rick@pcrat.UUCP (Rick Richardson) (07/26/88)
In article <4796@bigtex.uucp> james@bigtex.UUCP (James Van Artsdalen) writes: >IN article <865@altger.UUCP>, dirk@altger.UUCP (dirk) wrote: >> Does anybody out there have any suggestion how to use >> the WD1006 (RLL, 1:1) Controller under 386/ix or 386/V ? >> I found out that Interleave 6 is the fastest one, but it is >> slower than using a regular WD1003 with interleave 2. >This makes little sense to me: this is a *1:1 interleave* controller: >you should use 1:1 interleave. If the controller buffers by reading >an entire track at a time, formatting with 6:1 interleave could really >slow things down if the controller isn't smart enough to read the >sectors as they come (and I think the WD1006 might be this dumb - if >not, then your chosen interleave would be entirely irrelevant). I installed an Adaptek 2372 RLL controller under 386/ix. This controller is supposed to be 1:1. I think that the AMI BIOS even suggested that the best interleave (empirically determined) would be 1:1. The drive is a Miniscribe 6128. However, I formatted and loaded 386/ix with both 1:1 and 3:1 (the default), interleaves, and 3:1 was faster. I didn't have time to investigate further into the apparent discrepancy, like trying 2:1. It seems clear, though, that the 2372 does NOT buffer an entire track at a time, as soon as it starts seeing the sectors for that track. If it did, like James says, the interleave factor would make only a minor difference. I'd guess that Adaptek means that the 2372 is capable of 1:1 interleave on a wet day in North Dakota :-). 386/ix could have provided better support for pseudo 1:1 controllers in the disk driver itself. I'm pretty happy with the improved storage capacity, and the disk plus controller cost only $930, for about $8.50/megabyte. Still, I think that the "1:1 interleave" claim falls into the same class as "zero wait-state" -- you have to read the fine print in order to conclude that these things are really achievable in "Real World" operation. I take the blame on myself for fully investigating the zero wait state issue, but blindly believing in 1:1 interleave claims. -- Rick Richardson, PC Research, Inc. (201) 542-3734 (voice, nights) OR (201) 389-8963 (voice, days) uunet!pcrat!rick (UUCP) rick%pcrat.uucp@uunet.uu.net (INTERNET)