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Mac Pro RAM problems help needed. I’m flummoxed.

E

Emberfall

macrumors newbie
Original poster
Jan 20, 2010
19
0
I own a Apple Mac Pro 1.1 Xeon Quad Core 3.0 3Ghz and want to upgrade the RAM. It has the original 4x 512MB installed and runs fine, profiler sees all the ram.

I purchased this,

CORSAIR VSA4GBKITFB667D2 4GB (2x2GB) PC2-5300 (DDR2-667) FBDIMM 240-Pin Memory Retail

http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10008402

I bought it locally at Microcenter for $119, though I can’t seem to find it on their website. I installed it and at first all seemed well. Then my fans started going crazy. I did some research and tried some things like resetting the PRAM. When I restarted the profiler could no longer see some of the memory and there was a red light on the riser card. I tried a variety of configurations of the RAM as I was seeing mixed information online. Nothing worked. With just the two new modules installed one in 1A (top riser) and one in 2A (bottom riser) it only saw the top module. So figuring that one was bad I exchanged them yesterday.

Got home and installed just the two new modules. Again, the profiler only see’s one. Tried a variety of configurations. With the new and old memory. The profiler seems to randomly not see memory in different slots. Reinstall original memory and everything is fine. Slots that it previously said were empty are shown as full.

I could really use some help, am feeling quite frustrated and don’t know what direction to go :(
 
I have not yet tried cleaning all the contacts. I will do so later today. The fact that it works with the four original RAM modules has me confused.
 
Emberfall said:
I have not yet tried cleaning all the contacts. I will do so later today. The fact that it works with the four original RAM modules has me confused.
Click to expand...

The problem is you installed them wrong. You have to install them in pairs (so 1A and 1B, not 1A and 2A). See the manual, which explains how to add additional memory to the Mac Pro (FYI, it's one pair in Top at 1A and 1B, second pair in Bottom at 2A and 2B, third pair at Top in 1C and 1D, and last pair in Bottom at 2C and 2D).
 
Aggie, I tried it that way as well. I tried a variety of configurations. The manual is a bit unclear to me, but I did try it with the new memory in 1A and 1B. It only recognized 2g of the 4. I tried it with only the new memory in the top riser and the bottom empty, with only the new memory in the top riser and with two 512s below in riser B, with the new memory in the top and one 512 in slot 3A and the rest in the bottom riser. I got all kinds of strange results in what slots it said were empty. And the highest amount of RAM it recognized was an odd 2.5G
 
Emberfall said:
Aggie, I tried it that way as well. I tried a variety of configurations. The manual is a bit unclear to me, but I did try it with the new memory in 1A and 1B. It only recognized 2g of the 4. I tried it with only the new memory in the top riser and the bottom empty, with only the new memory in the top riser and with two 512s below in riser B, with the new memory in the top and one 512 in slot 3A and the rest in the bottom riser. I got all kinds of strange results in what slots it said were empty. And the highest amount of RAM it recognized was an odd 2.5G
Click to expand...

Well, I was only going by your nomenclature (i.e., 1A, etc.), but the first pair should go in the top closest to the pins for the riser.

BTW, how were the 4 originals placed (1 pair in top and 1 pair in bottom)?
 
Sorry if I was unclear. My original post did not list all the configurations I tried.

Yes the RAM that it has are all the same and there are two in the top riser and two in the bottom. In the first two slots of each riser.
 
Sounds like you've been putting them all over the place. :)

Did you check the Corsair website to see if this memory is compatible? It does look compatible according to the specs.
 
I did and I actually bought it in the Mac section of Microcenter. The package specifically says for Mac Pro. It is the DDR2-667 which is what my profiler says it needs. Unless I'm missing something it is compatible.
 
I came home, cleaned everything and reinstalled the memory as you suggested. The new memory in slots 1 and 2 on the top riser. Two of the old ones in slot 3 and four and two in slots one and two in the lower riser. On reboot there was a red light next to slot 1 and the profiler did not see neither the new memory nor the two below it on the lower riser. Removed and reinstalled the old memory, two up and two down and things are back to normal again. Is it possible that I have to have four of the 2g?

Specs are here

http://support.apple.com/kb/SP30

says it supports up to 16G (8 x 2G)
 
It's dual channel, so what you did looks okay. If you only put 2 in the top that should work. If you put two 2's in the top and two 1's in the bottom, that should work too.

