SOMETIMES IT PAYS to wait. For National Westminster Bancorp, Jersey City, N.J., patience was the preferred course in 1990, when the company was considering upgrading its mainframe data storage systems.
According to Harry DeHaven, a senior vice president, the bank's existing mix of direct access storage devices from International Business Machines Corp. and Hitachi Data Systems Corp. was rapidly reaching capacity. The devices also were cramping Natwest's data center in Melville, N.Y.
"We were looking forward and were not sure what we were going to purchase," said Mr. DeHaven. "We had to decide if we were going to go with new IBM technology or if were going to wait," he continued.
Market conditions were responsible for much of Natwest's uncertainty. Both IBM and Hitachi had been steadily improving the price and performance of the devices. But a new type of mainframe storage, based on groups of smaller, less-expensive disk drives, also was on the horizon.
Moving to the next generation of IBM storage would have forced Natwest to "make a substantial change in database geometry and perform an awful lot of work," Mr. DeHaven said. Natwest also realized that if it went with IBM it would have had to change the way it allocated and defined its data.
"In the short run it would have been a good solution but in the long run it would have been a costly situation and double the amount of work," he said.
As the $23 billion-asset bank has 260 branches and 330 automated teller machines in New York and New Jersey, plus significant commercial business, any change to storage requirements is obviously substantial.
With that in mind, management waited until 1992 before earmarking part of the more than $2 million it spends annually on hardware upgrades for storage based on the new technology, known as disk arrays, to replace the IBM devices.
According to Mr. DeHaven, before the bank made the decision to purchase Symmetrix disk arrays from EMC Corp., Hopkinton, Mass., it spent considerable time figuring out how much each megabyte would cost and how each would fit into the bank's storage hierarchy.
The cost of purchasing the Symmetrix systems in 1992 was half the cost of purchasing the equivalent technology the bank reviewed in 1990.
Mr. DeHaven said the Symmetrix units seemed to be the answer to its need to increase disk space and conserve floor space.
The advantages to using a disk array as opposed to DASD include superior performance, lower power consumption, higher reliability, and a smaller footprint, according Dr. Efrem G. Mallach, an associate professor of Information Systems at the University of Massachusetts in Lowell.
"The problem is that the technology is complicated and people do not feel enormously comfortable with it because it does not come from the largest computer maker in the world," Dr. Mallach said.
The machines Natwest purchased include three model 4832-2 units and one model 5500-3056. The 4832-2s have 60 gigabytes of storage space while the 5500-3056 has 105 gigabytes. A gigabyte is equal to roughly one million typewritten pages of data.
The units support "a piece of every application the bank runs," said William Nicholson, a Natwest assistant vice president.
"Using the EMC allows us to take advantage of state-of-the-art technology, save enormous amounts of floor space, and allows us to migrate to new new technology when and if we need to," said Mr. DeHaven.
The Symmetrix units occupy roughly one-tenth the floor space of the IBM 3380s. The bank is still using some of the Hitachi drives. The available space has allowed the bank to install a tape silo, which was deemed a necessary component of the storage upgrade.
In addition to the cost savings, Mr. DeHaven said, the bank received another bonus from the performance of the new disk drives.
According to Mr. Nicholson, the machines have reduced the input/output response time in batch processing mode by 75%. As a result, the overall elapsed time for performing the average batch job has been reduced 24%.
The machines have also improved the input/output response time of ATMs by 92%.
The improved performance is directly related to the cache architecture of the EMC units. A cache is a series of electronic storage devices which are used to "prestage," or hold, data for quick access by the central processor. At sizes from 1 gigabyte to 4 gigabytes, the Symmetrix cache is considerably larger the 32 megabyte cache found in most direct access storage devices.
The Symmetrix systems also use intelligent algorithms to predict what data are going to be needed most. The system then stores those data in the cache. Instead of being accessed from a disk drive, the data are taken from the cache and transferred to the processor electronically, a much faster process.
"Through the use of artificial intelligence, Symmetrix can predict the next three or four pieces of data a transaction may need to be completed," said Craig Norman, a product manager at EMC. "It automatically loads all of the data needed to complete the transaction onto the cache in order to conduct the transaction."
According to Mr. Norman, Symmetrix is able to determine if the data are in cache or on the disk 55% faster then an IBM storage unit.
He adds that Symmetrix also is able to reduce on-line time by 20% to 30% because the data are in the cache 90% of the time.
The Symmetrix drives also have an internal maintenance facility which constantly monitors itself to check for errors. Should an error occur, the system uses a number of diagnostic procedures to repair the problem. An optional feature, for example, can write data from a malfunctioning disk to one that is performing normally.
Mr. DeHaven said that he believes the EMC technology will carry the bank for the next five to seven years.
"The boxes have performed better then our expectations," said Mr. DeHaven.
"On top of everything else the performance is the icing on the cake," he added
According to Mr. DeHaven, finding the Symmetrix was part of doing business. "The key to success is to make sure you buy the most efficient equipment for the lowest price," he said.
At a Glance
National Westminster Bancorp Headquarters: Jersey City, N.J. Assets: $23 billion Employees: 7,000 Hardware: IBM Corp. 600J
mainframe Amdahl Corp. 700
mainframe EMC Corp. Symmetrix
4800 and 5500 storage