Mixing Memory Modules

I just bought the MacPro with a 3.0ghz chip and let them ship with the standard two modules, 1GB each of 800 Pro 8-core memory. I bought (at 4 All Memory) four 2GB DDR2-800FB DIMM modules. Is there a reason not to leave the original two 1GB modules in place and just add the new memory?

If there are only two modules in the computer, one goes in slot 1 in each riser. Otherwise, matched pairs go in slots 1 and 2 of each riser, and when those are filled, in slots 3 and 4.
If the computer came with just two modules, one must be moved to slot 2 of the other riser when adding more memory. If it came with more than two modules, you don't have to move any. You will get best performance if both risers match, but don't remove modules just to make them match. More memory is always faster.
If you have four modules of one size, and four of another, put the larger in slots 1 and 2 of each riser, and the smaller in slots 3 and 4. Slots 3 and 4 are slightly slower, since their signals pass through the modules in slots 1 and 2. Putting the smaller modules in slots 2 and 4 means most memory will be in the faster slots.

Similar Messages

Mixing memory module of different sizes in G5-8 slot machine

is there a problem with Mixing memory module of different sizes in G5-8 slot machine
I have 2gb on four slots with 512 memory chips
Can I upgrade my memory with 1gb chips in the remaining four slots.

Hi epospiech-
Yes you can.
Instructions here: Memory (DIMMs) Replacement Instructions
Luck-
-DaddyPaycheck

Mixing memory modules of different sizes in a Mac Mini

I have a MM Intel Core Duo with a 1.66GHz processor and 512 MB 667 MHz SDRAM. Model Macmini1,1, 32 Bits, SMC Version (system): 1.3f4.
Anybody know if you can mix memory modules in it? I have the standard 256 modules (2) and would take one out and replace it with a 1 GB one. Can this be done?
Thanks

+Anybody know if you can mix memory modules in it? I have the standard 256 modules (2) and would take one out and replace it with a 1 GB one. Can this be done?+
Yes, you can do this. You will get a slight performance hit on video, but that will be more than offset 99% of the time by the extra RAM reducing overloading of the Virtual Memory system.
However, it is enough work to replace the RAM and RAM is cheap enough, that I'd recommend putting in two matched 1 Gig modules instead.

Mixing memory modules on Westmere

Dear Hardware gurus,
I have a 12-Cores Westmere. Do you know is it possible to mix different memory modules on it, namely:
6x1 Gb 1330Mhz
+
2x4 Gb 1066Mhz
and if yes, in which configuration?
Thanks a lot for any comment!

Kappy, thanks for the note.
I am actually going to order some more 1333 modules, but just for the short time I have to work with what I have currently (see my original post).
As I posted above, I tried a bit already to combine the modules and Mac doesn't boot
Can you suggest a configuration, which will work?

Can I mix memory modules?

I have some memory modules left over from various upgrades and I would like to use them to upgrade my daughter's iMac which is a 2.0 GHz machine using 667 MHz DDR2 SDRAM PC2-5300. I have 1 Gb of that memory from wife's iMac which is the same model but I also have 1Gb of 800 MHz DDR2 SDRAM 6400 from my own 2.4 GHz iMac. Can I install them together in my daughter's machine? If I can't mix them, will the 800 MHz run in it on it's own and would there be any benefit?
I also have some 667 MHz 5300 from my laptop which appears to be the same as that in the 2.0 GHz iMac. Can anybody confirm that? Finally, is there any risk in trying any of the above?
Thanks in advance
Ron

Teufelhunden,
Hi I know you're new so let me try to educate you a little. First is trying to ask a question in someone else's thread is considered rude, it's called thread jacking. I'm sure that wasn't your intent though. Next is if you see a green star by a thread that indicates it has been answered so posting a question in a thread that has already been answered probably isn't even going to be looked at.
I would recommend opening your own thread and I'm sure you will get some people more than willing to answer your question. If I see it I'll help you too! If you need assistance on how to create a thread click above where it says "Expanding your Intel-based iMac" and then you will see a link called *Post new Topic*.
Regards,
Roger

Mix memory modules

Hi,
I have two 2 GB memory modules that I pulled from my Mac Mini.
Since they are just sitting around, I am wondering if I add them to my iMac that has two empty slots, will give me any performance boost.
The iMac currently has two 8 GB memory modules.
Adding two the 2 GB would make the total go to 20 GB.
Will this help in any way?
Is there a certain order in which I should install these modules?
Thanks
Raj

We cannot say without know the exact model of the Mac Mini. Even though RAM modules may have the same form factor and number of pins, you cannot use RAM rated at a lower speed than that of your iMac's RAM.
You iMac requires 204-pin PC3-12800 (1600 MHz) DDR3 SO-DIMMs
Late 2012 and newer Mac Minis use the same RAM. If the Mini is older, the RAM will not work.

