Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!usc!apple!altos!altos86!ti From: ti@altos86.Altos.COM (Ti Kan) Newsgroups: comp.unix.i386 Subject: Re: Altos 5000 Message-ID: <3854@altos86.Altos.COM> Date: 24 Aug 90 18:18:05 GMT References: <1990Aug16.174514.2646@NCoast.ORG> <15759@bfmny0.BFM.COM> <3848@altos86.Altos.COM> <1990Aug22.171700.23382@ico.isc.com> Reply-To: ti@altos86.UUCP (Ti Kan) Organization: Altos Computer Systems, San Jose, CA Lines: 68 In article <1990Aug22.171700.23382@ico.isc.com> rcd@ico.isc.com (Dick Dunn) writes: >ti@altos86.Altos.COM (Ti Kan) responds to a flame-ette from Foulk about the >> with a "standard" SCO driver can support such a requirement?... > >This is nonsense. "Supporting" a user is very much more than allowing a >terminal to be plugged in. Quite simply put, it doesn't matter whether you >can handle the I/O connections or even the I/O bandwidth; you don't have >the CPU power to support 200 people actually *using* the system. Believe it or not, we have actually tested our System 5000 running 200 users (mixed applications, consisting of Informix database, Uniplex word processor, and various others) via our automated MTS (Multi-user test suite) with really 200 serial connections. While the performance with such a load wasn't exactly speedy, it was possible to connect 200 users to it, and is to some extent quite usable. Obviously, this requires gobs of memory (the current shipping version of the System 5000 supports 64MB maximum), and fast disks systems (not just disk or controller hardware, but highly tuned disk device drivers which we have). We know that more CPU power is necessary for a large system, thus new systems with more CPU power, more memory, and more disk performance is in the works, including multi-processor systems. The point is that we have anticipated a need for high performance I/O subsystems in a large UNIX implementation, and this requires not only speedy hardware, but highly-tuned software designed to squeeze every bit of performance out of them. You are *not* going to get that with any "generic" 386 UNIX products (SCO, Interactive, et. al.) which were designed to run on some "generic" PC hardware. Moreover, companies like SCO and Interactive can't possibly provide the kind of software reliability that we could, given that we has so finely-tuned our software specifically for our hardware platform. In addition to performance tuning, We exhaustively test our software on our hardware platform, and fixed many, many bugs that exists on other 386 UNIX implementations. A vanilla SCO UNIX release and an XYZ PC combination would never pass our strict QA standards. The fact that SCO UNIX-compatible device drivers and application can drop-in shrink wrapped, and other PC-class expansion boards can plug-n-play in an Altos 5000 is simply bonus that you don't get with proprietary hardware/software vendors like Sun, Pyramid, DEC, etc. >Disk striping is truly useful, but disk mirroring is mostly a pawn in the >feature game. It takes substantially more I/O bandwidth to do the double >output, and it doubles the cost of disk storage. Why not spend only a few >bucks extra and buy reliable disks? What do you mean by reliable disks? Any hardware can fail, no matter how well built it is. While tape backups are essential, disk mirroring allows the system to *stay up* in the event one of the mirrored drives fail. This is fault-resiliency that many installations are willing to pay for. I realize that disk mirroring is expensive, but for certain applications it is worth it. Again, the original point of the discussion was the question why one would choose a box like the Altos 5000 with standard EISA bus and 486 CPU, but with special expansion I/O cards and special UNIX release, over a generic PC with SCO or Interactive UNIX. I think I have made my argument pretty clear. -Ti -- Ti Kan \\\ vorsprung durch technik! \\\ Internet: ti@altos.com /// \\\ UUCP: ...!{sun|sco|pyramid|amdahl|uunet}!altos!ti ////////\