Checking how much memory is being utilized.

Checking how much memory is being utilized.

Post by Benjamin Greenwal » Wed, 01 Nov 1995 04:00:00



And I am now going to answer part of my own question.  I got this off of the
web.

Quote:>So, what is EDO-RAM ? Basically, it's the same as normal DRAM in practically all respects, and the
>timings selected by (any) BIOS for EDO-RAM are the same as standard DRAM timings. The
>difference is that during Read Cycles, the data continues to be driven after CAS has been removed, until
>the DRAM's Output-Enable is negated. If the chipset is informed of it, it can exploit this behavior
>during back-to-back Read Cycles to improve performance somewhat.

        It would seem too me that the only thing this would improve is the cost of a
cache miss, not actually ELIMINATING the need for a good cache.  Add to which,
without a cache in Write-Back mode, you would continuously have to write
directly back into main memory, forcing the "Output-Enable to be negated" and
negating most of the benefit of being able to make multiple reads in sequence.

        Anyone have an opinion on this?  I would be very interested to see a machine
running EDO RAM w/ a cache and one without and see a speed comparison.

                                -Ben Greenwald

 
 
 

Checking how much memory is being utilized.

Post by Andrew Miles » Mon, 06 Nov 1995 04:00:00



Quote:> now.. this is just according to *MY* motherboard book and my father's and
> several of his friends,
> They suggest that you have 128k of cache for 8 meg, 256k for 16, and 512k
> for anything OVER.

The *TYPE* of cache is just as important, and probably more!

The cheapest is direct mapped, and probably 95% of motherboards use it
(thin air figure). It is okay for DOS in a single tasking environment,
but really sucks rocks in a multitasking one.

Associative is the most expensive (so much so that only set-associative
is available it seems). It is hard to find mobos with it.

The difference in the two is that direct mapped cache is useless after
a context switch, and needs to be reloaded. (Set) associative cache
can keep more of the old context available = fewer wasted memory cycles.

Write back cache is a must too. The speed of processors today makes
it essential to keep them fed from a fast cache. The more time in cache,
the more time there is for doing slow main memory accesses concurrent
to processing.

The standard rule of computing applies: more is better.

-- Andrew E. Mileski --

-------------------------------------------------------
Dark Matter Technologies Inc. - Ottawa Ontario, Canada!


 
 
 

1. This clone thing...am I stupid, or am I right?


says...

I admire your passion, Chris..

The only issues which have kept myself from looking seriously at Linux
would be:

* It's Unix and the learning curve to start getting productive strikes me
as probably very steep

* It doesn't support plug-and-play.  If your hardware doesn't have Linux
drivers, it don't play..

* Not nearly the amount of developers out there doing stuff for Linux as
there are for Wintel.  Can I get MS Office for Linux?  Can I get
Photoshop for Linux?  Can I get QuarkXpress for Linux? etc.. a big turn
off for me.

--
Reuben King
Email: "reuben at texas dot net" (in plain english to foil spam-bots.
grrr!)

2. Installing on Gateway w/ Torisan Sanyo CD-ROM

3. First field in /etc/inittab?

4. I am with the following error, when i am running lilo...

5. Fast Movie Machine (tv card)

6. Am I touchy? Or am I right?

7. Please help with UUCP connection

8. Am I seeing IPv5, or am I hallucinating?

9. I am buying an Ultra 5 but am lost in part numbers ....

10. I am in text mode, what browser am I running....

11. I am si**y am I?

12. how do I check the version I am runnning on?