D. Allen [CGL]) (10/15/89)
Anyone have stories about the 5810 or 5820 they want to share? We are thinking of replacing our VAX8600/4.3bsd with one. We were originally thinking of getting two DS5400's, but the low disk bandwidth of the 5400's would probably upset us. On our 8600 we have 6 RA81's and 2 RA82's on three UDA50 controllers. Each controller is in its own Unibus adapter. I'm trying to decide whether to keep the disks or upgrade to RA70's or RA90's or maybe get two RA90's and use the two RA82's or... And there's the whole thing about do I really want a few big and fast disks (RA90) or a bunch of small but slower ones with more seek overlap (RA70), and should I put all four disks on the one KDB50 controller or should I really buy another, or several others... If anyone has a pointer to some DEC person who can discuss such questions intelligently, let me know. This kind of technical detail is beyond our local sales rep's expertise. And can anyone explain DEC's pricing on this thing? As I understand it, a single-cpu VAX6000 machine with the same memory and disk costs the same as or more than the DS5810, but the 5810 runs at four times the cpu speed. -- -IAN! (Ian! D. Allen) idallen@watcgl.uwaterloo.ca idallen@watcgl.waterloo.edu 129.97.128.64 Computer Graphics Lab/University of Waterloo/Ontario/Canada
grr@cbmvax.UUCP (George Robbins) (10/15/89)
In article <11917@watcgl.waterloo.edu> idallen@watcgl.waterloo.edu (Ian! D. Allen [CGL]) writes: > Anyone have stories about the 5810 or 5820 they want to share? > We are thinking of replacing our VAX8600/4.3bsd with one. > We were originally thinking of getting two DS5400's, but the low disk > bandwidth of the 5400's would probably upset us. Well, I don't have one yet, but I have an order for a 5810 pending management approval and had to go thru some of the same mental excercises. The 5400 has a fair amount of bandwidth, but loses cause it has a limit on the number of drives you can attach and there is *no* way to attach a real tape drive! (TA/TU78). > Each controller is in its own Unibus adapter. I'm trying to decide > whether to keep the disks or upgrade to RA70's or RA90's or maybe get > two RA90's and use the two RA82's or... And there's the whole thing > about do I really want a few big and fast disks (RA90) or a bunch of > small but slower ones with more seek overlap (RA70), and should I put > all four disks on the one KDB50 controller or should I really buy > another, or several others.. I opted for the configuration with 2 RA70's built in, for little root, /usr and /tmp drives and plan to pick up a used HSC50, mainly so I can share a couple of TA78's with our VMS systems. I have some of CDC Sabre 1.2 G-byte drives that I hope to attach to either the KDB50 or the HSC (whichever works better) via 3-rd party SMD adapters. The RA90's look nice but I already have the Sabre drives, also rumor has it that the KDB50 has considerably better performance than the UDA50... > And can anyone explain DEC's pricing on this thing? As I understand it, > a single-cpu VAX6000 machine with the same memory and disk costs the same > as or more than the DS5810, but the 5810 runs at four times the cpu speed. They were getting blown out of the price/performance water by the competition and splitting the price maintains margins on the captive VMS customer base... -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@uunet.uu.net Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
elgie@canisius.UUCP (Bill Elgie) (10/15/89)
In article <8190@cbmvax.UUCP>, grr@cbmvax.UUCP (George Robbins) writes: > In article <11917@watcgl.waterloo.edu> idallen@watcgl.waterloo.edu (Ian! D. Allen [CGL]) writes: > > Anyone have stories about the 5810 or 5820 they want to share? > > We were originally thinking of getting two DS5400's, but the low disk > > bandwidth of the 5400's would probably upset us. I don't know how far you took your calculations, but the difference in price between a full-blown 5400 and an equivalent 5810 is somewhat less than a 2nd 5400. > > The 5400 has a fair amount of bandwidth, but loses cause it has a limit > on the number of drives you can attach and there is *no* way to attach > a real tape drive! (TA/TU78). > The 5400 does have a "fair amount of bandwith", but really only a fraction of what is theoretically available on the 5810 (an internal BI "segment" on the main cpu board vs. XMI). greg pavlov (under borrowed account), fstrf, amherst, ny
Wherry@arkham.enet.dec.com (Brad Wherry) (10/16/89)
In article <8190@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) >have the Sabre drives, also rumor has it that the KDB50 has considerably >better performance than the UDA50... Quite simply: yes. -- brad wherry uucp ...!decwrl!starch.enet.dec.com!wherry inet wherry@starch.enet.dec.com tel 508.841.2571 (w) Ex ignorantia ad sapientiam; e luce ad tenebras.
graham@fuel.dec.com (kris graham) (10/16/89)
>DECstation 5810 or 5820
A little correction.
There are no such things as "DECstation 5810 or 5820" There are DECsystem[s] 5400
and 5800 [and 5820].
Christopher Graham
Ultrix Resource Center
New York