Written: 8/4/99
Written by:
Moto Racer®
Ram Supplied by:
AMK Services
My
rule when it came to RAM was always to have double what the average computer
had. When most computers were running 16 megs (remember those days) I had 32.
When they move to 32 megs, I went to 64, then 128. Now I notice that most high
end computers being sold by Gateway and Dell are shipping with 128 megs of ram.
As you can guess, I decided to go to 256 megs just to maintain my 2 times
standing.
I've noticed the move from 64 megs of RAM to
128 offered a nice little performance increase. The question is does going from
128 to 256 meg of RAM do anything? That's what this article will try to find
out.
First, a little explanation of how a CPU does
its stuff and why RAM is important. The CPU tries to keep it's most recently
used instructions as close to the CPU as possible so it can get at it faster.
When the CPU need instructions, it first looks for it in its L1 cache. This is
where the most recently used instructions are stored. On a Pentium III or
Celeron, it's 32K in size and runs at the same speed as the CPU. If it doesn't
find the instructions there it will produce what is known as a "cache miss".
Getting a cache miss on the L1 cache will
make the CPU proceed to the L2 cache to look for the instructions. The L2 cache
on a Pentium III is 512K in size and runs at half the speed of the CPU. On a
Celeron the L2 cache is 128K in size but it runs at the same speed as the CPU.
The full speed L2 cache of the Celeron basically washes any performance gain
that the bigger but slower cache of the Pentium III may have. If a cache miss is
produced at the L2 level, the computer will then go to your system RAM. You RAM
can range from 16 megs up to 1 gig if you're crazy enough. RAM normally runs at
66 or 100Mhz (the system bus speed).
Now if after doing all that and the
instructions are still not there, the computer will then have to go to your hard
drive to get it. If it's not on your hard drive, it would mean you have no
operating system which would mean your computer isn't going to work at all. The
hard drive is the slowest part of the computer. The main point of getting more
RAM is to keep all the needed instructions within the L1, L2 and system RAM. Any
time your comp has to go to the hard drive for instructions, you take a big
performance hit. This is sometimes referred to as hard drive thrashing.
So the more RAM the better, right? Well, to a
point. There is such a thing as going too far. It also depends on the
applications you run. Programs like PhotoShop eat RAM for breakfast, lunch and
dinner. This article will take a look at how RAM affects game performance, since
that's what really counts. Who care how fast you can scroll a MS Word document?
:-)
The RAM used for this test were Micron CAS 2
PC-100 SDRAM supplied by
AMK Services. I have tested these RAM up to 138Mhz and they work fine. The
best thing about them is that they only cost $108US ($159.99 Canadian) for a 128
meg strip. This is a lot less than SDRAM of comparable quality.
Next page: The test setup
