Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!tut.cis.ohio-state.edu!ukma!gatech!mcnc!ecsvax.uncecs.edu!dukeac!wolves!ggw From: ggw@wolves.uucp (Gregory G. Woodbury) Newsgroups: comp.arch Subject: Re: 88000 vs 3081. (long response) Summary: need for i/o bandwidth Message-ID: <1989Sep16.044013.429@wolves.uucp> Date: 16 Sep 89 04:40:13 GMT References: <21962@cup.portal.com> <1989Sep12.031453.22947@wolves.uucp> <22130@cup.portal.com> Sender: Uecsgate@uncecs.edu (Unix-to-Unix Copy) Reply-To: ggw@wolves.UUCP (Gregory G. Woodbury) Followup-To: comp.arch Organization: Wolves Den UNIX BBS Lines: 140 In article <22130@cup.portal.com> cliffhanger@cup.portal.com (Cliff C Heyer) writes: >Re: Gregory/88000 vs 3081. > >In article ggw@wolves.uucp (Gregory G. Woodbury) writes: > >>So what is a "workstation"? I have been unable to >>make any real distinction between a "workstation" and a "high-performance PC". >>The distinction (if there is one) is purely marketing hype. Please allow me to correct this: "I have been unable to find any real distinction between SOME (so called) workstations and MOST (so called) high-performance PC's." The point of my article was to second the need to scream at the manufacturers in order to get a reasonably priced but fast buss. Its too bad that the EISA consortium seems to have buckled under and died. >Ask yourself why a 1974 DECsystem-10 could support 40 users with >only 1 MIPS of processor power, and today we have PCs that have 8 MIPS (or a 1979 PDP-11/60! with even less MIPS) >but could NEVER handle 40 users with UNIX. The DECsystem-10 had a >20MB/s bus I/O BW, and had 2MB/s I/O to each of several MASSBUS >disk drives. : : >A VAXstation 3500 CPU w/box costs about $11K, and then you can >hook up all the same SCSI stuff as the IBM PC. The cost is the >same as a souped up 386, except the VAX CPU board goes for >$10K instead of $3K. So you pay a *bit* more for that 1.3MB/sec. >In fact, with the faster I/O you may get more work done with >the 4 MIPS VAX than the Clipper, because the Clipper has memory wait >states that slow it down to maybe 3 MIPS. Actually, these co-processor implementations only slow down for the i/o - all universially (seem) to have an amount of their own dedicated memory that is NOT accessed via the AT-style buss. The Clipper board have 16MB of 1 wait dynamic RAM, which combined with the dual cache controllers and large chunk prefetches, make the things scream in terms of computations, but the I/O, being bottlenecked through the AT-buss and the host CPU, still s**ks. The 88K co-processors each have 20MB of similar DRAM. In fact, it is that we NEED the most memory available that boosts the costs of these machines up into the price ranges mentioned. With the recent stabilization of the memory market, the newest machines we bought are actually a little less expensive than machines bought 2 years or so ago. >Perhaps you could try this file copy on your machine and see >what you get? no need to benchmark, the disk i/o is directly limited by the hosting AT-class machine. What it can do in DOS, is the most that the co-processor can ever get. It may be a horrible way to handle the i/o, but it does make the machine reasonably easy to design and get to market. And that is what I am objecting to! Getting the 88K as a co-processor and placing it in a "high- performance" PC host (e.g. 33MHz '386 with 11MHz buss) costs significantly less than getting the 88K workstation from DG (for example). We knew that we could effectively use the 88K, but the budgets and things are such that we can finagle a less expensive co-processor based machine several times, whereas we cannot get the money together (all at once) to get the more expensive workstation. >>We are/have been replacing our dependency on mainframe computing >>by acquiring a network of dedicated, "high performance" (and relatively) >>low cost "PC's". Some of these things are "workstations", but they all >>use the AT style PC buss, and take too bloody long to do the disk i/o. > >Yup. And that's the way companies want it (& need to have it) If they >all started to sell PCs today with 3MB/s to each disk and memory with >those *non existent* PC profit margins, no one would buy their $1M >mainframes in which case they would go broke. (hmm, there are enough people in the business that there must be some kind of profit to make. Any capitalist knows that there has to be some kind of profit there to attract all the "fish". ;-) > >If I remember, the 3081K (is it a 3081KX?) can give about 9 MIPS *per >job*, first shipped in early '82, and had an internal BW of about 70MB/s. >Your Clipper has more MIPS but no BW like 70MB/s. But the 70MB/s is >divided up to about 3MB/s per disk channel and user. Even this is vastly >faster than anything on the AT bus. (I stipulate the advantages of "mainframe" io structure and channel architecture ;-) > >>If I could have this processor (88000) in a machine with a decently >>fast bus AND at a cost nearly the same, then it would be perfect. >>...The VME bus based box would have >>cost us THREE times the cost of the co-processor configuration! > >Fast components simply cost more, and it takes more time to engineer >& test fast boards. Its the laws of physics. But once they have been designed and tested, then they should cost somewhat less to produce and price should ramp down after the bus has been around for a while. The real price-killer of the VME system we were trying to configure was the ethernet controller! NatSemi only supported one or two possible cheapernet talkers and the cost of them was way out of sight. Even being willing to do some of the integration ourselves (by getting source and kernel hacking!) could not bring the cost of the system down to the level that we were willing to really consider. >But what *you* can do is at least make sure you are getting state >of the art for your buck. This means learning facts like the Amiga's >ability to do 900KB/s DMA disk I/O, and not permitting a 33MHz 386 >to be sold with 200KB/s without writing nasty letters to the editor >of Infoworld, PC Week, etc. If you demand quality by making public the >facts, the manufacturers will be forced to at least do the best they >can. There are allot of ripoffs out there now because people have not >educated themselves sufficiently to know what not to buy. I wish >Infoworld and PC Magazine would include disk-to-disk copy benchmarks >in all their tests. (but then I have not written to them either!) > >There is allegedly some kick-ass hardware out there in 386 AT land >via SCSI/ESDI controllers ON BOARD bypassing the AT BUS. Mylex? >ALR? I'm trying to find out before I buy. ONE thing is for sure - you >can bet it won't come from IBM or DEC! They are too busy saving the BW >for their *big iron*. Yes, they (IBM and DEC - and all the rest, including DG) will save the bandwidth and fast i/o for the *big iron* machines AND the high-end "workstations". This is just what the main problem is! The marketoids and management are so concerned in keeping the distinction between certain types of machine, and they manipulate the prices in order to do so, that they miss the boat. Actually, as we research the "next" machine we are going to get, some "workstations" are actually getting a real look. We are almost at the point of deciding that we have enough compute power for the moment, and we actually need a less number-cruncher of a machine in favor of a machine that can do efficient DMA i/o and network management and maybe acting as a file server. Sorry that this is so long, but this is of extreme interest to me and some of my colleagues. -- Gregory G. Woodbury Sysop/owner Wolves Den UNIX BBS, Durham NC UUCP: ...dukcds!wolves!ggw ...dukeac!wolves!ggw [use the maps!] Domain: ggw@cds.duke.edu ggw@ac.duke.edu ggw%wolves@ac.duke.edu Phone: +1 919 493 1998 (Home) +1 919 684 6126 (Work) [The line eater is a boojum snark! ]