MacPro RAM: 2x2GB + 2X1GB = 6GB OK?

[diazj3]

I just got my 2009 Quad 2.66Ghz.... Quick question:

To upgrade RAM, can I have 6GB in the following setup:

2 x 2GB sticks
2 x 1GB sticks (the ones that came with the computer)

I know RAM has to be in even numbers, but sticks must be in pair or triple sets for optimal performance?

Thanks!

 

[Cindori]

I believe the 09 uses triple channel so you'll benefit from using 3x of sticks instead of 2x.

 

[diazj3]

I believe the 09 uses triple channel so you'll benefit from using 3x of sticks instead of 2x.

Thanks Cindori... so to have 6GB it's better to get 3x 2GB... will the benefit of this triple channel hold if I get 8GB in 4x 2GB? or the optimal is 3x ?

And another quick question - can you recommend a fast (7200 rpm) & SILENT 1TB/32mb cache drive for my new machine? I'm between WD Caviars blacks, Hitachi or Samsung...

thanks again!

 

[Cindori]

you need 3x of modules for triple channel
if you need 8gb go maybe 1x1x1x + 2x2x2x ? memory is not my strongest side, get a second opinion


as for drives im hearing the caviar black. i have a spinpoint samsung though and I think it's silent.

 

[diazj3]

Thanks Cindori! I placed the order for 3x2GB and two Samsung drives (a 1TB for system & work, and a "green" 1.5TB as time machine backup and file repository...

I assume this "RAID-Class" drive can also perform as well under "non-RAID" configuration, correct? I want a fast, silent and highly reliable drive.

Also, I wonder if the ca. extra $50 are worth for the Spinpoint F1 drive, for being "enterprise/RAID-class" with 7yr warranty... vs the Spinpoint F3 with 3yr warranty.... what do you think?

 

[forester54]

how does this work if you want to add lots of RAM or even max it out since it only has 8 slots? 3x3x2?

 

[gugucom]

To make best use of the triple channel on the Octad you use only six slots instead of the eight. So depending of stick size you can have 6, 12, 24 or 48 GB.

The Quad would best run on 3, 6, 12 and 24 GB.

They should really have fitted 6 slots for the Quad and 12 for the Octad.

 

[Genghis Khan]

Just to clear the confusion about your RAM diazj3...

You have the Quad Nehalem Mac Pro. It is fitted with 4 RAM slots, yet utilises triple channel technology. This means that to get the fastest usage out of your RAM, you should install RAM in the first 3 slots only. However, if you find that you're getting frequent pageouts, it will be faster to put some RAM in the 4th slot (as slow RAM is still faster than a hard drive...).

Hope that helps
- Michael

 

[diazj3]

However, if you find that you're getting frequent pageouts, it will be faster to put some RAM in the 4th slot (as slow RAM is still faster than a hard drive...).
- Michael

Thanks Michael...

about pageouts, I'm not too familiar with the concept. I assume it's the blue area on the graph?... here is a screenshot of my activity monitor, the way RAM is about 75% of the time. Usually I have around 10-20% "free" memory at the end of the day before I shut it down (somehow used RAM is more as the day goes by)... Only 25% of my time I do what you'd call "intensive" work on it - and those times I have no problem in closing other apps to free up memory.

So I figured that - if on average I'm using 75-85% of the original 3GB RAM... getting (3x2GB sticks) 6GB (optimizing RAM with 3ple channel) will be enough to have 30-50% of RAM free on average days.... (thus, avoiding pageouts?)... does this make any sense?

PS. about the HDD questions: are these "server grade" F1 Samsungs worth the extra 50% markup price (being "server grade")? or should I go for the newer, less expensive F3 Desktop model? My computer isn't working 24/7... any thoughts about it?

Thanks! (as you can see, I'm a noob regarding MacPros)

 

[Cindori]

Paging occurs when the physical RAM is not enough and your computer is forced to use the hard drive to store the ram data.

what he means is that paging is slow, alot slower then what you lose if you drop triple channel. so if you get the pageouts, inserting just a gig or two of ram and losing triple channel is going to be faster since you get rid of pageouts.