Path: news1.ucsd.edu!ihnp4.ucsd.edu!swrinde!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!lll-winken.llnl.gov!apple.com!seeding.apple.com!user From: garryh@seeding.apple.com (Garry Hornbuckle) Newsgroups: comp.sys.mac.comm Subject: Open Transport FAQ part 7 - Performance Date: Tue, 31 Oct 1995 08:48:31 -0800 Organization: Apple Computer, Inc. Lines: 163 Message-ID: NNTP-Posting-Host: seeding.apple.com Apple Open Transport Frequently Asked Questions Part Seven - Performance Extracted from: Open Transport Background Q & A Version 1.8 (OT 1.0.8 Release) October 19, 1995 Performance Q: Is Open Transport native on Power Macintosh? Does this make networking faster? A: Open Transport is written to take advantage of the PowerPC(tm) processor - it is native code. This provides the necessary foundation for increased networking performance in the MacOS. To realize performance gains, however, it is equally important that networking applications also be accelerated for Power Macintosh, and that applications adopt the new Open Transport XTI-based programming interfaces. The built-in "backward compatibility" support for existing AppleTalk and TCP/IP applications must continue to run as 680x0 code in emulation on Power Macintosh. This protects a customer's investment in networking applications, but also obscures underlying performance increases from the native protocol implementations. (See Figure 1) Q: Will existing networking applications see any performance improvements on Open Transport? A: In most cases, no; most are written for the 680x0 processor and/or use the "classic" networking programming interfaces. On Power Macintosh - where Open Transport native protocols have the most performance potential - these emulated applications use backward compatibility interfaces (also emulated code) which will offsets the performance gains in the low level protocol handling. Even so, because of the differences in the way compatibility is provided for MacTCP vs. AppleTalk, in some cases TCP/IP users will see some performance improvements, especially when transferring large data blocks. To realize the benefits of native networking on Power Macintosh, it is critical to select Power Macintosh native applications that are Open Transport-ready. Upgrading applications software can thereby provide a significant performance enhancement. Q: Does the native code include ethernet drivers for Macintosh onboard ethernet adapters? A: PCI-bus Power Macintosh systems ship with a PowerPC native DLPI ethernet driver for built-in ethernet. Power Macintosh 6100, 7100, and 8100 models currently have 680x0-based drivers. Q: When will new or updated applications that support the native Open Transport APIs become available? A: New applications and updated versions of existing applications that are native and use Open Transport are available now. Users are urged to contact the specific third party vendor of interest for more details on their specific product release plans. Q: How much faster will native Open Transport applications be? A: Networking performance is influenced by many factors. As noted above, customers will see the highest performance networking when using Power Macintosh native applications that fully support Open Transport APIs. Performance will be greater with protocols that use larger datagram sizes - such as TCP/IP - than with AppleTalk (which has a fixed and limited datagram size). On high-speed datalinks such as fast ethernet, FDDI, and ATM, the performance of the network interface card (NIC) driver code is also a significant factor. Comparative shopping for NICs - based on price, service, reliability, and performance - will be in order. Open Transport - running on the built-in ethernet of the Power Macintosh 9500 - has been clocked at 9.3 Mbps throughput using low-level TCP/IP benchmarks. A pre-release version of a third party Open Transport-native implementation of 'NFS' protocols was benchmarked at 8.4 Mbps. Both figures approach theoretical maximum performance for 10 Mbps ethernet. AppleTalk performance is somewhat lower, with low-level benchmarking coming in at a bit over 7.5 Mbps throughput. Q: What about high-speed networking connections like fast ethernet, ATM, and FDDI? A: The Open Transport engineering team is continuing to work with NIC developers to realize high-performance DLPI drivers for high-speed datalinks. This is a cooperative effort, with work being done on both driver code and on Open Transport. We expect that high-speed datalink NIC drivers based on Open Transport v1.1 will be fully competitive with other PCI networking products. Of course, performance tuning will be an ongoing priority, as Apple intends to always offer a platform capable of industry leading network performance. Benchmarking on these datalinks, with pre-release Open Transport v1.1 is in progress. Preliminary results are very promising showing throughput greater than 90 Mbps for Open Transport/TCP over an ATM-155 implementation from Interphase, for example. Additional gains are anticipated as performance tuning continues in preparation for Open Transport 1.1. AppleTalk performance is expected to be lower than TCP/IP performance, due to various technical issues (including DDP packet size, and the ATP retry-acknowledgment algorithm). Q: Will developers ship NICs for fast datalinks based on Open Transport v1.0.x, or wait for tuning planned for v1.1? A: Each developer will make an independent decision to bring their product to market at such time as they are satisfied with the combined performance and reliability of their product with Open Transport. Several vendors are currently shipping PCI solutions for 100BaseTX, ATM, and FDDI. Contact the developer of interest for current availability information (see Developer Adoption). Open Transport and Servers Q: What role does Open Transport play for servers? A: The Open Transport architecture is designed to provide server applications - file, print, database, e-mail, directory, and other - with a foundation for higher performance and for more flexible configuration, while maintaining the historical differentiation of MacOS based servers - ease of configuration and administration. Q: How will Open Transport enhance server performance? A: Servers, as network-aware applications, gain access to the higher performance Power PC native implementation of networking protocols that Open Transport provides. To exploit this performance opportunity, server applications must be accelerated for Power Macintosh and must utilize the new Open Transport XTI APIs. Severs will also benefit through access to new high-speed PCI datalink implementations for Macintosh such as fast ethernet and ATM. Q: How will Open Transport enhance server flexibility? A: Open Transport introduces the capability of activating more than one network connection at the same time, using the same networking protocol. This capability is known as multihoming, and enables servers to support more clients, to offer greater total performance, and to increase the reliability of mission critical applications. Finally, as discussed above, Open Transport enables the development of transport independent applications. This will be especially valuable for server applications which need to be deployed in AppleTalk, or TCP/IP, or NCP/IPX, or other protocol environments. Q: Will Apple's server products such as AppleShare and PowerShare exploit Open Transport features? A: Yes. Apple server products will adopt Open Transport, and will over time exploit Open Transport features including multihoming and transport independence. Product details will be announced at a later date. Q: Are PCI-bus Power Macs with Open Transport 1.0.x recommended as application servers? A: No, not at this time. As is discussed elsewhere in this document, to meet customer expectations in regards to anticipated increases in flexibility and performance, server applications such as AppleShare and PowerShare, as well as third party server applications need to be accelerated for Power Macintosh and adopt the new Open Transport APIs. Q: When will PCI-bus Power Macintosh systems be recommended as servers? A: Apple recommends that server application developer adopt Open Transport v1.1 as the basis for new network applications development as soon as is possible within their product life cycles. As these updated versions of server software become available customers will find that the combination of PCI-bus, Power Macintosh, and Open Transport makes a great platform for flexible, high-performance network applications. ------------------------------------------------------------------- Garry Hornbuckle Product Manager, Communications & Collaboration ------------------------------------------------------------------- "If I told you that I | email garryh@seeding.apple.com spoke only for myself | applelink HORNBUCKLE1 would you believe me?" | fax (408) 974-1211 ------------------------------------------------------------------- .