MP RAM: 1GB X 4 combined with 2GB X 2?

[valdore]

I'm wondering if I made a serious mistake here. I just ordered more RAM for my Mac Pro, 4 GB total with 2 sticks at 2 GB each.

Then I thought to check "About this Mac" and it says I have 4 sticks at 1 GB each.

Will I be able to have 2 sticks of 2GB RAM right along with 4 sticks of 1GB RAM? Or do I need to cancel my order?

Thanks.

 

[ktbubster]

I don't own a mac pro... but to my understanding and what i've read on here, that's fine as long as you have the slots available. I see a lot of people with 2 by 2 and another 1 for a total of 5 so I don't see why more would make a difference.. 8gb of ram is gonna be nice!

 

[Serge N Gin]

I'm wondering if I made a serious mistake here. I just ordered more RAM for my Mac Pro, 4 GB total with 2 sticks at 2 GB each.

Then I thought to check "About this Mac" and it says I have 4 sticks at 1 GB each.

Will I be able to have 2 sticks of 2GB RAM right along with 4 sticks of 1GB RAM? Or do I need to cancel my order?

Thanks.

Just found this so I thought I'd share it with you valdore:

How do I install RAM in the Mac Pro?

The Mac Pro has two small riser cards, each of which contains four FB-DIMM slots. To install RAM, you slide a riser card out and set it down on a flat surface. (The bottom of the riser card contains plastic feet so that the circuit board itself doesn’t make contact with the surface to place it on.) Then you install the memory modules—always in pairs of the same capacity from the same manufacturer. You need to install pairs of RAM in the proper order, which is printed on the inside of the Mac Pro door: a pair in the top two slots of the top riser, then in the top two slots of the bottom riser; then in the bottom two slots of the top riser; and finally in the bottom two slots of the bottom riser. When you’re done installing RAM, you slide the riser card or cards back into the Mac Pro until they re-connect with the motherboard.

Apple includes two 512MB modules in the stock configuration. As with the Power Mac, the Mac Pro requires matched pairs of RAM to function. To max out the RAM, you’d need to install 2GB modules in each of the Mac Pro’s eight RAM slots. That’s a lot of RAM.

 

[valdore]

Thanks for the replies guys. Additionally, I found this in the FAQ at OWC's site:

http://helpcenter.owc.net/index.php?x=&mod_id=2&root=5&id=318

G5s and Mac Pros require matched pairs. These are chips that are from the same vendor and batch of chips to ensure they are exactly the same. When installing the new memory chip pairs you need to make sure that the similar chips are placed in the same set of slots per pair. Your Apple manual should help determine the pairing layout of your machine model.

A common question is can you mix the sizes of your chips. Yes, you can have for example a pair of 512s and put in a pair of 1GB chips in the next slot pairing if you would like to. As long as they are paired up with their like chip they will work fine and in the above example would bring your machine up to 3GBs total.

...so I guess I'll be okay.

 

[Boemer]

Xeon 256bit

According to what I read, if you want have the maximum memory speed, you need 4 chips, to reach 256bit access.

You can look at the apple-store, if you configure a mac pro, and play with the memory option. When you choose 2 GB, it will give you 4 x 512MB.

When you choose 4 GB, instead of getting 2x 2GB, so you can easily append a few later, Apple is giving you 4x 1GB.

So having 4x1GB is okay, you have maximum memory access, adding those 2x2GB is probably not optimal, but it will work. And when you have extra money later or need more, than you can buy an other 2x 2GB, and you have the optimal speed again.

If you're still running Tiger, because of 32bits, you probably won't have any advantage of more than 4 GB. A friend of mine, said he couldn't use those extra Gigabytes... (He is still running Tiger...)

 

[valdore]

I'm on Leopard now, which I have noticed tends to gobble up memory a little bit more than Tiger did. But my primary reason for wanting more RAM is because I use Aperture a lot, which is a complete memory hog. Photoshop can be almost as bad sometimes.

 

[netnothing]

Here are the suggested layouts.

-Kevin

 

[valdore]

Here are the suggested layouts.

-Kevin

Thank you. Took me a minute to decipher it but I now know exactly where to place everything when the new RAM arrives.

 

[netnothing]

Thank you. Took me a minute to decipher it but I now know exactly where to place everything when the new RAM arrives.

As you can see you want to make sure you put the largest DIMMS closest to the motherboard. So your 2 X 2GB will sit alone on the top Riser, slots 1 & 2.

-Kevin

 

[akadmon]

I bought my MP with 4 512Mb modules from Apple and filled the rest of my slots with 1 Gb modules . I keep hearing that's not optimum, but I'd be damned if I'd be able to notice the difference. And frankly, it's all just talk anyway -- I haven't seen any real world data showing that a MP configured the way mine is is any slower than one configured with same size modules.