DOS ain't dead

With Regret, Shall Not Update UIDE /P! (Announce)

posted by Jack , Fresno, California USA, 07.05.2010, 04:55

With regret, I have decided not to implement the "memory only" UIDE cache,
for the following reasons --

A) My cache-size calculations were based on 13 bytes of data per 64K cache
block, due to using an "old" (discarded) idea. In fact, UIDE needs 14
bytes per 64K cache block. This means a 125-MB cache will take 32K of
upper/DOS memory, 250-MB will take 59K, and 511-MB will take 116K. In
my opinion, this is getting to be rather excessive!

B) A "memory only" UIDE can gain an extra 10% of speed at best, versus the
current UIDE /P cache, whose binary-search table already uses upper- or
DOS memory, and whose other 12 data bytes per cache block now take XMS.
Thus, the current UIDE /P uses only 20K of upper-memory (not 115K!) for
a 500-MB cache, and using 64K it can go up to a 1900-MB cache!

I would rather NOT "burn up" so much upper/DOS memory for only a 10% speed
improvement v.s. the current UIDE /P driver. CPU and memory chips become
faster and faster, while hard-disk and CD/DVD "access times" have remained
more constant (7200 RPM appears to be the limit for a reliable and "quiet"
hard-disk!). Faster CPU/memory chips will ultimately reduce UIDE's speed
losses when using XMS memory to insignificance. As newer hard-disks also
use 32-MB or 64-MB of "on board" cache, I begin to agree with Japheth that
modern DOS systems using such FAST hardware may NOT need a software cache,
nor in any event such large use of DOS upper-memory merely for "speed"!

So for the moment, UIDE will remain as-is, and users can choose either its
"standard" 4-GB cache with XMS for cache tables, or its slightly-faster /P
cache with a binary-search table in upper/DOS memory and a maximum caching
capacity of up to 1900-MB (not just 511-MB!).

As noted to Japheth in private E-Mail, I apologize to all for being a SLOW
thinker, and I will go on trying to think of BETTER improvements for UIDE!

---
(Account disabled on user's request.)

Complete thread:

• Need User Comment Re: Possible UIDE /P Changes! - Jack, 05.05.2010, 21:34 (Announce)
  • Need User Comment Re: Possible UIDE /P Changes! - Arjay, 05.05.2010, 23:12
    • My Thanks, Arjay! - Jack, 06.05.2010, 01:00
      • My Thanks, Arjay! - Arjay, 06.05.2010, 01:50
  • Need User Comment Re: Possible UIDE /P Changes! - Zyzzle, 05.05.2010, 23:17
    • My Thanks, Zyzzle! - Jack, 06.05.2010, 01:09
  • With Regret, Shall Not Update UIDE /P! - Jack, 07.05.2010, 04:55
    • With Regret, Shall Not Update UIDE /P! - Arjay, 07.05.2010, 21:38
      • Separate UIDE-M Driver Might Be Better! - Jack, 07.05.2010, 22:02
        • Separate UIDE-M Driver Might Be Better! - Arjay, 07.05.2010, 22:31
        • See also private message - Arjay, 07.05.2010, 23:07