Mac Pro, Adding More Ram

[Help!]

I have an incoming Mac Pro with 1gb (2x512) of ram and I would like to get more. I am thinking of getting an additional 2gb (2x1gb), will this work well or is it a necessity to have 4 matching (for example 4x512)?

 

[CanadaRAM]

I have an incoming Mac Pro with 1gb (2x512) of ram and I would like to get more. I am thinking of getting an additional 2gb (2x1gb), will this work well or is it a necessity to have 4 matching (for example 4x512)?

It is not necessary to have 4 matching. 2 x 1 Gb would be a good choice.

 

[Transeau]

You can add them in matched sets of 2 or 4, depending if you want Dual or Quad channel. Dual Channel is just fine for most users, Quad channel is desirable for users running memory intensive applications.

 

[Help!]

Thanks!

 

[strieck]

You can add them in matched sets of 2 or 4, depending if you want Dual or Quad channel. Dual Channel is just fine for most users, Quad channel is desirable for users running memory intensive applications.

You don't need a matched set of four for quad channel. Having one matched pair on both of the riser cards will give you a quad channel configuration. http://barefeats.com/quad09.html

 

[Transeau]

Their info isn't exactly detailed and accurate.

Being an engineer (Yes, I actually do design motherboards too) I can assure that you to have the Mac Pro in Quad Channel mode, you do indeed need a matched set of 4 FB-DIMMS. By matched pair, I mean 4 DIMMs of the same capacity and chip count. The same manufacture is not needed. The system will deal with miss matched CAS and SPD. (choosing the fastest that all DIMMs can run at)

The key to Quad channel mode is capacity and chip count. (Chip count doesn't really matter right now, as there are so few FB-DIMMs available, most all have the same count)

I can assure you that putting 1GB DIMMs in A1 and A2 and 512MB DIMMs in B1 and B2 WILL run the memory at 128-Bit (Dual Channel) and NOT 256-Bit (Quad Channel)

 

[Grimace]

Why don't you use a quad-channel configuration then? (from your sig, it shows you have 6GB.)

 

[Transeau]

Why would you assume I do not use quad channel?

4x 1GB & 4x 512MB = 6GB

I don't think you need to be an ass about it. I was trying to point out the technical facts and help a new user. If you disagree with the info I posted, you can either do what you want, or go to Intel's support site and read the documentation on the 5000X chipset.

Here is the PDF on the chipset. The memory info starts on page 306.
http://download.intel.com/design/chipsets/datashts/31307003.pdf

 

[strieck]

Here is the PDF on the chipset. The memory info starts on page 306.
http://download.intel.com/design/chipsets/datashts/31307003.pdf

Thanks for posting the link. I browsed the memory info, but I don't see any reference to Dual or Quad channel. However, the sections on non-mirrored and mirrored upgrades seem relevant to what we're discussing here. Am I correct in assuming that non-mirrored mode is what we are calling Dual channel and mirrored mode is Quad channel?