Memory upgrade for Intel Xeon Mac Pro?

October 22, 2009 9:12 PM

Memory upgrade for Intel Xeon Mac Pro?

I bought the base mac pro a few months ago planning to up the memory right away. When I went to do this I got confused by a few websites that warned about using only certain kinds of memory and in certain groups. Can someone tell me what they think is the best way without spending more than necessary?

The computer is a 2.66 Quad-Core Intel Xeon with 3 GB 1066 MHz DDR3.

Thanks!

posted by austinlee to computers & internet (7 answers total)

For Mac Memory, I swear by http://www.crucial.com - they may not be the cheapest out there, but they make quality memory designed specifically for your system that is guaranteed to work. When you punch in your make & model of computer (Mac or PC), they not only tell you what kind of memory to get, but how many slots are in your computer, limits, etc. They even have a scanner that will determine the correct type for you.

You can always use their site / scanner to get the specs, and order the memory elsewhere, but Crucial's memory has always done well by me in both personal and business environments.
posted by GJSchaller at 9:36 PM on October 22, 2009

You need ECC SDRAM.
I believe it was true in the past that having all four slots filled will improve overall memory performance, since it has some kind of a quad-channel memory bus, but I'm not positive that's true with the current generation.
posted by demiurge at 9:51 PM on October 22, 2009

Crucial is good, yes. I have also had good success from OWCC, which also has a "pick your exact model and we'll show you the RAM that is correct" style interface.

Good prices and reliable, too: I first ordered from them in, like, 1992.
posted by rokusan at 11:37 PM on October 22, 2009

Thanks for your suggestions. Part of my question was about the memory configuration. Can I just add a 4 GB stick to the empty slot?

OWC warns on their site
"OWC p/n OWC8566D3MPE4GB 4GB modules require that all installed modules be of this same matching part. Other existing Apple or 3rd party 1GB, 2GB and 4GB modules are not supported for use with this kit and need to be removed when this kit is added."

site so its clearly discouraged but will it still work?
Is it dangerous to do this or is it just not recommended?

What would you guys suggest with the current configuration of 3 1GB sticks in the machine? Should I just wait until I can afford to make a big upgrade or should I try to throw an extra stick in for a little extra boost?

Thanks!
posted by austinlee at 7:06 AM on October 23, 2009

Also I saw this on Crucial I could get 4GB in two 2GB sticks. I think I read that you have to upgrade in pairs so maybe I could put these two in and get rid of of one of the 1GB sticks. That way I would have 2 1GB sticks and 2 2GB sticks. Will that work?

http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=C309EEA9A5CA7304

Thanks!
posted by austinlee at 7:14 AM on October 23, 2009

According to Ramjet

The DDR3-1066 DIMMs for the Mac Pro require an EPROM Thermal Sensor for full performance and compatibility. Many 3rd party Mac Pro DIMMs not include this sensor. However, Ramjet memory always conforms 100% to the Apple spec, and these DIMMs do include the thermal EPROM.

The DDR3-1066 DIMMs for the Mac Pro will run 5-10% faster if they are installed in matched sets of three (tri-channel). You may add DIMMs in any combination, but perforance will suffer slightly if the DIMMs are not matched 3x at a time.

When installing 4GB DDR3-1066 DIMMs into your Mac Pro, ALL installed memory must be the same matching 4GB part.

So, it looks like you cannot just add a 4GB to the last slot, but you could put in 2 2GB sticks replacing one of your 1GB sticks, but you will have a slightly lower performance. Perhaps you can get 3 2GB sticks and replace all the 1GBs.
posted by nightwood at 11:11 AM on October 23, 2009

nthing Crucial.
posted by kenliu at 3:51 PM on October 23, 2009