Micronics 386 motherboards

[Roger Cornelius]

>From article <22861 at cup.portal.com>, by cliffhanger at cup.portal.com (Cliff C Heyer):
- 
- For 25MHz, clock time is 40ns. For 0 wait states you 
- would have to be able to do a memory access in 40ns. The 
- fastest DRAM is 60ns, BUT if you get 4MB 4-way 
- interleaved 160ns DRAM then your cycle time would be 
- 40ns ASSUMING you are reading bytes sequentially from 
- memory. If your application does lots of random memory 
- reads, though, you'll have wait states again. (PS 
- interleaved memory is not new - computers like the 
- DECsystem-10 and 20s of the 70s used it for the same 
- reason.) If you want 0 wait states all the time, you'll 

Can you explain interleaved memory and what it's advantages are?  What
are the disadvantages of using Unix/Xenix on a non-interleaved system.
The latest PC Mag. benchmarks several 33 mhz machines, and some of the
systems had interleaved memory while others did not.

Roger
--
Roger A. Cornelius           rac at sherpa            uunet!sherpa!rac

>From vn Mon Oct  9 00:03:28 1989
Subject: Re: Micronics 386 motherboards
Newsgroups: comp.sys.ibm.pc,comp.unix.i386
References: <22861 at cup.portal.com>

>From article <22861 at cup.portal.com>, by cliffhanger at cup.portal.com (Cliff C Heyer):
- 
->2. 100ns ram, or do you prefer the 80ns ? 
- For 25MHz, clock time is 40ns. For 0 wait states you 
- would have to be able to do a memory access in 40ns. The 
- fastest DRAM is 60ns, BUT if you get 4MB 4-way 
- interleaved 160ns DRAM then your cycle time would be 
- 40ns ASSUMING you are reading bytes sequentially from 
- memory. If your application does lots of random memory 
- reads, though, you'll have wait states again. (PS 
- interleaved memory is not new - computers like the 
- DECsystem-10 and 20s of the 70s used it for the same 
- reason.) If you want 0 wait states all the time, you'll 

Can you explain interleaved memory and what it's advantages are?  What
are the disadvantages of using Unix/Xenix on a non-interleaved system.
The latest PC Mag. benchmarks several 33 mhz machines, and some of the
systems had interleaved memory while others did not.

Roger
--
Roger A. Cornelius           rac at sherpa            uunet!sherpa!rac