D.H. Brown: NT Still Can’t Match AS/400

A new study released by D.H. Brown Associates Inc. gave the AS/400 high marks over Windows NT Server in meeting most enterprise computing needs.

In the IBM-commissioned study, D.H. Brown, a Port Chester, N.Y.-based technology research and consulting firm, evaluated the AS/400, running V4R3 of OS/400, against Windows NT Server 4.0 Enterprise Edition and concluded that even the most advanced versions of Windows NT continue to fall short in meeting many of the demands of “traditional IT users,” such as transaction processing and scheduled batch operations.

The research was not based on lab or real-world testing but on a comparison and analysis of the feature sets of both platforms, says Tony Iams, senior analyst at D.H. Brown, who authored the report. Iams said the research was completed in about two months.

The report, titled “Comparing Windows NT Server and AS/400 in the Enterprise,” stated that while AS/400 and NT environments tend to be configured differently (centralized with dumb-terminal clients vs. de-centralized with PC clients), both systems are typically deployed as departmental servers or enterprise solutions for small- and medium-sized businesses. Both also have highly-integrated environments with tightly coupled functions for providing database, messaging and Web services, as well as strong third-party application support.

“What we tried to show is that both NT and the AS/400 have similar approaches,” says Iams. “They both have a high level of integration, are easy to use, and have strong third-party vendor support. From that standpoint, they’re very similar. But if you’re considering transitioning to NT from the AS/400, you should be aware that the AS/400 still has a major advantage in reliability and scalability today. Microsoft is fixing that going forward – with Windows 2000 – but as of now, the AS/400 still has a critical advantage in reliability and scalability.”

Louise Hemond-Wilson, an IBM Certified AS/400 Professional who works in competitive analysis and marketing in IBM’s AS/400 Division, says the study was commissioned to help customers understand the strengths of AS/400 vs. NT. “There were places where we would have liked to see our ratings higher, but that’s part of the benefit of having an independent voice doing the research,” she says.

The study gives high praise to the inner design of the AS/400 over NT. Its superior kernel modularity gives it advantages in system integrity over NT. Its single-level store – treating memory and DASD as a single large address space – gives the AS/400 better storage and memory capabilities.

The D.H. Brown report concludes that the AS/400’s strong binary compatibility ensures exceptional backward compatibility for applications that NT can’t match. Its 64-bit capabilities keep it well ahead of NT, which remains a 32-bit system that can only support 64-bit storage, though NT is expected to become a 64-bit system sometime after the forthcoming Windows 2000 release.

The report says neither system handles enterprise-grade printing particularly well, but still gives the nod to the AS/400, thanks to its support for IBM’s Advanced Function Printing (AFP) protocol. AFP offers better support for high-volume customer statements, exception handling, queue management and checkpointing than Postscript, which most NT users use from their PC clients.

D.H. Brown also rated the AS/400 against NT in five key emerging requirements of enterprise computing: Reliability, Availability and Serviceability (RAS); Scalability; Internet Capabilities; PC Client Support and Enterprise Middleware. In three of the five – all but Internet Capabilities and PC Client Support – the AS/400 came out on top.

In RAS, the study gave the AS/400 points for its superior reliability. It says NT lags behind the AS/400 in “the maturity of its technology, the close integration of hardware and software, fine-grained instrumentation of system behavior, comprehensive revision control and rollback facilities, and operational robustness.”

Standalone AS/400s record more than 99.9 percent uptime, the report states. NT servers can only reach 99.9 percent through clustering, “highly limited hardware platforms,” and extensive service contracts with NT server vendors.

The AS/400 also has advantages in serviceability thanks to its more complete fault logging and predictive analysis capabilities and superior performance management and tuning tools. It also has superior remote management capabilities, which are key in managing globally distributed servers, and better security than NT, the report states.

In scalability, D.H. Brown gives the AS/400 kudos over NT for its “full 64-bit capabilities, greater and more credible SMP ranges, and more complete usage of auxiliary processors.” The report states that NT, though it has supported 64-bit storage and has run on 64-bit Alpha hardware since it first shipped in 1993, “fundamentally remains a 32-bit system that cannot access memory ranges greater than 4 GB, whereas high-end AS/400 SMP models support 12 processors and 40 GB of memory. Intel’s Xeon processor, which NT runs on, can currently be configured only in 4-way systems, the report states.

The AS/400 also makes better use of auxiliary processors, with a very large AS/400 system having more than 200 additional special-purpose I/O processors (IOPs), offloading many functions from the main AS/400 processors. The report says that NT can offload some I/O processing to PC SCSI and RAID adapters, but cannot in general support auxiliary processors because of its portability requirements – “more sophisticated use of auxiliary processors would be unique to a particular hardware platform.”

Not all the news from the report is favorable to the AS/400. NT wins out in both Internet capabilities and PC client support. But Iams says the AS/400 is still competitive in those areas. “NT is further up the curve, but the AS/400 can hold its own,” he explains.

