[Drash]

Just browsing Crucial's site and they recommend a PC100 256MB SODIMM for my Strawberry iMac, using their memory selector. However if I search just for chips they do a PC133 256MB SODIMM for half the price - everything else seems to be the same apart from the speed. Their blurb says that they can only guarantee compatability if you use their choice from their memory selector....

Is the faster, cheaper DIMM ok? If so I can max out the iMac for the price of their recommended 256 MB DIMM. It seems all Crucial SODIMMs are short enough to fit in the bottom slot from their info, but I have emailed them to get dimensions for the DIMMs in question, just to be sure.

thanks

[OldManMac]

Actually, that's PC66Mhz memory machine, but the others will work; they'll just slow down to the bus speed.

[Drash]

Are you sure about slowing the bus? I thought that the PC133 relates to the max speed of the DIMM - 133 MHz, so putting it in a slower bus wouldn't be a problem. However, were I to put a 66MHz DIMM in a 100 MHz or more machine then that would slow things down, if it worked at all.

I did a search on DIMM on this forum before I posted, but most posts were from a while ago when PC133 was more expensive than PC100, so no-one had tried the PC133. Apple's help does say a DIMM has to be 10nS or faster and Crucial say the PC100 is 8nS and the PC133 is 7.5nS. I also read a TIL that said to fit PC100, but that was written before PC133 was really available. I was just worried that there might be a hidden difference not in the simple specs Apple and Crucial give out - I've been caught out before like that, so I wanted to check.

Regards

[Jens Peter]

Originally posted by Drash
Are you sure about slowing the bus? ...

I think that what KarlG meant was, that the bus on your iMac is at 66 MHz, and if you buy 133 Mhz ram, it will slow down to 66 Mhz.

I have a iMac with a 100 Mhz bus, and just last week, I got 2 * 133MHz modules for it. It runs great, no problems at all.

Jens Peter.

[OldManMac]

Originally posted by Jens Peter:
I think that what KarlG meant was, that the bus on your iMac is at 66 MHz, and if you buy 133 Mhz ram, it will slow down to 66 Mhz.

I have a iMac with a 100 Mhz bus, and just last week, I got 2 * 133MHz modules for it. It runs great, no problems at all.

Jens Peter.

That's exactly what I meant. I've put PC133 RAM in a PC100 G4, and I've also sold lots of faster memory to put in older machines.

[Drash]

I just re-read your your post. Doh!!! You're right, I totally mis-read what you were saying.

Looks like I'll be buying the PC133 DIMMs -- Crucial have just confirmed that the part I'm interested in (CT32M64S4W7E) is just 1 inch high, so they'll fit in both slots.

[Kenneth]

I bought a 256MB PC-100 SO-DIMM RAM for my iBook 300 back in the old days. Then I removed it and put a 512MB on the iBook, it works fine. I took that 256MB RAM and put it into my iMac 333. It only recognized as 128MB. I'm running 10.2.4 now which means I have done all the firmware patch.

I don't remember that 256MB RAM chip in specific.. but I somehow remembered it was a "32 x 8" printed on the module. Will it be the casue?

Over at Crucial.com, the RAM sold for iBook 300 and iMac (233-333) are in different part number. Since I also want to replace my current freaky 256MB module to a "real" 256MB module. I need to figure out will those PC-133 "32 x 64" really work on the 1st. gen iMac?

[Drash]

The SO DIMM finally arrived, and I fitted it in the bottom slot and it works ok. It is so small compared with the 128MB I bought a couple of years ago!

To Kenneth re. Crucial's ref. nos. It seems that they use different ref. nos. for chips that should be the same so that they can track what machine you bought it for - they have a 100% compatability guaratee if you use their chip chooser based on your hardware. But they state that this guarantee doesn't apply if you use the advanced chooser which doesn't make recommendations using your hardware, also if you do choose wrong they reserve the right to charge a re-stocking fee.

I'm no expert on X (I'm still using 8.6, but was thinking of getting X to have a bit of a dabble), but having 10.2.4 in itself doesn't imply you have the right firmware. Unless of course 10.2.4 wont run unless... , you dont state this to be the case and I dont know otherwise, but I thought firmware was an issue for original iBooks to be able to recognise 256MB DIMMs. Have you tried downoading the update and reinstalling? If its already there it should say so.

Regards

[Kenneth]

Thanks for the feedback. I'll go check out their RAM again. I'm sure your iMac is snappy? now.