Memory advice please

[george]

My Beige G3 has three memory slots,
I have three sticks of memory each of them is pc133x128mb two are of the same make and when slotted in either idividually or together they register half their value whilst the other one registers it's true value.
Am I missing (apart from brain cells) something?.
George.

[george]

Sorry, I missed out that all three are SDRAM.
G

[Bill]

george,what bus speed is your G3?

[Gary S]

The Beige G3 has a 66MHz bus.

What does your System Profiler say George? Does it say you have all the slots filled?

What does it say when you go to the Apple Menu and get the "About this computer"? Does it say 384MB  under Built-in Memory?

Those PC133 sticks should work. They will only run at 66MHz but they should work.

[george]

Bill/Gary S,
The Bus speed is 66mhz.
On OS X (about this Mac)it only gives the total memory 256mb it does not give (as in a G4) a memory overview breakdown.
In the OS 9 the overview is
J3    128mb    DIMM
J4     64mb    DIMM
J5     64mb    DIMM

even although each of the 64mb sticks are in fact 128mb
George

[snuffysbluff]

quote:Originally posted by george:
even although each of the 64mb sticks are in fact 128mb

Could be that the two sticks are in fact 64MB.

[george]

Hi, I have been back to my supplier and he has replaced the two 64mb sticks but the replacements behave in exactly the same way!
George.
 even more

[george]

Gollygosh, I'm beginning to lose my marbles, the replacements were of course 128mb that still behave like 64mb.
George

[kelly]

George. I think you should return it and get different RAM.  

"When ordering SDRAM always verify that it is certified for use with the Apple G3 systems. The G3 requires SDRAM with a serial presence detect chip that tells the system the size and type of the module. It's often a tiny 8 pin chip in the upper corner of the dimm. Some PC SDRAM will work, but it's safer to buy only dimms that are certified for use in the Beige G3 systems...."

http://www.xlr8yourmac.com/G3-ZONE/trouble.html#ram

http://www.xlr8yourmac.com/G3-ZONE/

[Bill]

George, Do have TattleTach Or Dimm first Aid?

Both can give you insight on what is going on this your memory.
TattleTech can tell you a lot more than just memory issues.
You can download the version TT you need here and Dimm First aid here.

You'll have to use them in OS 8 or 9 though. I don't think they have any version for X.?.

-I could be wrong on this- but backwards compatible ram can only go down one stage. Meaning PC-133s will work on 100 bus/100 will work on 66 bus.
Your taking two steps down from 133 down to 66.

Like Kelly stated ... certified ram makes a big difference.

[george]

Hi Bill/Kelly, I see what you are saying and have printed out this page and downloaded the suggested links and now it's back to the drawing or rather the motherboard.
I'll get there.
Many thanks
George

[Bill]

My fingers sore,so not very talkative. <gr>

[Bill]

George.

I was on the phone talking to a ram tech (who makes his bread and butter selling ram) yesterday. I brought up the subject of PC-133s in 66 buses.

His quote:
That is asking to much for a ram stick! Whether it will work for awhile,it's taxing the ram to much and it won't last as long (if it does at all) as it was designed for.
A PC-100 would be much more backwards compatible for a 66 bus.

[george]

Bill, Thanks for the info, I'll take the two 133's back to my supplier this weekend in the hope that he will exchange them.
Will keep you posted.
Ta much.
George.
Off to bed It's 11-30 pm GMT

[george]

Bill, exchanged my two sticks of 128mb x 133 for another two sticks with exactly the same spec, the difference being that the first two (that showed half their true value) had only four chips on the stick whereas the new ones have eight chips on them and they, visually are the same as the one on the board. Hope you can make sense of this as when I look at it, it don't.
Anyway the new ones  now work beautifully which what matters.
George.