solomon@chaos.utexas.edu (Thomas Solomon) (05/16/91)
We are purchasing a 486/33 MHz EISA PC, and we would like to take advantage of the current crop of EISA disk interfaces. It appears as though a few companies are already offering EISA interfaces, both ESDI and SCSI. Adaptec and UltraStor appear to have cards that can handle SCSI and the new SCSI-2 standard. I have a few questions about these devices if anyone out there can be of assistance. First of all, the specifications of both of these devices look wonderful: full support for SCSI, SCSI-2 and FAST-SCSI-2 (up to 10 MBytes/s). Of course, there aren't any disks out there yet that can handle the Fast-SCSI yet (as far as I am aware), but there will be in a few months. On closer investigation, however, it appears as though UltraStor's device (24F) is not being offered currently with the fast SCSI-2 capability, although it can still handle SCSI-2 devices with transfer rates of up to 5 MBytes/s. I was told a few weeks ago, that Adaptec's card wouldn't be out until June, but a couple of days ago, I was told by a local distributor that the product is currently available. I called up Adaptec, but was unable to talk with anyone who could confirm whether or not the product that is currently available is the full implementation of the AHA-1740, or if it is limited like the UltraStor. Obviously, we are not going to get a Fast-SCSI-2 disk drive right now. Even if they were available, I doubt that we could afford one. However, it would be nice to have a controller card that could handle the Fast-SCSI in the future. This would tend to lean in Adaptec's favor. On the other hand, though, UltraStor's product is a couple hundred dollars cheaper than Adaptec's ($625, rather than $825), and UltraStor has received praise from people with whom I have spoken, especially an engineer at Austin Computer Systems who says that Adaptec charges extra for device drivers and that UltraStor's support is great (almost everyone there is an engineer). For the record, we are looking at two Seagate drives to go with the controller. The cheaper drive is the Wren-7 (ST41200N) with a rated continuous transfer rate of just under 2MBytes/s (15 Mbits/sec) and a "SCSI" interface. The other disk drive (for $1000 more) is the Elite-1 (ST41600N), with a rated continous rate of 3 MBytes/s (24 Mbits/sec) and a "SCSI-2" interface. Transfer rates are crucial for us, since we have\ an experiment that requires continuous transfers of up to 1.2 MBytes/sec in some circumstances. Even though the ST41200N is rated to be faster than that, I'm concerned that overhead from the operating system, etc., will drag that figure down. (By the way, can anyone suggest schemes to get the full performance out of these drives and interface cards?) I don't have any other specific questions here (unless anyone can tell me if the AHA-1740 is currently available in its ultimate form). I'd be interested in any comments that anyone has about what I've discussed above,though. Thanks. Tom Solomon solomon@chaos.utexas.edu