Prev: /private/var/folders/? Also, The Wrestler
Next: Office 2008 and Snow Leopard Services
From: Dave Baxter on 9 Mar 2010 18:34
Woody wrote:

>> So for my HP laptop, I can just buy PC2-6400 and it will clock down to
>> 5300 (it was cheaper than 6400 at the time), and I can do the same for
>> my desktop PC, but I can't with my Mac?

> Don't know, but why would you want to clock your computer down with
> slower memory? It would be better to stick with 2G of faster memory.

I think you mis-read me... I was complaining that I could put 6400 into
a laptop that used 5300 and it would clock down to work at 6400. That's
not slowing the computer down as the laptop in question only works at 5300.

Likewise for the Mac, the RAM that came with it and that Crucial
recommends is 5300. I have 6400 here which, when fitted to my Mac, I
expected would clock down to the 5300 that the Mac wants. Apparently my
Mac isn't capable of doing that, which I find quite disappointing!

Dave
--
(remove spamblock or reply to group)
From: David Empson on 9 Mar 2010 18:40
Dave Baxter <dave(a)nospamhereplease.fire_stryke.com> wrote:

> As subject, really.
>
> Crucial says 4Gb, Google seems to either say 3 or 4Gb.

Assuming your model is the MacBook Pro (15-inch Early 2008), it will be
identified in System Profiler as "MacBookPro4,1".

That model officially supports 4 GB as per Apple's specifications, and
unofficially it has been demonstrated to work with 6 GB (4+2), but not 8
GB (4+4).

> I've got a pair of 2Gb PC2-6400 SODIMMs. Crucial branded. Put both of
> them in, no boot. Put one in, no problem. Put one in with a 1Gb SODIMM,
> no problem. Put two 1Gb SODIMMs in, no problem.

As per the rest of the thread, you need PC2-5300, not PC2-6400.

Assuming the same general mechanisms are still in use as they were back
in the PC-133 era, the issue is likely to be the timing information
programmed into the Serial Presence Detect EEPROM on the DIMMs.

In order for the memory to work in a Mac, the SPD EEPROM must be
programmed correctly, AND it must include parameters that specify the
timing information for the memory bus speed used by your particular Mac
(667 MHz).

If the Crucial PC2-6400 DIMMs only include timing information for an 800
MHz bus, your MacBook Pro won't recognise them.

In principle, the SPD EEPROM could be reprogrammed to provide the
necessary timing information, but it is easier to just return them and
buy the correct speed.

--
David Empson
dempson(a)actrix.gen.nz
First  |  Prev  | 
Pages: 1 2
Prev: /private/var/folders/? Also, The Wrestler
Next: Office 2008 and Snow Leopard Services