Choosing the right ram

[121]

Hi
I just bought a Mac Pro. It only has 4GB installed on it. I was going to upgrade ram but i came across a problem.

The pre-installed ram is 4x1GB 667 ECC DDR2 FB DIMM according to system profiler. I said to myself fine, this is 667 mhz ram but while looking at the serial of my mac i saw it was an early 2008 (april) Mac Pro 3.1
and those machines need 800 mhz according to various sources. System profiler also says this is a Mac Pro 3.1
It would be a sure bet to get 667 mhz ram but I'd like to get 800 mhz for better performances. SO what shall I get ?

Thanks

 

[prestonkd]

You need the 800 MHz RAM. Here is a link to the memory sales page on OWC which has the memory broken down by machine, model, year number, etc.
http://eshop.macsales.com/shop/memory/Mac-Pro-Memory
I have the same year Mac Pro and have bought RAM here. Works great and is indistinguishable from the Apple RAM- at least to me.

 

[121]

ok thanks!
How is it possible that the Mac Pro is running 667mhz ram right now?

 

[Umbongo]

ok thanks!
How is it possible that the Mac Pro is running 667mhz ram right now?

Because it supports both types as it is newer. They all support 533MHz too. It just runs slower.

 

[121]

all right thanks! just got 16GB 800mhz for 388 shipped.

 

[Spacedust]

Hynix, Micron works are the best.

One of my Micron sticks died few months ago and I replaced it work Hynix. All working fine

Samsung is ok too, only Qimonda didn't worked properly.

 

[mongeta]

What happens if you mix differents speeds?

A friend of mine has a MacPro '08 with 2gb at 667 and wants to add more ram, the 667 is cheaper than the 800, but slower...

If you mix it all 800 goes down to 667 ?

Just curious...

thanks,

 

[Umbongo]

What happens if you mix differents speeds?

A friend of mine has a MacPro '08 with 2gb at 667 and wants to add more ram, the 667 is cheaper than the 800, but slower...

If you mix it all 800 goes down to 667 ?

Just curious...

thanks,

If it works (should do) it'll go down to 667.

 

[mongeta]

If it works (should do) it'll go down to 667.

Ok, thanks, so it's better to buy ram for the current module's speed, in this case 667

 

[nanofrog]

Ok, thanks, so it's better to buy ram for the current module's speed, in this case 667

Under the given conditions (mixed frequencies after the upgrade and the 667MHz is cheaper), then 667MHz is the more cost effective way to go.