I have an older (vintage Early 2001) iMac (500 MHz iMac Indigo)
that runs slowly. I have 256 MB memory loaded, but the board will
support up to 1 GB. I want to max out the memory and make this
computer more useful.

According to the Apple on-line specs, it can used either PC100
or PC133 SDRAM DIMMs. (It currently has 1 of each.)

Here's where it gets confusing:

I have seen ads for PC133 SDRAM DIMMs that say
they aren't compatible with Apple computers, and
they direct me to higher priced DIMMs that they
say are compatible. There are numerous other ads that
don't say one way or the other.

Without buying all these different DIMMs and plugging
them into my computer, how can I tell from the DIMMs'
technical specs whether they will work in my computer?

Or will any PC100 or PC133/non-ECC SDRAM DIMMs work in
this computer?

In article <party-85D1FE.18093623102005@news-fe-03.texas.rr.com>,
Hugh Gibbons <party@my.house.com> wrote:

> Or will any PC100 or PC133/non-ECC SDRAM DIMMs work in
> this computer?

IIRC the memory is not a normal stick. I would not use multiple speeds
of memory, as the machines tend to choke on them. I just go to
http://www.crucial.com and get what I need.


--
Ross Winn
Freelance Geek & RPG.net Columnist

In article <party-85D1FE.18093623102005@news-fe-03.texas.rr.com>,
Hugh Gibbons <party@my.house.com> wrote:

> Or will any PC100 or PC133/non-ECC SDRAM DIMMs work in
> this computer?

IIRC the memory is not a normal stick. I would not use multiple speeds
of memory, as the machines tend to choke on them. I just go to
http://www.crucial.com and get what I need.


--
Ross Winn
Freelance Geek & RPG.net Columnist

In article
<ross_winn-AB2AF1.11480724102005@news-server1.tampabay.rr.com>,
Ross Winn <ross_winn@mac.com> wrote:

> In article <party-85D1FE.18093623102005@news-fe-03.texas.rr.com>,
> Hugh Gibbons <party@my.house.com> wrote:
>
> > Or will any PC100 or PC133/non-ECC SDRAM DIMMs work in
> > this computer?
>
> IIRC the memory is not a normal stick. I would not use multiple speeds
> of memory, as the machines tend to choke on them. I just go to
> http://www.crucial.com and get what I need.

Crucial says, as I thought, it needs unbuffered, non-parity
SDRAM. Is there something else?

Apple specs say PC100 or PC133 will work. My present configuration
(since I bought it four years ago) has one PC100-128MB DIMM and one
PC133-128 MB DIMM.

In article
<ross_winn-AB2AF1.11480724102005@news-server1.tampabay.rr.com>,
Ross Winn <ross_winn@mac.com> wrote:

> In article <party-85D1FE.18093623102005@news-fe-03.texas.rr.com>,
> Hugh Gibbons <party@my.house.com> wrote:
>
> > Or will any PC100 or PC133/non-ECC SDRAM DIMMs work in
> > this computer?
>
> IIRC the memory is not a normal stick. I would not use multiple speeds
> of memory, as the machines tend to choke on them. I just go to
> http://www.crucial.com and get what I need.

Crucial says, as I thought, it needs unbuffered, non-parity
SDRAM. Is there something else?

Apple specs say PC100 or PC133 will work. My present configuration
(since I bought it four years ago) has one PC100-128MB DIMM and one
PC133-128 MB DIMM.

In article <party-386021.19370124102005@news-fe-03.texas.rr.com>,
Hugh Gibbons <party@my.house.com> wrote:

> Apple specs say PC100 or PC133 will work. My present configuration
> (since I bought it four years ago) has one PC100-128MB DIMM and one
> PC133-128 MB DIMM.

I have always been advised against mixing memory speeds. That is all I
know.


--
Ross Winn
Freelance Geek & RPG.net Columnist

In article <party-386021.19370124102005@news-fe-03.texas.rr.com>,
Hugh Gibbons <party@my.house.com> wrote:

> Apple specs say PC100 or PC133 will work. My present configuration
> (since I bought it four years ago) has one PC100-128MB DIMM and one
> PC133-128 MB DIMM.

I have always been advised against mixing memory speeds. That is all I
know.


--
Ross Winn
Freelance Geek & RPG.net Columnist

In article
<ross_winn-55C8F4.01230025102005@news-server1.tampabay.rr.com>,
Ross Winn <ross_winn@mac.com> wrote:

> In article <party-386021.19370124102005@news-fe-03.texas.rr.com>,
> Hugh Gibbons <party@my.house.com> wrote:
>
> > Apple specs say PC100 or PC133 will work. My present configuration
> > (since I bought it four years ago) has one PC100-128MB DIMM and one
> > PC133-128 MB DIMM.
>
> I have always been advised against mixing memory speeds. That is all I
> know.