See if two 512's in the top work.
 
See if this helps.
FYI I had the same problem & it was the memory itself. Tried it with a new pair & didn't have any problems.
 

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Gman257 said:
See if this helps.
FYI I had the same problem & it was the memory itself. Tried it with a new pair & didn't have any problems.
Click to expand...

I don't think it's the memory, since he's already switched it out once. I'm just not sure if he can mix memory like he's doing with the 512's and the 2's. If he put the 2 512's in like I said, and they work, then the two 2's have to work in the same slots or there is a memory problem.
 
Ok, I think you have it Aggie (I'm a she by the way) I put two 512's in the top and it was fine. I took them out and put the two 2g in the top and they work. Only by themselves though. I cannot put any of the old memory back in and have it still work.

4G is better than what I had but I still don't get why I cannot run the 6G. I've seen nothing that says that would be the case. It seems like others are having no problem with it and the manual does not address it nor does the packaging or web info on my new memory. Very strange.

I'm happy that it may not be some bigger problem though.
 
I have a Mac Pro 1,1 as well with 4 x 1GB sticks & 4 x 512MB sticks for a total of 6GB
 
Emberfall said:
Ok, I think you have it Aggie (I'm a she by the way) I put two 512's in the top and it was fine. I took them out and put the two 2g in the top and they work. Only by themselves though. I cannot put any of the old memory back in and have it still work.

4G is better than what I had but I still don't get why I cannot run the 6G. I've seen nothing that says that would be the case. It seems like others are having no problem with it and the manual does not address it nor does the packaging or web info on my new memory. Very strange.

I'm happy that it may not be some bigger problem though.
Click to expand...

Gman257 said:
I have a Mac Pro 1,1 as well with 4 x 1GB sticks & 4 x 512MB sticks for a total of 6GB
Click to expand...


From what I know from my experience with
memory, you usually run into problems if you mix different manufacturers memory. So, that's why I think the 2's and 512's don't work on the same riser. I've had to throw away RAM when upgrading. So, you might be able to put all the 512's on one riser and the 2's on another. However, who knows with Apple. They might require the last two slots to be filled with 2's to work ( giving you 10, which wouldn't be too bad, since you'd at least not be throwing away 2 GB of RAM).
 
Here's how mine is:
DIMM Riser A/DIMM 1:

Size: 1 GB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x80AD
Part Number: 0x48594D5035313241373243503844332D5335
Serial Number: 0x08322512

DIMM Riser A/DIMM 2:

Size: 1 GB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x80AD
Part Number: 0x48594D5035313241373243503844332D5335
Serial Number: 0x08322002

DIMM Riser B/DIMM 1:

Size: 1 GB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x80AD
Part Number: 0x48594D5035313241373243503844332D5335
Serial Number: 0x72951005

DIMM Riser B/DIMM 2:

Size: 1 GB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x80AD
Part Number: 0x48594D5035313241373243503844332D5335
Serial Number: 0x72951105

DIMM Riser A/DIMM 3:

Size: 512 MB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x802C
Part Number: 0x39485446363437324A592D36363742344433
Serial Number: 0xD50BA6F6

DIMM Riser A/DIMM 4:

Size: 512 MB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x802C
Part Number: 0x39485446363437324A592D36363742344433
Serial Number: 0xD50BA6F7

DIMM Riser B/DIMM 3:

Size: 512 MB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x830B
Part Number: 0x4E54353132543732553839413842442D3343
Serial Number: 0x2D5A0A51

DIMM Riser B/DIMM 4:

Size: 512 MB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x830B
Part Number: 0x4E54353132543732553839413842442D3343
Serial Number: 0x72580A54
 
Gman is your RAM all the same manufacturer? It bothers me that if I keep this it seems like I'm married to the corsair memory. What if it is unavailable when I want to add more. I think I will call their customer support when I get a chance.
 
So I put 2 of the old 512's in the lower riser under the new modules and it is working. I know I tried it before and it did not work. Now I have 5G of RAM I'm scared to put in the last two but 5G seems like an odd number to have.
 
You need to buy RAM that has a certified Apple thermal module; a good reputable reseller for that would be Macsales.com (OWC). If you don't buy compatible RAM, the computer will think the computer is overheating and run the fans at maximum.
 
It is certified, bought at the Apple store in Microcenter. Says "for MacPro" right on the package :D
 
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