ted@imsvax.UUCP (Ted Holden) (05/30/86)
John R. Levine of Javelin SW writes: >We have a 3com ethernet with two servers. One is a PC-AT with a 400MB >Fujitsu disk. The other is a 3server with a 70MB voice coil SCSI disk. >We're still running the old EtherShare software, but in discussions with >our pals at 3com, I gather that the relative speeds under the new 3plus >software will be similar, even though everything is sped up. >Anyway, the result is that the 3server handles disk requests almost twice >as fast. I believe that the reason is twofold. The 3server has a good >ether interface with reasonable buffering, while the AT has the usual 3com >card with only one packet buffer. The other reason is that the 3server has >more memory and an architecture designed for I/O bandwidth. Let me apologize apriori for seeming to have put out a request for info or opinions and then wishing to argue against the first response to that request on usenet. This is one of these topics in which it's hard to know what's going on and opinions run both ways; I appreciate Mr. Levines comments. Several weeks ago I put out a request on net.micro.pc for info or opinions regarding LAN servers, and have been asking the same and one or two related questions of other sources as well. The concensus of opinion seems to be that the 3-server was the best choice about 2 years ago but is no longer competitive for a number of reasons. There are better options for a good deal less money and fewer hassles. Stock IBM ATs wouldn't get it as file servers, but the concensus choice seems to be the little Sperry-Mitsubishi IT which runs at 8 mh with no wait states and comes with a 25 ms, 44 meg disk (the 3-servers disk is 30 ms) at a local quantity-one price of around $3000. Mitsubishi produces more of these than Sperry can sell and they mostly get unloaded to small dealers. This machine, stock, outperforms the 3-server on Lans, but some locals prefer to use the Core 15 ms 300 meg disks (about $3500), which still comes in less expensive than the 3-server, and vaporizes its (the 3-servers) performance. As with all Mitsubishi products, overall quality of the little IT is very high. There are considerations aside from cost/performance which mediate in favor of the IT as well. A 3-server lives in its own little software/hardware world which is marginally if at all compatible with anything else on the planet. Aside from parts costing more, someone is going to have to stay on top of 3-server software, aside from worrying about network software. And it locks you out of the MS-DOS peripheral market and new developments. One key element in LAN performance is memory and disk-caching techniques on servers. The 3-server is an 8186 device, limited to DOS and 640K memory as I understand it. An AT can run with quite a lot more memory than that, and Novell network software can use all of it. People I've spoken to from the Pheonix-ACT-Ashton-Tate group talk about using servers with 4 to 8 meg of RAM (30 users) like it's a common thing, and I assume that this factor alone would make for a sizeable difference between the IT and the 3-servers performance, all other factors being equal. Novell seems to be a good name to keep in mind when dealing with LAN software. At least one of their systems amounts to a home-spun superset of DOS which runs an AT (or IT) in protected mode, can fully utilize a 300 meg disk such as the Core, without dividing it into 32 meg pieces, and generally has everything possible with todays technology. One final thing I would recommend for people who think BIG (and whose last name isn't Rockafeller) is the little ISI optical disk, available for $2500 - $3000 depending on quantities. This little gem uses $100 disks which look exactly like a stereo CD, hold 256 meg of data, and the device has a track to track seek time of 1 ms. The thing is a TON faster than any kind of magnetic disk I've ever seen on micros, and could be used in LANs and in conjunction with LAN dbase packages if someone put their mind to it i.e. since the thing is WORM technology, you would have to design a dbase package which wrote individual records rather than replaced an entire 10 meg dbase file when someone replaced or changed one record. The ISI disk is carried in the MD-Va. area by Image Data (Bill Blivens) at: Image Data Systems Inc. 1850 Centennial Park Drive Reston, Va 22091 703 521-9694 Naturally, an AT (or IT) could use such an animal; the 3-server can't. One final consideration: for LAN users who avail themselves of the IT as a server, next years act is obviously one of the 386 devices currently being worked on by Convergent Tech et. al. What is next years act for 3-Com? Ted Holden, IMS
bc@cyb-eng.UUCP (Bill Crews) (06/02/86)
> Stock IBM ATs wouldn't get it as file servers, but the concensus choice seems > to be the little Sperry-Mitsubishi IT which runs at 8 mh with no wait states > and comes with a 25 ms, 44 meg disk (the 3-servers disk is 30 ms) at a local > quantity-one price of around $3000. > > Ted Holden, IMS One minor correction. The IT has wait states at 8MHz, as it does at 6MHz. At 7.16MHz (or something like that), it runs with no wait states, which makes it scream past the 8MHz setting and *any* setting on the AT. -- - bc - ..!{seismo,topaz,gatech,nbires,ihnp4}!ut-sally!cyb-eng!bc (512) 835-2266