Would I be better off mixing memory modules in my iMac rather than just having 1GB unused?

I have a late 2006 20-inch iMac that currently has two 1GB 200-pin PC2-5300 (667MHz) DDR2 SO-DIMM modules installed. I recently bought two 2GB modules of the same type (different brand). Since I also have a macbook that uses the same type of memory (but 1GB total), I want to know how I can get the most speed with the momory I have for both computers (ie 4GB in an iMac that only recognizes 3GB and 2GB in the Macbook or 3GB in each). Thanks!

Matching 4GB in that iMac will give you a slight increase in preformance over 3GB.
see > Understanding Intel Mac RAM - Mac Guides

HT1423 Mixing Memory Modules

My iMac 27" can take up to 16g memory having 4 slots. Right now I have 4G memory installed (2x2g ram). Can I add 2 x 4g memory in the vacant slots? Thanks!

As long as the memory you get is the correct type it should not be a problem.

Is it right to mix sizes of memory modules in a mac mini 2012? for example 2Gb 8Gb?

Is it right to mix sizes of memory modules in a mac mini 2012? for example 2Gb 8Gb?

Welcome to the Apple Support Communities
You can do that without any problem, always that the total amount of memory is less than the maximum memory your Mac mini supports. A Late 2012 Mac mini supports 16 GB of memory, and you can find in this site the steps to install more memory > http://support.apple.com/kb/HT4432?viewlocale=en_US&locale=en_US#1

Experiences mixing DDR memory modules

Would you people post here experiences mixing DDR memory modules in order to help me/others take buying decisions?
I currently have a PC2100 256MB Samsung module and a MSI KT266 PRO2 and want to buy a new module.
As I cannot find one similar to the one I already own want to assign a success likelihood before taking my decision.
Thanks in advance Gustavo.-

Had a similar problem afew week's ago. I've got 2 identical stick's of 256Mb Samsung original DDR333 Cas 2.5, decided to upgrade to 1Gb and bought a stick of 512Mb Geil DDR333 (GL2000 Chips) Cas 2.5 for 45 quid. Installed the Geil in slot 2 (with the samsung sticks in slots 0 and 1) booted up o.k
bio's and windows detected the ram just fine.
After rebuilding the windows page file I started to test the extra ram by running 3dmark 2001 but kept getting BSOD's (Irq's less then..., Page faults in non ...etc) mid way through the test's. I went in to the bio's and relaxed the ram timing's to spd, no change. Increased the ram voltage's, no change.
So I thought I'd do a fresh install of windows, but 3/4 of the way through copying the files off the windows cd I kept getting 'can't copy xxxx file from the cd', tried cleaning the cd, tried a backup cd same problem, took the samsung memory out and just put the Geil stick in slot 0, the system wouldn't even boot, but with the samsung stick's in on there own window's installed o.k. I tried the Geil stick in another system, which booted up without a hitch. So finaly I just took the Geil stick out and gave it back, the suppliers tested it and found it to be o'k and charged me 20 quid for the privalage, Ba%&!%@s.
Last week I borrowed a stick of 512Mb Twinmos DDR333, same problem's as the Geil. Seem's like they don't make them like they used to and I'm doomed to 512Mb with this board.
AMD 2400XP @ stock
Akase 821 H/F
MSI KT4 SR with v1.3 Bio's
2x 256MB Samsung DDR333 Cas 2.5 @ stock
80Gb WD 7200 Hard drive on Ide 3
Plextor 40x CD Writter
16x Lite-on DVD
MSI Geforce 4 MX440
D-Link 10/100 NIC
Q-tec 450W PSU @ > 200W Combined
Windows XP with SP1

Satellite L20-101: Question about memory modules mixing PC2-4300 and PC2-4200

Hello
I have Toshiba Satellite L20-101. It has onboard 512MB RAM (PC2-4300). Today I added another RAM module but this new module is PC2-4200. Is there anything wrong doing this? Both modules are DDR2 and 533MHz and 512MB.

