Question about Upgrading Early 2008 Mac Pro Memory

[markw10]

I have an early 2008 Mac Pro running OS X Lion. It currently has 8GB of memory which consists of 4 memory modules of 2GB each, 2 on each of the memory cards.

I really want to go to 32GB but likely will go to 16GB. I do a lot of virtualization using VMWare often running Windows and Linux partitions so I think the additional memory will help a lot.

I plan to purchase from OWC which is where the memory I currently have is from but I see two options.

One is to buy 4 more of the 2GB memory modules which would then fill all slots and total 16GB and the total cost would be $241.

Another option is to buy 2 of the 4GB modules. The cost would be slightly more at $275.
-Would there be any advantages to this?
-Does it cause any issues and am I better off using all 2GB modules for example so that they match?
-One reason I prefer this option is although it costs slightly more if I'm correct that would leave 2 slots open where I could later upgrade with another 2 4GB modules for 24GB total.

Another option is am I better off (performance and price wise) simply starting over, getting all new memory. I can pay $549 and get 16GB (4 4GB modules) I know I could keep the current 8GB for 24GB total but again I don't think I need that much but I guess my question is, if I go with the 4 4GB modules and then get rid of the current 4 2GB modules would I get more performance using 4GB instead of 2GB modules. Also, I know OWC buys memory but I am assuming my best bet is eBay and if so, would I save money by getting the 4GB modules (4 of them) and then selling my current memory on eBay?

Thanks for your help with the above questions.

Mark

 

[Gomff]

I have an early 2008 Mac Pro running OS X Lion. It currently has 8GB of memory which consists of 4 memory modules of 2GB each, 2 on each of the memory cards.

I really want to go to 32GB but likely will go to 16GB. I do a lot of virtualization using VMWare often running Windows and Linux partitions so I think the additional memory will help a lot.

I plan to purchase from OWC which is where the memory I currently have is from but I see two options.

One is to buy 4 more of the 2GB memory modules which would then fill all slots and total 16GB and the total cost would be $241.

Another option is to buy 2 of the 4GB modules. The cost would be slightly more at $275.
-Would there be any advantages to this?
-Does it cause any issues and am I better off using all 2GB modules for example so that they match?
-One reason I prefer this option is although it costs slightly more if I'm correct that would leave 2 slots open where I could later upgrade with another 2 4GB modules for 24GB total.

Another option is am I better off (performance and price wise) simply starting over, getting all new memory. I can pay $549 and get 16GB (4 4GB modules) I know I could keep the current 8GB for 24GB total but again I don't think I need that much but I guess my question is, if I go with the 4 4GB modules and then get rid of the current 4 2GB modules would I get more performance using 4GB instead of 2GB modules. Also, I know OWC buys memory but I am assuming my best bet is eBay and if so, would I save money by getting the 4GB modules (4 of them) and then selling my current memory on eBay?

Thanks for your help with the above questions.

Mark

I have the same machine as you which I upgraded from 8GB to 18GB about 6 months ago.

From the advice I had at the time, there are marginal performance improvements to be gained by certain memory configurations but to be honest I didn't think them worth the time or money.....Especially since memory for these machines is already pretty expensive.

All my slots are full....I have 4 x 2GB sticks in one daughter board, and 2 x 4GB + 2 x 1GB in the other. I don't foresee that I'll be upgrading beyond 18 GB so this works fine for me.

I would say that if you're certain that you'll want more memory later, go for the 4GB sticks and leave the others in until you want to upgrade but that will give you 24GB which is quite a lot to be getting on with.....You may find it's enough perhaps?

 

[kevink2]

I would recommend buying 2 4GB modules. You still have the option to expand later without replacing memory.

I'm at 14GB because I bought the computer with 2GB. Bought another 2GB (and was shipped 4GB of 1GB chips). Then later I bought 8GB.

 

[Bwa]

I'd go with the 2x4gb as well. I have the same machine; started with 12gb in 2008, later went to 24gb and then to 32.

One thing to keep in mind, which I am sure you have considered, is how much longer are you going to use the machine. But given its only $30 more to keep two slots free, I see no downside to going that route.

 

[ekwipt]

Fill all the slow slots for the fastest bandwidth in a 2008, i don't need more than 16gb so thats what i did, filling less will slow slow the ram.

2008 8 slots
2009 multiples of 2, so 4, 6 or 8
2010-2011 6 slots
2012 4 slots so 4 or 8

 

[kevink2]

Fill all the slow slots for the fastest bandwidth in a 2008, i don't need more than 16gb so thats what i did, filling less will slow slow the ram.

2008 8 slots
2009 multiples of 2, so 4, 6 or 8
2010-2011 6 slots
2012 4 slots so 4 or 8

Can you even notice the difference in speed between 16 GB in 6 slots or 16 GB in 8 slots?

In anything but a synthetic benchmark?

 

[Umbongo]

Can you even notice the difference in speed between 16 GB in 6 slots or 16 GB in 8 slots?

In anything but a synthetic benchmark?

It's 7.5GB/s vs. 6.5-7 GB/s so no you aren't going to notice really. You won't notice a lot of small performance increases with hardware - in the sense that if you had a slightly faster thing you aren't going to feel that was enough when it wasn't before. It does increase performance though. Can't really measure it in real terms.

 

[kevink2]

It's 7.5GB/s vs. 6.5-7 GB/s so no you aren't going to notice really. You won't notice a lot of small performance increases with hardware - in the sense that if you had a slightly faster thing you aren't going to feel that was enough when it wasn't before. It does increase performance though. Can't really measure it in real terms.

And then only when the data you are interested in is in the correct memory banks.