I have a motherboard that supports PC100 and PC133.
Mention of the motherboard make/model/chipset might be relevant.
I have gone to the various
memory mfg sites, but maybe I missed something. Is PC133 faster than PC100 by
33% (133/100)?
Yes, and no. PC133 is rated to be stable operating at 133MHz, PC100
rated up to 100MHz. Of course 133MHz IS faster than 100MHz, but your
motherboard chipset, bios settings, and CPU determine the actual
operating frequency, and possibly choices on whether to run the memory
at synchronous (same) speed as the FSB, or at +-33MHz, asynchronous
mode, which is often (but not always) same or lower performance even
at a higher memory bus frequency.
If I install additional PC133 will my computer gain more than
if I add PC100?
If your system is currently using PC100 memory, presumably at 100MHz
(or even at 66MHz), it will make no difference at all in performance
whether you added PC100 or PC133. The larger issue is what the
motherboard and chipset support.
Currrently I have 384 MB of PC100.
Then also consider that your motherboard may or may not be (as) stable
with all memory slots populated. Many boards must use reduced memory
timings with 3 or 4 memory slots filled, else become instable. It may
not apply to your board but is something to keep in mind as it's
pretty common.
If the answer to the above questions is
that PC 133 is faster than PC100, then will it be advantageous to change out
the PC 100 to PC133?
No, unless the motherboard has integrated video which uses that memory
as "shared" video memory and the bios allows settings a "+33"
asynchronous memory bus speed. Otherwise there is no advantage to
PC133, except that if your motherboard can accept higher-density
memory it's cheaper, and it's harder to find 256MB PC100 modules
especially at reasonable prices but as of yet we dont' even know what
motherboard you have, if it can even use higher-density memory.
If I remove the 128 MB of PC100 and replace it with 256
MB PC133 will it give a great speed increase or just a little.
If your use of the system causes the hard drive to be used as virtual
memory, to whatever extend it does that (how much real memory your
system is lacking to perform the required tasks), is the extent to
which the performance will benefit from an additional 128MB of memory.
Crucial has a memory link that said that 384 MB has higher performance than 512
MB. It was not clear what the numbers meant, but I thought that more memory
had higher performance.
Does anyone know of some useful links for advice on the above.
Thanks, Rick
What would be helpful to us:
- Motherboard make/model/chipset info
- Operating system
- Most demanding uses of the system, and any further info on how much
virtual memory (swap file or page file) is being used. A description
of types of applications/games/etc, and number of apps running
simultaneously would at least give a rough idea if exact figures
aren't easily obtainable
- How many modules comprise the current 384MB of installed memory
For the generic answer, generally it would be good to have 2, 256MB
modules installed. It's helpful for a variety of more demanding tasks
and allows a larger file cache to reduce HDD (re)access in addition to
reducing HDD virtual memory useage. On the other hand, having two
256MB modules AND a 128MB module may more likely have diminishing
return on performance or perhaps even a performance penalty (or
reduced stability). Also keep in mind that some chipsets require
registered memory for amounts over 512MB, like Intel BX chipset...
such boards will "try" to run with non-registered memory but errors
may result.
Whatever you end up doing it would be prudent to run
http://www.memtest86.com for several hours, the longer the better.
Dave