Hi Pawel,
In principle there is no problem with mixing RAM modules of slightly different types but normally the total RAM will only run at the speed of the slower module. If your notebook recognises the correct amount of RAM from both sticks then there will ne no problem.
regards,

Mixing RAM Modules (1gig + 2gig = 3gig)

Hello,
I am about to buy a Mac Mini and I am on a tight budget. The one thing I want to do for sure is upgrade the memory, but I'm in a quandary of sorts given my budget. The retailer where I want to buy the Mini from only sells the appropriate RAM for the Mini in 2gig modules. So here's my question: I know it is possible to mix the stock 1gig stick with a 2gig stick to get 3 gig of RAM total, but will it be worth it to me? I realize that the best configuration would be to slap in 2 2gig modules in and just be done with it, but with 3gig, would I be appreciatively shooting myself in the foot and killing the machine's performance, or wouldn't I notice? I need to have the memory installed at purchase because I am physically handicapped and adding the memory myself is out of the question. And after researching how to replace memory on the Mini, I wouldn't have the courage to ask anybody I know to attempt to do it after buying it. Is mixing RAM modules a good idea?
Thanks in advance.
Malcolm

Nope, I am not confused, There does have generation between Mac mini model. Maybe not official, but we all know. Check About This Mac ---> More Info ---> Model Identifier : Macmini2,1 (That means, 2nd generation)
Macmini 3,x (means 3rd generation I supposed)
And the 3rd generation doesn't support Dual Channel, referred to Crucial.com
http://www.crucial.com/store/listparts.aspx?model=Mac%20mini%20%28Intel%20Core%2 02%20Duo%202.0GHz%20DDR3%29%20MB463LL/A&pl=Apple&cat=RAM

Mixing Memory Speeds

Apologies, wrong thread, please ignore.
Message was edited by: Rhys Bethell

Hi Rhys,
i think what you are talking about is mixing memory size, not speed. You can not mix memory speeds, especially in Macs.
You can mix memory size in most Macs. Very few Macs use memory interleaving that requires exactly the same size memory modules to work best. The iMacs allow mixing size with no impact on performance.
Go ahead, Crucial is very good with Macs and can be trusted.
Also very good is Other World Computing (OWC).
Ralph

Mixing memory size

Is it possible to mix different memory module sizes in an iMac 2010¿ I currently got the standard 2x2gb installed, but would like to add 2x4gb, making the total 12GB. Is this possible?

yes, thats fine.

How to test 'Matching' memory modules - iMac G5 (ALS)

Hi there,
Does anyone know of a way of checking whether memory modules are working at 128-bit rather than 64-bit?
For reasons of cost and availability, I have installed two 1GB DIMMs from different manufacturers in my iMac G5 (ALS).
As per the Apple article:
http://docs.info.apple.com/article.html?artnum=300082
The specifications seem to be matching ie, they are both:
184-pin
Non-EEC
Unbuffered
PC3200U-30330
CL3
16 devices
So, in theory, they should be working at 128-bit in dual-inline mode. System Profiler just says they are both 1GB PC3200U-30330 modules and that they are both OK.
So is there a way of telling for definite...out of interest...my computer seems a bit nippier but that could just be the increase in RAM from 1.5GB to 2GB.
??

So, when ordering RAM, what's the trick to ensure you get matched 128-bit
capability? I missed the "gotta have stats".
From my experience, the biggest issues are:
1) same number of components (same chip count front and back)
2) same CAS latency
for example, in the numbers: PC3200U-30330
the first "3" in 30330 is the CAS latency. The other numbers after that can be different, but you want the CAS latency to be the same. I don't know what the other numbers mean.
PC3200 is just the type. Most likely you have the same type. Otherwise, you'd have other problems.
I've purchased, mixed and matched, and installed several different modules, and as long as they were the same CAS latency and chip count, they registered as "matched".
You can check the numbers for your modules by going into system Profiler, and clicking on the "Memory" in the list on the left.
System Profiler is in: Apple Menu --> About this Mac --> More info.
Hope this helps.

Mixing Memory Modules

Similar Messages

Maybe you are looking for