Solid state disk (SSD) has grabbed a lot of attention lately, but analysts say it’s still a niche technology that is specialized, high-priced and far from ready to supplant the bedrock that is hard disk drives. But with the promise of rocket I/O performance, some users are ignoring the cost and plopping down the big bucks anyways. For example, Danish jewelry and accessory manufacturer Pilgrim a|s was able to solve major database user response time issues by installing 64GB of flash memory from Texas Memory Systems Inc. The flash memory gave the company a twentyfold improvement in IOPS — from 1,200 I/O-per second with its old system to 24,000 I/O-per second — with the RamSan-400 appliance from Texas Memory Systems. A RamSan SSD system with 64GB of flash retails for US$72,000.
Pilgrim uses Microsoft Corp.’s Dynamics AX (formerly Microsoft Axapta) with Microsoft SQL Server 2005 Enterprise for everything from manufacturing and inventory control to accounting and business intelligence. Pilgrim said the old system was bogging down because of an IBM DS4300 storage array that unable to keep up with intense, random I/O during peak business hours.
“The RamSan is amazingly easy to install, much easier than other Fibre Channel storage devices we have tested,” said Anders Schack Petersen, a sys admin for Pilgrim. Pilgrim plans to upgrade to 128GB in its RamSan SSD system over the next two years.
What most users don’t know about SSD relates to how versions based on non-volatile NAND flash memory are increasingly finding their way into laptops and PCs, and how Microsoft Vista compatibility with the emerging technology is expected to give a major boost to hybrid hard disk drives, which combine spinning disk with SSD (see “New hybrid drives promise faster Vista laptops, PCs, servers”).
Today, most SSD is actually manufactured with volatile, CMOS RAM-based components and built-in battery backup providing huge, 4X and even 10X performance improvements for companies that live or die based on their ability to perform high-speed database transactions. John Rydning, research manager for hard disk drives at IDC in Framingham, Mass., recently co-authored a study entitled “Solid State Disks: Is Future Disruption on the Horizon?
“Although he acknowledges the benefits SSDs are offering to a very limited user audience, Rydning also says there are some caveats on the subject of their high-end performance.
“There are a certain percentage of files that need very fast access. Anywhere from one to five percent of all files for a given server application represent a large percentage of all the I/O activity. Those are the files that are suitable for SSD storage,” he says.
With data center capacity requirements are growing at a rate of 50 percent a year, Rydning points out that companies are trying to meet that demand as inexpensively as possible. Expense is often what leaves SSD on the outside looking in because deploying it widely “would be just plain cost-prohibitive,” he says. “At this point in time, many SSDs are very expensive and are used mainly as server accelerators, or in rugged applications demanded by military/industrial customers.”
Rydning acknowledges that SSD is now being developed and launched for mainstream PCs, and these flash-based products will likely have quite different price-points than existing SSDs. So-called hybrid disks (flash/spinning disk) for PCs and laptops tout a 50 percent increase in boot times. “Still, on a price per GB basis, even these newer SSDs will be much higher priced than hard disk drives,” he says.
Samsung Corp. said 32GB of flash memory will likely add $700 or more to the price of a notebook. And, Sony’s UX90 ultra-mobile PC with a 16GB of flash memory drive retails for $1,805 — $343 more than a unit with a standard 30GB hard disk. SanDisk Corp. recently announced shipment of its 32GB solid state disk drive and it said end-users should expect $600 premium in laptops for the flash memory. But, there is also strong evidence to suggest that NAND memory is rapidly becoming more affordable. Toshiba Corp. recently announced it expects flash chips to be 70 percent less expensive by the end of March than they were a year ago. At the same time, NAND manufacturer Hynix Semiconductor Inc. said it expects prices to fall by one-third in the current quarter alone (see “64GB flash for $120? Say goodbye to hybrid disks”).
Microsoft’s recently released Vista platform includes a feature that allows SSD to be used in conjunction with a PC’s hard disk. Vista’s Ready Drive function enables the operating system to boot certain portions of the boot-up sequence from flash memory, which provides faster read access times than a hard disk drive, thus expediting the boot-up process. Vendors such as Samsung Corp. and SanDisk Corp. are introducing NAND flash drives for standard PCs that were previously designed for use in ruggedized versions.
Despite these low-end OS enhancements, however, it is the server-based transactional database segment where SSD is achieving eye-popping performance gains and rapid ROI.
Financial firm sees 10X performance increase
Driven by an intense in-house database application tied to rapidly changing stock market data, a financial firm in the Midwest initially responded to the need for extremely fast disk I/O by throwing faster servers and different versions of RAID at the problem. According to a senior systems engineer at the firm, which asked not to be named, when that tactic didn’t work they upped the ante by beefing up a server with 32GB of memory in an effort to create a large, virtual RAM drive. The SSD RAM was supposed to help the firm gain control of the application that tracks stocks and attempts to make calculated real-time decisions based on the flow of the market. The result was less than a success.
“It was significantly faster than what we were doing before, but it still wasn’t getting us the results we needed,” the engineer says. “We wanted more speed. I don’t know how many times we told all the vendors we were looking for raw speed.”
Given the paucity of SSD vendors, it didn’t take the financial firm long to narrow the field down to Xiotech and its Magnitude 3D 3000 SAN and the TagmaStore AMS1000 from Hitachi Data Systems. The HDS system was loaded up with read/write cache — what the engineer calls “their claim to fame,” but in the bakeoff with the Magnitude 3D 3000, the broadband-type cache wasn’t fine-tunable enough to interoperate precisely with the application.
For its part, the Magnitude 3D 3000 gained a significant advantage based on a simple capability. “With the Xiotech SAN, we could basically take these solid state disks, mount them as virtual memory sticks and refer to them via a drive letter. We could then dedicate the solid state disks to our application just like you would with any other resource,” he explains.
It didn’t hurt that the Magnitude 3D 3000 provided 10 times the performance of its predecessor as it crunched away at tables of massive text files, making queries against them and extrapolating the results against the financial firm’s proprietary requirements.
The firm currently has 4TB of raw data and 2TB of usable data in the SAN, and although there is a total of five servers dedicated to it, only the Xiotech machine is working directly with the stock tables application. The engineer defines raw data as the amount of physical space available before any RAID parity, and usable space as the amount of spac
