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parabology · Dec 11, 2007, 03:56 AM

Hi guys,

I got a new MacBook a couple of weeks back with the default 1GB of RAM. The 4GB ram option was a whopping $800+ so I obviously passed on that, since I can buy 2x2GB sticks for a little over $100. They came in and I went in to upgrade them, but when I put them both in, the computer wouldn't start. Or more specifically, the white light came on and the CD drive started up but the screen wouldn't start and the chime didn't go. Naturally, that wasn't a good sign so I tried each of the sticks separately, same thing.

I thought maybe I had screwed up buying the right type of RAM but everything seemed to check out - and I didn't break the computer or anything because putting the original sticks back in still worked. Finally, I tried one last thing randomly -- I put in one of the original 512 MB sticks and one of the new 2GB sticks and magically, it worked. This worked no matter which of the 2GB sticks I put in.

So now I'm running with 2.5GB of RAM even though I have another 2GB stick sitting here. I'm wondering what exactly is going on here -- has anyone seen this before? If I can't figure this out, 2.5GB is alright for now (I do mathematical/scientific work so the more ram the merrier) but I really would like to figure out how to max the RAM on this thing.

Thanks!

Pierre B. · Dec 11, 2007, 06:39 AM

Originally Posted by parabology

So now I'm running with 2.5GB of RAM even though I have another 2GB stick sitting here. I'm wondering what exactly is going on here -- has anyone seen this before? If I can't figure this out, 2.5GB is alright for now (I do mathematical/scientific work so the more ram the merrier) but I really would like to figure out how to max the RAM on this thing.

Thanks!

This is strange. Have you checked if the system reports correctly 2.5 GB?

ibook_steve · Dec 11, 2007, 02:25 PM

Originally Posted by Pierre B.

This is strange. Have you checked if the system reports correctly 2.5 GB?

Exactly. It may have booted because you have the original 512 stick in, but the machine may not be seeing the other 2 GB.

Steve

parabology · Dec 11, 2007, 03:51 PM

Yes, it does seem to be running 2.5GB. System Monitor and System Profiler both say 2.5GB and System Profiler lists the DIMMs correctly as well. I'm using over 512 MB of memory and things are still zippy and I can't hear the hard drive churning so I don't think the memory just isn't working.

Weird situation...

ibook_steve · Dec 11, 2007, 04:05 PM

Does it boot with only 2GB (either stick in either slot)?

Steve

analogika · Dec 11, 2007, 06:44 PM

What does the Apple HArdware Test say?

chabig · Dec 11, 2007, 07:44 PM

Chances are that you simply didn't seat the memory well enough. I'm not saying that nothing is broken, I'l must pointing out the most probably cause. I'd try reseating the 2GB DIMMs again.

Chris

parabology · Dec 11, 2007, 08:47 PM

It didn't work when I put either 2gb stick in by itself. I've tried it multiple times and I'm pretty sure I'm putting them in all the way (every time I try with the 512/2gb combo, it works). I'll try again though to be sure. I'll try the hardware test though since the computer works fine with the 2.5gb in and doesn't boot at all with just 2gb or 4gb I don't know how much help it will be.

Either way, strange problem. If I can't figure it out, I'll take it to the apple store and see whats going on.

Oh, the one thing that might be a little strange is that the RAM sticks are clocked at 800MHz rather than 667 MHz but both the manufacturer and retailer of the sticks as well as other sources online have said that they will clock down if the motherboard doesn't support them. Otherwise they meet all the requirements -- non-ECC, non-parity, etc.

ibook_steve · Dec 11, 2007, 10:37 PM

If it doesn't work with either of the 2GB sticks in by themselves, then something is obviously wrong with those sticks. Link to where you got them?

Steve

parabology · Dec 12, 2007, 01:32 AM

Yeah I just checked again about the reseating by first putting in the 512 and 2GB sticks, making sure everything worked, then just taking out the 512 one and leaving the other one alone. Didn't work.

I too would suspect something to be wrong with the DIMMs but either one in conjunction with a 512MB one works perfectly fine, giving me the expected performance of 2.5GB of memory, showing up in the OS and everything. Very strange indeed.

The link to where I got it: 4GB DDR2 SODIMM PC2 4200 5300 6400 2 X 2GB 4 GB 667 800 - (eBay item 280178825858 end time Dec-04-07 03:27:31 PST)

Bought memory from him before and it had no problems.

Do you think its worth taking to the Apple store (will they charge me to look at it?)

Pierre B. · Dec 12, 2007, 05:32 AM

Originally Posted by parabology

Do you think its worth taking to the Apple store (will they charge me to look at it?)

I don't know. What is sure though is that they don't like non-Apple stuff, so if you go there be prepared to hear strange things.

Also, the fact that you did not have problems with memory before from the same seller, does not necessarily means that the modules you have now are trouble-free. In your place I would try to get a replacement.

kerosen · Dec 12, 2007, 08:10 AM

Or try to check them in a non-Apple laptop. If they don't work then they are obviously faulty and try to replace them. If they work ok then the conclusion is that they are not compatible with Macbook for some reasons (latency, speed etc).

Cadaver · Dec 15, 2007, 10:30 AM

Some high-clock speed RAM don't work correctly in Macs. The reason is the Mac will always look to the encoding on the RAM module to set the speed. If its missing the codes for the lower speeds (667MHz in your case), it simply wont work.

