Is 5gb (2x2gb+ 2x512gb) possible?

[crx00]

I have a 2.66 ghz quad core mac pro with 1 gb (2 x 512mb) ram. Thanks!

 

[dukebound85]

I have a 2.66 ghz quad core mac pro with 1 gb (2 x 512mb) ram. Thanks!

as long as you have 4 ram slots which you do im pretty sure it would work. no reason not too

make sure they are all the same speed though

 

[Topper]

Is 5gb (2x2gb+ 2x512gb) possible?
I have a 2.66 ghz quad core mac pro with 1 gb (2 x 512mb) ram. Thanks!

Yep.

 

[crx00]

Yep.

thanks! off to OWC I go

 

[Mackilroy]

Yep.

When I tried that in my Mac Pro it only recognized the two 512MB modules.

 

[TEG]

Wouldn't you need to have one of each on each riser?

TEG

 

[ungraphic]

Wouldn't you need to have one of each on each riser?

TEG

Thats what i heard, that the ram works best when in pairs and in the same configuration on both riser cards.

 

[darthraige]

And to triple confirm, my boss' MacPro (same one has you) has 5GB of ram in it.

 

[Inconsequential]

Wouldn't you need to have one of each on each riser?

TEG

I believe that is correct as each riser is its own channel IIRC

 

[CanadaRAM]

Wouldn't you need to have one of each on each riser?

TEG

No, RAM must go on risers in pairs -- A1 A2 have to be matching
B1 B2 have to be matching.

Apple delivers the new Mac Pros with 1 Gb FBDIMMs in A1 B1 but you have to move those into paird slots (1 and 2) to add any new RAM

Thats what i heard, that the ram works best when in pairs and in the same configuration on both riser cards.

Pairs on a riser is mandatory -- matching 4 modules across both risers is optional, it gets a small improvement with quad-channel access.

 

[TEG]

No, RAM must go on risers in pairs -- A1 A2 have to be matching
B1 B2 have to be matching.

Apple delivers the new Mac Pros with 1 Gb FBDIMMs in A1 B1 but you have to move those into paird slots (1 and 2) to add any new RAM

Pairs on a riser is mandatory -- matching 4 modules across both risers is optional, it gets a small improvement with quad-channel access.

That doesn't make sense, since each riser must have the same amount of RAM, because the channel extension is done on each slot on the logic board, and therefore each riser must contain the same amount of RAM.

TEG

 

[Infrared]

I have a 2.66 ghz quad core mac pro with 1 gb (2 x 512mb) ram. Thanks!

I would say so. One in the Apple shop had 5GB in it.

 

[CanadaRAM]

That doesn't make sense, since each riser must have the same amount of RAM, because the channel extension is done on each slot on the logic board, and therefore each riser must contain the same amount of RAM.

TEG

Your original premise is wrong. The risers do not have to have the same amount of RAM.

If the A1 A2 B1 B2 pairs have the same RAM sizes, then you get 256 bit access across those slots.

 

[xraydoc]

That doesn't make sense, since each riser must have the same amount of RAM, because the channel extension is done on each slot on the logic board, and therefore each riser must contain the same amount of RAM.

TEG

Not correct. They only have to be installed in pairs. First, pair A1, then pair B1, then pair A2, then pair B2.

 

[Infrared]

No, RAM must go on risers in pairs -- A1 A2 have to be matching
B1 B2 have to be matching.

Apple delivers the new Mac Pros with 1 Gb FBDIMMs in A1 B1 but you have to move those into paird slots (1 and 2) to add any new RAM

So is the 2xFB-DIMM case the only one where you can have
RAM paired across different risers?

Pairs on a riser is mandatory [...]

Except, apparently, when Apple shoves 2 1GB sticks in there

Really, I would like to know why there is this special case. Thanks.