Both AS/400 and NT feature a built-in Web server – IBM’s HTTP Server for AS/400 and Microsoft’s Internet Information Server (IIS) respectively – but NT also has a number of additional Internet tools built in such as the Internet Explorer Web browser, the FrontPage Web authoring tool and the Index Server site search tool. NT gets the nod from D.H. Brown for Web hosting scalability as well as in e-commerce service.

AS/400 and NT both have strong support for e-commerce – through IBM’s Net.Commerce and Microsoft’s Commercial Internet Systems (MCIS) respectively – and both provide effective Internet security. However, AS/400 implements many of its functions in the AS/400 Firewall option, which runs on the Integrated PC Server [Integrated Netfinity Server in V4R4], boosting protection – because of the IPCS’s isolation – and performance, since security tasks are offloaded from the main processor. Windows NT integrates many security functions directly into the base operating system, such as firewall functions and virtual private networks (VPNs). The report however does give NT the edge in VPN support.

Still there is an asterisk next to NT’s advantages in Internet capabilities. “Yes, NT has the bells and whistles attributes, but it’s not clear that Microsoft can support Internet applications at the same level of reliability and scalability as the AS/400,” Iams says.

Windows NT has a more significant advantage over the AS/400 in PC Client Support. As the report notes, "NT provides virtually ideal interoperability with PCs, since it essentially defines the PC server environment."

The report notes that the AS/400 has made great strides in PC connectivity over the years with services such as NetServer, the Operations Navigator GUI for administering OS/400 from PCs, the Operations Console GUI for accessing a graphical representation of the AS/400 front panel from PCs, and Windows Policy support, which permits an AS/400 to store the Windows policy file so that it can be downloaded to control PC functions.

Still, D.H. Brown rates AS/400 well behind NT in this area. NT can centrally integrate the NetBEUI protocol used natively by Windows clients, allowing them to connect to NT servers without modification. NT can also act as a server to unmodified Macintosh clients and features NetWare file- and print-sharing compatibility as an option to service PCs configured as NetWare clients.

IBM’s Hemond-Wilson says next month’s V4R4 release of OS/400 should make the AS/400 stronger in both areas where the report says it trails NT. V4R4 includes many enhancements for both e-commerce and graphical client support [see MIDRANGE Systems, Feb. 9, 1999]. “We feel our Internet capabilities and PC client support capabilities are much broader with the investments we made in those areas in V4R4,” Hemond-Wilson says.

The AS/400 regained the upper hand in D.H. Brown's study in the area of enterprise middleware, which the report defines as "the mechanisms for reliably supporting enterprise network applications." The report says the AS/400 boasts superior support for Java, superior directory service support and closer integration of database functions, largely since it embraces open standards better than NT does in those areas.

While the report credits the AS/400's Java Virtual Machine implementation for having "excellent performance" running under the machine interface of the system, it faults NT's JVM because of its "proprietary dependencies" on the Windows environment. The report also praises the AS/400's support for Lightweight Directory Access Protocol (LDAP) Version 2, an open standard for directory services, while deriding NT's proprietary NT Directory Service as too complex to manage in large enterprise networks.

In the area of database integration, the report notes that OS/400 supports ODBC and JDBC standards to provide connectivity between Web applications and DB2/400. Meanwhile, many NT software products still depend on their own distinct database mechanisms, the report says.

The report gives the AS/400 a strong advantage in traditional transactional processing (OLTP) over NT, but NT is better for Web-based transaction processing, largely because of the capabilities of Microsoft Transaction Server, which was built into NT Server 4.0 Enterprise Edition.

With Windows 2000 expected as early as later this year, NT is expected to narrow the gap between it and the AS/400 as it evolves to a true 64-bit operating system. But Iams cautions that it won’t happen overnight.

“We’ll see the gap closed somewhat, but not all the way, at least not right away,” he says. “From the functional standpoint, it takes a while to build up credibility. It’s not enough to just deliver robust function, it has to be proved in the field and that takes time.”

Hemond-Wilson declined to speculate on Windows 2000. But she says IBM is following a three-pronged strategy for dealing with NT. “We’re embracing PC clients, we’re co-existing with NT servers where it makes sense for our customers and we’re also aggressively competing against NT,” she says.

Microsoft representatives could not be reached for comment on the D.H. Brown report. But the report is consistent with recent research done by International Data Corp. (Framingham, Mass.).

“Our demand-side research shows that less than 2 percent of OS/400 users are replacing any instances of that software,” says Dan Kusnetzky, director of worldwide operating environments with IDC. "On the rare occasion that this software is being replaced,Unix, not Windows NT, is the most common replacement. Windows NT just is not reliable enough for this market segment."

The full D.H. Brown report can be downloaded for free from the firm’s Website at www.dhbrown.com

Stephen Swoyer contributed to this article.


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