curt@dtix.dt.navy.mil (Welch) (05/04/90)
We are considering purchasing a Sequent S27 system to replace 3 Vax 11/780's, 2 Vax 11/750's, and 2 ISI V.20 systems. I'd like to hear opinions from Sequent owners about how they like their system, how well they perform, what type of problems you have had (with hardware, software, support from Sequent, etc.). Do any of you have any suggestions about other brands of equipment we should look into? Nothing I've seen so far gives both the price performance that Sequent can offer and its ability to scale up from a small to large system without replacing the whole computer. Also, can any of you give some estimations on how large of a Sequent system we will need? (How large is yours and how many users can use it at once.) We would like to run with a peek load of 60-100 concurrent users doing simple text editing, e-mail, and news reading. Most of these would be connecting through telnet connections. Thanks for any words of wisdom you can give me, Curt Welch curt@dtix.dt.navy.mil David Taylor Research Center (A Navy Lab) Bethesda, MD (301) 227-1428
andy@syma.sussex.ac.uk (Andy Clews) (05/04/90)
From article <1793@nems.dt.navy.mil>, by curt@dtix.dt.navy.mil (Welch): > We are considering purchasing a Sequent S27 system to replace > 3 Vax 11/780's, 2 Vax 11/750's, and 2 ISI V.20 systems. > > I'd like to hear opinions from Sequent owners about how they > like their system, how well they perform, what type of > problems you have had (with hardware, software, support > from Sequent, etc.). We have a Sequent S81 with 2.1Gb disk, 6 processors and 32Mb memory. It has performed almost flawlessly for 18 months. The response and general performance is astoundingly good. Ours is used as a host machine for programming courses, as a general Unix service and for scientific number crunching; it seems to handle all these simultaneously with consummate ease. Our license is for up to 64 concurrent users; the most users I have seen logged in so far is 45; it handled this without any problem, together with a fair number of big-memory background jobs. The only problem was that our local Ethernet seemed to struggle to cope with the interactive load (given that we have lots of other machines connected). We have had occasional problems with running out of virtual memory, (i.e. unable to start editors and suchlike), but I think this was a case of fine tuning of the system rather than a fault. Our other large machines (in the Computing Service) are 2 VAX 11/780s, a VAX 8530 and 3 MicroVAXs, all on a cluster. The Symmetry seems to outstrip them all in terms of performance, and it has had no hardware or kernel crashes at all in 18 months, which is more than can be said for the VAXes. Support from Sequent in the UK is generally good, although there is lots of room for improvement! I cannot tell you how rapidly they respond to major problems because we haven't had any. Our University Administration are shortly taking delivery of an S27 which is to replace their PDP11. I will leave them to comment further as they wish. -- Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, England JANET: andy@syma.sussex.ac.uk BITNET: andy%syma.sussex.ac.uk@uk.ac