PC100 or PC133 Memory

[couriers]

I was always under the impression that PC133 was better memory than PC100 but the current prices don’t support that. Is there something that should be considered when deciding between these two types of memory? The plan was to max out an older motherboard that already has 2 strips of 256mb PC100 modules but after seeing the prices I was thinking of grabbing the PC133 for the 1 open slot as well as replacing the existing 2 strips. Is it better to have 3 strips of 256mb PC100 memory or 3 strips of PC133?

Thanks in advance.

[Daimyo]

Supposedly, you can use PC133 in PC100 slots without problem. Because of this I think they produce a lot more PC133 than PC100 chips now, which makes them cheaper.

Unless you have a processor with a 133 (or multiplier of that) FSB, and a motherboard that supports that FSB speed, you won't get any improvement from 133 I think. If you did have the processor and MB to support it I think you'd have to have all PC133 memory and set the proper jumper on the MB to get any benefit.

[couriers]

The motherboard supports both 66 & 100 FSB. The current chip is 66 but the new one going in is 100, not sure if that matters. Also, I was incorrect on the current memory status. There is a single 256 PC100 & a single 256 PC133 module and not 2 PC100. I would assume that the PC133 is utilizing its backwards compatibility to work with the PC100 at the 100 FSB speed. It looks like I'll just save the money and go with only 1 extra PC133 strip to max the board out. Thanks for the help.

[Tarkus]

If your motherboard was built for it PC133 is definitely better than PC100. The higher the number the better. This is just like PC1066 is better than PC800. That's the way it works. :)

Tarkus

P.S. I don't know about using PC133 on a motherboard designed for PC100 though.

[Samdari]

Using PC133 memory on a PC100 motherboard should not be a problem. You are, in essence, underclocking the memory. The memory is cheaper because the market went to DDR while manufacturers were still producing PC133 memory. In about a year (less?) much faster DDR memory will be cheaper than PC133, etc.

As an exercise left to the reader, try to find 32MB 72 pin Simms.

[Tarkus]

Originally posted by Samdari
Using PC133 memory on a PC100 motherboard should not be a problem. You are, in essence, underclocking the memory.
According to Intel this is yes and no. Some boards may work with it and others won't. It depends on the board. Many boards will do exactly what Samdari states, that is, they will underclock the memory. However, other boards may have a problem with this so Intel does not recommend doing this unless the board specifically states it supports PC133. On the other hand, if you are not really concerned about what might happen, go for it. :)

Tarkus

[MizzouRah]

We use PC133 memory in most pc's that only utilize PC100, but like Tarkus said, this may not work on all motherboards. Try it and if it doesn't work, take it back for PC100.


Todd

[Daimyo]

Originally posted by Samdari
As an exercise left to the reader, try to find 32MB 72 pin Simms.

I've got 4 I'm not using... you want some? :)