These same modules work fine on a PC, since the BIOS can set the speed without looking at the codes on the RAM module (or can be set to ignore the codes).

I have a pair of 1GB high-end overclocked gamer-type DDR RAM modules for my AMD-based PC. They work perfectly in the PC but are not recognized at all by my G5 (which takes the same type of RAM).

The reason one of your modules will work when used with the stock smaller module is because the stock module as proper speed encoding, and the Mac will then clock all RAM to that speed. Without that module, your Mac doesn't know what to do.

I'd say return them if you can. I don't think you'll ever get them to work in the MacBook. Find some 667MHz spec'd RAM instead of 800MHz.

dowNNshift · Dec 15, 2007, 05:23 PM

Echoing what was said above by Cadaver, you must use DDR2 667 non-buffered SO-DIMM modules. Going with no-name generic RAM has its risks, which unfortunately you've encountered.

I recommend returning the RAM if you can and instead purchasing Crucial or Mushkin RAM that is spec'd to your particular MacBook. The best thing to do is use Crucial's memory adviser tool on their website. DDR2 800 RAM is not supported on any generation of the MacBook. Remember, Intel Macs use Boot EFI not BIOS like PCs.

mduell · Dec 15, 2007, 06:19 PM

One or even two speed grades higher is usually fine (IIRC the speed tables are usually 3 entries), but I guess it's not this time. Newegg has 2x2GB Transcend for $83 shipped, and lots of happy reports from Mac owners for the module.

dflek · Dec 18, 2007, 10:30 PM

I have had a similar problem, details below:
- Was running my first-gen blackbook with 2 x third party 1GB 667MHz sticks, no problems
- Recently purchased 2 x 2GB GeiL 667MHz
- System runs fine with 2 x 1GB or 1 x 2GB, but won't run with any combination of 2 x 2GB, 1GB and 2GB. WEIRD!

This probably doesn't help you much! Just wanted to let you know that Macs in general are very touchy with RAM.

mduell · Dec 19, 2007, 06:49 PM

Originally Posted by dflek

I have had a similar problem, details below:
- Was running my first-gen blackbook with 2 x third party 1GB 667MHz sticks, no problems
- Recently purchased 2 x 2GB GeiL 667MHz
- System runs fine with 2 x 1GB or 1 x 2GB, but won't run with any combination of 2 x 2GB, 1GB and 2GB. WEIRD!

This probably doesn't help you much! Just wanted to let you know that Macs in general are very touchy with RAM.

Different problem: the Core Duo Macs are all firmware crippled to 2GB max.

msuper69 · Dec 28, 2007, 02:58 PM

Originally Posted by parabology

...

Do you think its worth taking to the Apple store (will they charge me to look at it?)

You'll have to remove all traces of non-Apple hardware first. Apple won't troubleshoot a system with any non-Apple hardware.

Thus eliminating the reason for taking it in in the first place.

danbrew · 01:10 AM

Are you sure it is a 4g capable Macbook? Wasn't the version that was for sale just before the mid-November release only capable of using 3 gigs (and advertised as 2 gig)?

My first thought is that you have a pre-Santa Rosa Macbook.

Primate Labs Blog : MacBook Performance (November 2007)
In black and white: a review of the Santa Rosa MacBook: Page 1

legacyb4 · Dec 29, 2007, 11:43 AM

I had a nice Christmas surprise for myself; I have a January 2007 black Macbook (2Ghz) so definitely not a Santa Rosa chipset and had purchased 2 x 2GB from Newegg knowing that I would only have access to 3GB per other threads in the forum. I figured I'd just save myself the headache of the paired/unpaired DIMM issue and just get two sticks for that price.

Installed, rebooted, and much to my delight, my Macbook is seeing 4GB!

Originally Posted by danbrew

Are you sure it is a 4g capable Macbook? Wasn't the version that was for sale just before the mid-November release only capable of using 3 gigs (and advertised as 2 gig)?

My first thought is that you have a pre-Santa Rosa Macbook.

Primate Labs Blog : MacBook Performance (November 2007)
In black and white: a review of the Santa Rosa MacBook: Page 1

Simon · Dec 29, 2007, 01:49 PM

Originally Posted by legacyb4

Installed, rebooted, and much to my delight, my Macbook is seeing 4GB!

Yes, a C2D Calistoga MB will accept 2x2GB and also show a total of 4GB in System Profiler. The point is that the chipset can't address the last GB of that memory, so you'll never be able to actually use it. In short: it will show a total of 4 GB, but you can only use 3 GB.

You see this by the way in your image: free + used (used = wired + active + inactive) = 3 GB and not 4 GB. Sorry to rain on your parade, but there's no use kidding yourself. Only a Crestline MB will let you use 4 GB RAM.

legacyb4 · Dec 29, 2007, 02:33 PM

Oops, it looks like I jumped the gun.

Originally Posted by Simon

Yes, a C2D Calistoga MB will accept 2x2GB and also show a total of 4GB in System Profiler. The point is that the chipset can't address the last GB of that memory, so you'll never be able to actually use it. In short: it will show a total of 4 GB, but you can only use 3 GB.

You see this by the way in your image: free + used (used = wired + active + inactive) = 3 GB and not 4 GB. Sorry to rain on your parade, but there's no use kidding yourself. Only a Crestline MB will let you use 4 GB RAM.