RE: Compatibility of 2 different sticks of RAM

[Orangeman]

I have a question about RAM. Right now I have a 128mb stick of ram in my computer. Its CAS latency is 3, it is non-parity and it is non-ecc. It is also 10ns. Jumper settings are set for 100 bus speed which is the correct bus speed for this type of RAM.

I have another stick of 256mb but it is 133 ram. It is again, CAS latency of 3, non-parity non-parity, and non-ecc but its ns speed is 8 not 10. If I keep the same jumper settings, currently set on RAM bus speed of 100, can I add the 256mb stick to the 128mb stick for a total of 384mb? Or should I just add the 256 and forget about the 128?

My mobo will take the 256mb. It is a Tekram P5M3-A+ with a VIA Apollo MVP3Chipset.

[NooNoo]

You CAN mix and match 100/133 - however it can be an unstable combination, put the pc100 stick in the first slot, the second 133 stick will then be treated as pc100 as well.

Then see how it flies..

[confus-ed]

More mem = more speed, faster mem = more speed

all = more

So I dunno - try benchmarking it, you've got everything. Nice experiment?

Off the top of my head(isn't everything ?...No that's over it!) then this'll be o/s dependent, the more mem your system wants the less gain from having faster mem, this is a k6 or a Cyrix chip? So 100, unless we want to o/c then 133 and forget the Pc100, but is 128 extra mem more gain in performance ......

Tell us when you figure it out...

Here's the m/b

[Orangeman]

Q)the more mem your system wants the less gain from having faster mem, this is a k6 or a Cyrix chip? So 100, unless we want to o/c then 133 and forget the Pc100, but is 128 extra mem more gain in performance ......

A)I'm not trying to overclock. Its not about extra speed. I'm already maxed-out there. I do alot of work with jpg's and bmp's so I would like a bit more 'gas' when I use my machine.

Also, I am using an AMD K6/2-500 cpu. I'll let you know in a few days how it works out.

Thanks,
Orangeman

[Platypus]

Depending on the design of the board, with 512K of cache, you may run into a cacheable memory limit rather than DIMM compatability. Many Socket7 boards needed 1M or 2M of 2nd level cache to effectively run over 128M of RAM. For example, if you find the system benchmarks well with 256M, but poorly with 384, the limit for caching will be 256M. One of the limitations of the Socket7 architecture.

[Orangeman]

Well, it appears you were right Platypus. I tried my little experiment. The good news is that it worked, the 256mb of 133 RAM did work with the 128mb of 100 RAM. Jumper settings were set for 100 bus speed. The bad news is that Internet Explorer started crashing and the programs actually loaded 10-25% slower with the combination.

When I took out the 128 and just used the 256 my system actually ran faster and no more problems with Explorer.

Thanks People,

Orangeman.

[Orangeman]

Another question if you could Platypus.

I have 512mb of L2 (motherboard) Cache. Does that mean that my maximum limit is going to be 256 or 512 of total RAM?

[MacGyver]

You actually have 512k of cache. The purpose of cache is to help your CPU by buffering data, it has nothing to do with system RAM.

[FatalException0E]

quote:

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Originally posted by Orangeman:
Well, it appears you were right Platypus. I tried my little experiment. The good news is that it worked, the 256mb of 133 RAM did work with the 128mb of 100 RAM. Jumper settings were set for 100 bus speed. The bad news is that Internet Explorer started crashing and the programs actually loaded 10-25% slower with the combination.

When I took out the 128 and just used the 256 my system actually ran faster and no more problems with Explorer.

Thanks People,

Orangeman.

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I think your problem may be the RAM itself, and not compatibility or anything stranger. SD-RAM that's 10ns is usually 66mhz. PC100 and PC133 will generally be 7-8ns

[Platypus]

quote:

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Originally posted by Orangeman:
Does that mean that my maximum limit is going to be 256 or 512 of total RAM?

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To add to MacGyver's accurate reply, your board can recognise a maximum of 768M, the BIOS/memory controller combination can handle up to a 256M DIMM in each slot. Due to the caching strategy of common SuperSocket7 support chipsets, most boards need 2M of cache for the cache memory to be able to "span" the maximum memory the board can utilise.