Weird RAM lose

[Solidww]

tcsearth - Very good points. I think this could be one of the missing points in the equation. When, I have slots 1 or 2 filled no worry. When I fill up 3 or 4, HAVOK!!!! When I swap the RAM from slots 1 or 2 to 3 or 4 they are no longer read. This drove me up the wall for a while. I was thinking it was the power supply but it kept doing the same thing when all I had was the boot drive, and DVD attached.



Ok, this is what I meant by slot 1,2,3,etc....

Imagine the rear panel toward the back of the tower. Then imagine the processor close to the center of the board. Now the RAM slots would be as follows.
Processor - 2(BLUE)-1(WHITE)-4(BLUE)-3(WHITE)

I am awaiting to get to the bottom of this soon.

 

[tcsearth]

Okay, according to your description, your ram placement is different than mine. Under conventional knowledge, your ram should be put in pairs on the same channel.

which means, the same color of slots are one channel. and this is a dual channel board. ( one pair of white, one pair of blue). you were "suppose" to fill one channel up before you place another one on the other channel.

based on you said 1> the bios sees all four, yet lead to panic; and 2>all four rams work on 1+2 , but don't work with all four:

try placing 1/3 or 2/4 (same color slot with 2 rams). see if it will boot correctly.

If it boots correctly - you problem is most likely the firmware-bios OR the OSX.

If it does not boot correctly - or if it only reads one ram instead of two - well that opens up a list of possibilities. we need to look into the details of your ram to narrow it down. (what speed? what rank? ....and how much you paid for them )

---I am a newbie on OSX86; however I have pretty decent knowledge of memories...

 

[Solidww]

Ok, that does make perfect sense.
I will try this again when I get a chance on the machine. If my memory serves me well, when I did 1 and 3 or 2 and 4 RAM slots then it would boot and run fine. But, OSX couldn't actively use both RAM chips. The really weird thing about the situation is that it will see that the RAM slots are occupied it just won't actively use them.

In effect the problem just got weirder and weirder.

 

[tcsearth]

Well, it is actually not that weird (maybe just a little)...

The OS/and or BIOs can only read so many channels and ranks on a board. Over the limit, it will just ignore it, therefore when you see the slots being "occupied and recognized" doesn't mean it is "usable" by the system. So if you wanna get to the root of the problem, you need to know what ram you are using...

post your results! good luck.

 

[Solidww]

Ok, after a while of trying I have come to the bottom of this dilemma.

tcsearth - Thanks for your continued interaction on this matter. Your info was backed by several people. Two of which have been building computers for over 25 years.

I looked at the RAM sticks and saw that even though they are the same Corsair XMS3 4GB sticks. They were not all made at the same time nor from the same batch. Then, I looked at the chips on the RAM sticks and they didn't all match. So, to make a long story short I had mismatched chips which were deactivating Dual Channel mode. I also had bad RAM sticks. This was causing the kernel panics. Now, I have two sticks in the machine running in Dual channel mode and no kernel panics.
So, now to get a refund or exchange on the two RAM sticks that were bad.

 

[tcsearth]

Glad you got it figured out! Happy mac=happy user.

Before I got involved in the memory business I just grab which ever was onsale on amazon...later on I learned that there are many differences - and those on sale items are normally made by module houses where they need to push out a bunch of older dies, mixed returns, or what ever they need to get rid of. Therefore the quality is anyone's guess.

Personally I use the original Samsung module with specs equal or better than Apple original parts.

Good luck!

 

[Solidww]

I will agree with you on that one. The RAM, I bought for two MacBooks has been wonderful. Never an issue on both purchases. They weren't Samsung but from an authorized dealer with a proven track record. Now, to get these modules returned and see what happens.
I am thinking that 16 Gigs is really over kill for me. Not, that I won't use it. Its, just that I have been fine with 4-6 for almost a year now. I was really wanting to get into video editing but I haven't really been enjoying it much. Maybe, I just need to give it more time.

 

[tcsearth]

16GB is overkill....LOL, I did that just to see if it really runs....I don't think you need that unless you are running on a server board with Xeon cpu...

I do plenty of video edit on iMovie (rarely gotta bring out the big guns of FCP) and photoshop editing. I currently run on 8GB of 1333, with i5-760. it has been smooth sailing so far...

(if you have trouble obtaining high quality rams just PM me. I might be able to help.)

cheers!

 

[Solidww]

Well, I went with the Xeon processor because of its ability to do work. Its a great processor for what I do. I also understand that its a little overkill. Off course I found that out too late. I am now at a cross roads. I can keep the machine and just work with it as is. I can change somethings up and get a smaller machine that doesn't need as much juice. Lastly, I can sell it and just stick to the MacBook. I am finding out that its really all I am needing. Weird how things work.
As for the RAM, I am going to make contact today to get them replaced.

Thanks again for your help.