even the fastest hard drives (15K SAS) need an access time in sub-10 millisecond range to start retrieving bytes, SSD's provide data access in 50-100 microseconds.
So now you have some evaluation criteria and background.
Here are the truer cost ratios summarized:
Watts used/Drive - SSD's are 3x better in general.
$/IOPS - SSD's can be 100X stronger at read and write IO load.
You might even start changing your database rows-processed key indicator to something like:
# of Rows processed per millisecond
Save money, Delight users, use Intel SSD. Think about the win-win on how to make your next database design change a truly spectacular result. The Intel SSD for Data Center are supported by HP Today!
If you want some insights that will help you figure this out, we will be at #HPDiscover from June 11-13 in Las Vegas. Attend our SSD demo in the Demo Theater on Tuesday, June 11th at 12:45pm (DT4419) and attend a business breakout session that will go into more details on Thursday, at 3:30pm San Polo 3204 (BB4352).