I want to install a 100MHz 128 MB DIMM into a computer that already works with a 128 MB 133 MHz DIMM. What will happen? Will it just run slower?
The 100MHZ memory is from a 350 MHz P2 system. The target computer has a SiS 730S motherboard running at 1.1GHz with an AMD Duron processor.
First check your motherboard book to see if the new RAM you want to install is usable by the system.
Oh and welcome to the forums 
yeah Tech’s right without knowing the exact spec of both DIMMs and viewing your motherboard manual, it’s difficult to say, however, just plug it in and see if it works, you won’t harm anything, just remember, while your inside the system and you don’t have an anti static wrist strap just touch an exposed metal part of the case every minute or so
BTW: installing PC133 RAM with PC100 RAM does work 9 times out of 10, however, your right about the RAM slowing down, thePC133 will run at the speed of the PC100 RAM, however, with a 1.1 Duron, i doubt you’ll notice the slow down as you will also be doubling the RAM
Well, I installed it and it seems to work. Is there a test program that can look at the speed of memory? The computer generally seems to run faster.
Just some details FYI:
The motherboard manual (for an M810LR-H) isn’t available somehow, so I used the M810LMR, V1.6 manual, although I have a 7.1A version motherboard. Anyway, since the board takes 133MHz memory, its should handle 100MHz memory easily - and now I see that it does. I imagine it must run slower, of course.
I looked up the markings on the two types of chips, but it was very hard to tell if they were compatible.
yeah, PCWizard
the only identifiable marks on the DIMMs or chips will be the manufactures part numbers, & each manufacturer make up their own part numbers, so, they don’t mean anything
OK, I ran PCWizard.
I ran the RAM Benchmark and the Memory Benchmark - once for 128MB 133MHz and once for the 256MB 133/100 MHz mixed.
I didn’t see much difference at all. In fact at some block sizes the bandwidths was better with 256MB.
The bus speeds still show almost 100MHz for either memory configuration. Is there a BIOS setting I should be looking at?
no, using PC100 & PC133 together will always run at the speed of PC100 (100Mhz)