8 vs 6 memory slots 2010 MacPro

Hello Ultimeter,

i myself would never think about ram speed. Its influence on overall system speed / performance is much too low.

Yes, it can be measured, but the tests (made by c´t a german computer magazine) i have seen only show difference that are in a range of only a few percent.

In an average day of working with a computer you dont "feel" or "see" the difference. Only when you do strong number crunching, have big pictures to edit, and as Grant has already said, when your ram usage is bigger 70, 80 gb, and you see a red ram presure bar, it really is recommended to install all slots to have 128gb.

But when you have 128 gb in your system, and your audio jobs don´t have any drop outs, simply leave all ram slots installed. I personaly feel better having some reserve.

Yes, unused ram is wasted ram, it eats more electric power, gives more heat in your system, wastes money. But it feels good ;-)

I use the 128 gb of my mp 5.1 for gigapixel stitching: http://360.haifischbar.de/panoramen/beispiele/w3d/skyjumpwuppertalFP.html?s=pano137

(try to zoom in!)

greetings from gemany

Chris

That Mac Pro is optimal with three slots on each side filled with matched-size modules. Slots 3 and 4 (on each side) are shared, and populating slot 4 may increase Bus Loading, and can cause overall memory timing to step down once click, as you saw.

Use Activity Monitor to look at various usage while running your most demanding work flow. The Memory pane can be most enlightening. But remember, the MacOS mantra from Mavericks forward is, "unused RAM is Wasted RAM" so memory filled up is normal.

What is a cause for alarm is a Memory pressure graph that ever turns RED.

How to use Activity Monitor on your Mac - Apple Support

Most Users contemplating a Processor upgrade are shocked to discover their CPU usage is extremely low (unless they are running Compressor). RAM shortages and slow disk access and bad disk organization (not having different kinds of stuff, like sound libraries, on a separate drive) contribute far more to overall slowness.