MP 1,1-5,1 MBP 3,1 trouble upgrading memory. 8gb show up as 4gb

[Tharayman]

GOt my hands on some apparently 100% similar sticks. One pair shows up as empty, one pair shows up as 4gb and the last pair shows up as 8gb all around. I find this a bit confusing. Is there something funky about the sticks, or is it something about the mac I am not familiar with?

 

[Macschrauber]

You could try to clean the contacts of the sticks and the risers.

Also reseat then a few times. Those sockets had oxidation for way over 10 years.

 

[DeltaMac]

Maybe you can return that RAM, and get the correct spec RAM for your MacPro3,1
Should be PC2-6400 FB-DIMMs
the 8GB can also be a little flaky, even if the chip speed is correct (which yours is not)
And, 4GB is usual max in a slot in a MP3,1 (but someone with more experience will likely correct me on that)

 

[Macschrauber]

8GB could work, but they get damn hot and draw a lot of current rising the energy bill.
Also the memory fan (don't remember the correct name atm) should be ramped up with MacsFanControl or alike.
800 Mhz are tough to get in that size and heat and wattage is even more.


Back in the days I transfered the heat sinks of 512MB sticks to the Samsung sticks.

also with full loaded 64GB the machine gets slow, there is a nvram boot-args setting (maxmem=) to reduce the recognised Ram. If set to 61440 it's ok.

 

[Tharayman]

8GB could work, but they get damn hot and draw a lot of current rising the energy bill.
Also the memory fan (don't remember the correct name atm) should be ramped up with MacsFanControl or alike.
800 Mhz are tough to get in that size and heat and wattage is even more.


Back in the days I transfered the heat sinks of 512MB sticks to the Samsung sticks.

also with full loaded 64GB the machine gets slow, there is a nvram boot-args setting (maxmem=) to reduce the recognised Ram. If set to 61440 it's ok.

Slow huh... How much recognized RAM does 61440 mean?
I dont care about energy bill. I live in north of Norway where power is cheap, and I am using like 10kw to keep the house heated anyway. Wouldnt mind having a Mac Pro heating up every room 😁

I just kept swapping them around until I got two pairs of 8 and two pairs of 4. Good enough. There was two sticks that seemed to be troublesome everywhere, so they went in the trash.

 

[Macschrauber]

Slow huh... How much recognized RAM does 61440 mean?
I dont care about energy bill. I live in north of Norway where power is cheap, and I am using like 10kw to keep the house heated anyway. Wouldnt mind having a Mac Pro heating up every room 😁

I just kept swapping them around until I got two pairs of 8 and two pairs of 4. Good enough. There was two sticks that seemed to be troublesome everywhere, so they went in the trash.

slow...

https://forums.macrumors.com/search/4327247/?q=maxmem%3D&t=post&c[child_nodes]=1&c[nodes][0]=1&o=relevance