ssenkere@polyslo.CalPoly.EDU (Scott Senkeresty) (10/29/90)
This may sound like a silly question, but I have never quite understood the use of extra memory on your pc. Other than the fact that some applications may require extra memory to run... what use is it? Does it make your computer run any faster? And, if you wanted the extra memory to set up a ram disk, does this require any special hardware? Thanks. -- -------------------------------------------------------------------------- ssenkere@polyslo.calpoly.edu "I go to parties... some times until 4.
dlow@hpspcoi.HP.COM (Danny Low) (10/30/90)
> This may sound like a silly question, but I have never quite >understood the use of extra memory on your pc. Other than the fact >that some applications may require extra memory to run... what use >is it? Does it make your computer run any faster? And, if you wanted >the extra memory to set up a ram disk, does this require any special >hardware? Extra memory can be used for... 1. Disk caching to improve disk access. 2. Print caching to "complete" a print job faster. 3. A RAM disk. All the above require software but no additional hardware. From experience all of the above will make a significant difference in speed. Danny Low "Question Authority and the Authorities will question You" Valley of Hearts Delight, Silicon Valley HP CPCD dlow%hpspcoi@hplabs.hp.com ...!hplabs!hpspcoi!dlow
py@meadow.uucp (Peter Yeung) (10/31/90)
In article <272b5d9a.36d3@petunia.CalPoly.EDU> ssenkere@polyslo.CalPoly.EDU (Scott Senkeresty) writes: > >understood the use of extra memory on your pc. Other than the fact >that some applications may require extra memory to run... what use >is it? Does it make your computer run any faster? And, if you wanted > First, there are two types of "extra memory": (1) EXPANDED memory (EMS or LIM) which is basically a memory switching scheme mapping memory pages into unused memory space; all PC's can use this type of memory (from 8088 to 486); on an 8088 based machine, you will need special EMS memory board and on 286/386/486 based machines, this is usually emulated by software utilizing EXTENDED memory (see below) (2) EXTENDED memory is memory above 1Meg; you need a 286 or higher processor to handle extended memory; extended memory can only be addressed in protected mode Many "heavy-weight" (read memory hog) commercial programs like Lotus 123 2.x can utilize EMS to store data. While some can even put executables (e.g. TSR's) in EMS (LIM 4.0 only). There are only a few programs utilize extended memory. Usually those programs switched into protected mode such that they can run in a much larger memory space (in 286 protected mode you can address up to 16Meg). An example would be Lotus 123 3.x. Another example of using extended memory is Windows 3 which runs your regular real mode MS-DOS program in V86 mode (virtual 8086 mode). Another very popular use of both EXPANDED and EXTENDED memory is for disk cache. For example, in MS-DOS 4.x, there is a disk cache driver which can utilize both type of memories. >the extra memory to set up a ram disk, does this require any special >hardware? If you are using an 8088/6 based machine, you will need an EMS board to add the extra memory. If you have a more recently designed 286 (i.e >1Meg on the motherboard) or a 386/486 machine, then all you need to add is the extra memory (on the motherboard). If you have an older design 286 box with only 1 Meg on the motherboard, you also need something like an Intel Above board which can be configured into either EXPANDED or extended memory. No, extra memory will not make your PROCESSOR runs faster per sec. However it will enable your SYSTEM to run better (e.g. addition of disk cache, less disk swapping under Windows). Just give you an example: I used to have an XT clone with 1Meg of EMS, I configured it to have a disk cache of 768K; when I was in an edit/compile cycle, subsequent compiles ran a lot faster since most of the compiler/files were already in the disk cache. -- Peter Yeung Amdahl Canada Ltd., Software Development Center 2000 Argentia Road, Plaza 2, Suite 300 Mississauga, Ont. L5N 1V8 Phone: (416) 542-6300 Fax: (416) 858-2233
felixc@cbnewsj.att.com (felix.cabral) (11/01/90)
Ok, I have a 286 with one meg of base memory and 4 megs of extended
memory. However, a lot of programs still can't access the extended
memory. The "mem" command shows only the 640k base memory which is
available for applications. I know why it does that but can I use
some sort of driver to fool the system into using my extended memory
as application segments? Is there such a beast out there?
Note I said extended memory. I don't have expanded memory so forget
about LIM or is it EMS?
I have Windows 3.0 and it doesn't use the extended memory for
applications as far as I know. I dont think I can run in 386 mode
under windows to allow acces to my extended area. Can I?
I hate to think all that memory will be used only for RAM's or cache
and not applications.
--
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AT&T Bell Labs { att!mtgzz!felixc } wave, a rad board and
Middletown,NJ { (201)957-5081 } a company sick day"