control@ALMSA-1.ARPA (William Martin) (09/20/85)
The following showed up in a discussion on USENET's net.news, in the context of designing a stand-alone news-system server and the economics of such an hypothetical machine. First the quote: |>From: root@bu-cs.UUCP (Barry Shein) | |[This first is a quote from earlier postings, and not by Mr. Shein.] |> I'm afraid you're grossly underestimating the CPU and disk throughput |> requirements to put netnews on a machine. 2 of our 5 outbound links, on |> a 750 used solely as a communications server (Ethernets, DMR-11s, laser |> printers, etc.), are at high speed. Guess what -- one uuxqt running rnews |> and there are no cycles left. If there are two, reading news will become |> unpleasant. Those two plus a print job will totally kill the machine. | |(* This was in response to my suggestion to commit an inexpensive box as a |usenet server at your site, possibly plus working out a faster transport |as a way to alleviate one aspect of news problems, a small one |admittedly, but one that comes up frequently *) | |I am afraid you are grossly confusing price with cpu power by posing your |750 as an example. | |It is nearly impossible to buy anything these days much slower than a 750 |for more than a few thousand dollars. | |My ~$5,000 AT&T 7300 (UNIX/SYSV) apparently will run neck and neck on |your favorite benchmarks with your $200,000 750* (I own a 750 also, |without formal benchmarks I believe the benchmarks that show this just |from using each.) And *THE POINT*: for $5,000 I can use it as an |intelligent USENET modem without much justification (I suspect you use |your 750 for much more than a usenet device.) Even if you believe my |7300 is, what, 25% slower, 40% slower, my argument still is not that |unreasonable as you seem to complain (and it ain't that much slower.) | |Wake up, you, like I, own a curious paper-weight of a past age. Sell it |to a VMS user (who doesn't have much choice) at 20c or so on the dollar and |buy something 3-5X the speed (one of the new 68020 boxes with a good winch.) |[I will, any VMS users interested? unlike a uvax, it has real periphs...] | |Obsolescence hurts, ouch! Hey, it was a fine box in its time...(vax.) | | -Barry Shein, Boston University | |*NOT floating point, but I don't think that is at issue here. [Some specifics related to the USENET news system deleted here...] OK, now my questions: 1) Is this true? (That is, is the 750 essentially an obsolete paperweight nowadays?) 2) If true, can it be fixed? Are the defects in the 750 so basic that it cannot be brought up to current standards of good performance by replacing or upgrading certain parts? If it can be, is it known if DEC has researched this and is planning to (or already does) provide a path for making the 750 perform as well as the average new machine of comparable size? (Or would this not pay well enough to be worth the effort on DEC's part, and they would put the effort into selling new machines? If so, how about other aftermarket vendors doing this?) Or would so much have to be upgraded or replaced to do this that the cost would make it uneconomic? [Note on this latter point -- to those of us under the thumb of government procurement regulations and practices, it is often far easier and simpler to buy "upgrades" or "add-ons" for existing equipment than to buy a new item, even if the cost for the former is greater. So "uneconomic" may not be the same for all of us.] Any comments on the general issue would be welcomed. Regards, Will Martin ARPA/MILNET: wmartin@almsa-1.ARPA UUCP/Usenet: seismo!brl-bmd!wmartin
sutter@osu-eddie.UUCP (Bob Sutterfield) (09/23/85)
> ... > 1) Is this true? (That is, is the 750 essentially an obsolete > paperweight nowadays?) > > 2) If true, can it be fixed? Are the defects in the 750 so basic that it > cannot be brought up to current standards of good performance by > replacing or upgrading certain parts? If it can be, is it known if DEC > has researched this and is planning to (or already does) provide a path > for making the 750 perform as well as the average new machine of > comparable size? > ... > Regards, > Will Martin > > ARPA/MILNET: wmartin@almsa-1.ARPA UUCP/Usenet: seismo!brl-bmd!wmartin There have always been rumors that the developers of the 750 were constrained by marketing considerations to slow down the CPU by inserting no-ops in the microcode. This was to keep it from being too close to the compute speed of the 780, which was a good first stab at implementing the architecture, but slower than an implementation using more current technology (witness the 785 upgrade). I once asked a DEC Field Service rep who claimed (and seemed) to know a good bit about the microcode situation, and he "unofficially" confirmed the story. If this is the case, a 750 could be pumped up to a "755" with nothing more than a new rev release of the console TU58, containing de-no-opped (is that a word?) microcode. This wouldn't, of course, make up for the paucity of buffered data paths and a slower UNIBUS (as compared to the 780), but it would certainly help. -- Human: Bob Sutterfield Facilities Management Division The Ohio State University Instruction & Research Computer Center Workplace: Ohio Cooperative Extension Service, Computer Management Group OCES VAX System Manager/Programmer (VMS) Mail: ...cbosgd!osu-eddie!sutter.UUCP or: sutter@ohio-state.CSNET or: 2120 Fyffe Rd rm 109, Columbus OH 43210 MaBell: (614) 422 - 9034