I have seen/ran several machines with mixed memory speeds. Most of the
time they work ok. You do get a performance hit sometimes (PC133 is
forced to run at 100 when paired with a PC100 stick) but most systems
chug along ok. Only a few times it has been a problem.

With that said, avoid mixing if you can.

--
Ed Heagle

In article
<ross_winn-55C8F4.01230025102005@news-server1.tampabay.rr.com>,
Ross Winn <ross_winn@mac.com> wrote:

> In article <party-386021.19370124102005@news-fe-03.texas.rr.com>,
> Hugh Gibbons <party@my.house.com> wrote:
>
> > Apple specs say PC100 or PC133 will work. My present configuration
> > (since I bought it four years ago) has one PC100-128MB DIMM and one
> > PC133-128 MB DIMM.
>
> I have always been advised against mixing memory speeds. That is all I
> know.

I have seen/ran several machines with mixed memory speeds. Most of the
time they work ok. You do get a performance hit sometimes (PC133 is
forced to run at 100 when paired with a PC100 stick) but most systems
chug along ok. Only a few times it has been a problem.

With that said, avoid mixing if you can.

--
Ed Heagle

Hi!

I see no reason why regular PC133 wouldn't work perfectly. In fact, I have
several iMacs and PCs that I have moved memory between without issue.

The biggest thing is to have *quality* memory, especially if you use Mac OS
X...other than that, it doesn't matter where you get your memory. If it fits
the spec, it will work.

William

Hi!

I see no reason why regular PC133 wouldn't work perfectly. In fact, I have
several iMacs and PCs that I have moved memory between without issue.

The biggest thing is to have *quality* memory, especially if you use Mac OS
X...other than that, it doesn't matter where you get your memory. If it fits
the spec, it will work.

William

> I see no reason why regular PC133 wouldn't work perfectly. In fact, I have
> several iMacs and PCs that I have moved memory between without issue.

primarily because "regular" sticks in the PC world are about twice as
long. iMacs do use a different size module than "regular" PCs.

--
Ross Winn
Freelance Geek & RPG.net Columnist

> I see no reason why regular PC133 wouldn't work perfectly. In fact, I have
> several iMacs and PCs that I have moved memory between without issue.

primarily because "regular" sticks in the PC world are about twice as
long. iMacs do use a different size module than "regular" PCs.

--
Ross Winn
Freelance Geek & RPG.net Columnist

Hi!

> primarily because "regular" sticks in the PC world are about twice as
> long. iMacs do use a different size module than "regular" PCs.

I don't think we're talking about the same thing. The iMacs of which I speak
are the G3 models from 350-500MHz, some of which have Firewire onboard. I
believe these are the majority of the "Summer 2001" lineup. I am not talking
of the later G4-based machines, or any of the early units that have tray
load CD-ROM drives or an internal fan.

For *this specific type of iMac*, they do take standard PC133 DIMMs, same as
PCs. I've seen modules with varying height, but it doesn't seem to matter. I
have machines with both tall and short modules in place.

It is my understanding that the OP has a Summer 2001 series machine to which
my original advice will apply.

For the record, though, the G4 iMac (with flat panel display) does not use a
DIMM in the "user accessible memory expansion". It uses a laptop-style
SODIMM, which can also be found in the laptop PC world. However, if you take
a G4 iMac apart, you will find a DIMM in place on the other side of the
logic board.

William

Hi!

> primarily because "regular" sticks in the PC world are about twice as
> long. iMacs do use a different size module than "regular" PCs.

I don't think we're talking about the same thing. The iMacs of which I speak
are the G3 models from 350-500MHz, some of which have Firewire onboard. I
believe these are the majority of the "Summer 2001" lineup. I am not talking
of the later G4-based machines, or any of the early units that have tray
load CD-ROM drives or an internal fan.

For *this specific type of iMac*, they do take standard PC133 DIMMs, same as
PCs. I've seen modules with varying height, but it doesn't seem to matter. I
have machines with both tall and short modules in place.

It is my understanding that the OP has a Summer 2001 series machine to which
my original advice will apply.

For the record, though, the G4 iMac (with flat panel display) does not use a
DIMM in the "user accessible memory expansion". It uses a laptop-style
SODIMM, which can also be found in the laptop PC world. However, if you take
a G4 iMac apart, you will find a DIMM in place on the other side of the
logic board.

William