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- Newsgroups: comp.os.os2.misc
- Path: sparky!uunet!sybus.sybus.com!myrddin!tct!det
- From: det@tct.com (Dennis Taylor)
- Subject: Re: os/2 ram drive
- Message-ID: <2A76DAE6.8438@tct.com>
- Date: Wed, 29 Jul 1992 17:52:35 GMT
- Distribution: comp
- References: <92210.133859BRYAN@wvnvm.wvnet.edu> <Bs48Dq.4F8@news.cso.uiuc.edu> <1992Jul28.215920.24741@jarvis.csri.toronto.edu>
- Organization: TC Telemanagement, Clearwater, FL
- Lines: 36
-
- In article <1992Jul28.215920.24741@jarvis.csri.toronto.edu> lemieux@eecg.toronto.edu (Guy Gerard Lemieux) writes:
- >tamu@uxh.cso.uiuc.edu (Todd Henderson) writes:
- [...quotes deleted...]
- >
- >Simple example: when compiling a small C program, most of the time is
- >spent reading and processing the OS/2 header files. If I put the header
- >files into a RAM disk, the access time is zilch. With disk caching, I
- >take a chance that my cache is not large enough AND that because I am
- >multitasking, my header files get flushed from the cache.
- >
- >Speaking of lazy writes: when I am doing heavy writing and reading
- >to a file, chances are it will be cached. If I stop writing to the file,
- >the lazy cache will timeout and then write the changes to the disk. If
- >this file is only a "temporary file", it need not be written to disk because
- >it will only be deleted soon anyways. Thus, the disk access is wasted.
- >
- So long as we use tools that use temporary files instead of large virtual
- memory arrays, we will gain performance by using a RAM disk in addition
- to the cache. I have found that despite the hype about OS/2's fantastic
- disk caching algorithms, that running a make in a DOS VDM with both lazy
- writes and even HPFS, (or real DOS with smartdrv.sys), a RAM disk is more
- effective. The FAQ even claims that disk intensive DOS APP's will run
- faster on OS/2 because of the caching. I have observed the reverse -- as
- much as a 15% penalty. I have been collecting actual data for _my_ usage,
- your mileage may vary. But please note, I'd still rather use OS/2 than
- plain DOS.
- [...]
- >
- >Personally, I would like a DYNAMIC RAM disk. As I copy files into it,
- >it grows in size (until I'm out of physical(virtual?) memory). This way
- >I never have to worry about making a SIZE setting in my CONFIG.SYS and
- >rebooting.
- >
- Here! Here!
- Dennis Taylor
-
-