[robbodobbo]

Hi guys!

In your expert opinion, would I see a real advantage of a 2.66 over a 2ghz mac pro. I will be using logic, plug ins, FCP & Motion etc in my studio. Would a load more ram be more beneficial than chip(s) speed?



Thanks in advance.
RH.

[mduell]

While I would suggest buying a couple gigs of RAM for that type of work, the downgrade from 2.66 to 2.0 is really hard to stomach. The difference in the cost of the chips is about $800, but Apple only gives you back $300 for taking the downgrade.

If you're doing a lot of Motion and/or Motion on HD content, I'd recommend the X1900XT graphics.
Take the downgrade from 250G->160G for $75. You can turn around and buy a 250G drive for about $75-80 or 320G for $90.

So I suggest 2.66Ghz, 1GB RAM, X1900XT, and 160GB disk from Apple. Buy a disk or two (if you need them and don't already have disks to move over from another machine) from Newegg, and the 2x1GB or so from Crucial once they're shipping memory for Mac Pros (which I'm guessing will be about the same time the X1900XT equipped Mac Pros ship from Apple).

[moodymonster]

I've read that the memory is best installed in groups of 4, makes it go faster, uses a wider bus?

so if you're going for 2GB - using 4x512MB chips might give a performance increase

just had a quick google -> http://www.anandtech.com/mac/showdoc.aspx?i=2811&p=5

There are a couple of things you can do to maximize performance and minimize the cost of additional memory on your Mac Pro, and it starts with the number of FB-DIMMs you configure your system with. The Mac Pro ships with a default configuration of 2 x 512MB FB-DIMMs, unfortunately that means that you're only using two of the four available memory channels, cutting your peak theoretical memory bandwidth in half. You'll want to upgrade to at least four FB-DIMMs so that you can run in quad-channel mode, in the coming weeks we'll be running some tests to figure out exactly how much additional performance you'll gain by doing that and if it's noticeable or not.

If you do find yourself filling all 8 memory slots on the Mac Pro, we would suggest trying to move to 4 higher density modules instead. Remember that you gain an additional 3 - 5ns of latency (at minimum) with each FB-DIMM hop, so the fewer FB-DIMMs you have the lower your worst case scenario memory latency will be. But since you still want to be running in quad-channel mode you don't want to drop below four FB-DIMMs, making four the magic number with the Mac Pro.

not to do with processors, but...

[mduell]

Originally Posted by moodymonster

I've read that the memory is best installed in groups of 4, makes it go faster, uses a wider bus?

Yes. With any less than four, you're not using all the channels, so you're not getting all the bandwidth. However with any more than four, you'll noticed some increased latency (at least 3-5ns) when accessing the second module on a channel.
As far as I can tell they do not need to be symmetric, so 2x512M and 2x1G is fine.

[moodymonster]

Originally Posted by mduell

As far as I can tell they do not need to be symmetric, so 2x512M and 2x1G is fine.

I was wondering about that bit.

[SierraDragon]

Originally Posted by robbodobbo

Hi guys! ...I will be using logic, plug ins, FCP & Motion etc in my studio..
RH.

You are professionally using heavy pro apps The more pro a box you configure, the better the life cycle cost.

Certainly 2.66 GHz as a minimum and X1900 XT graphics. If cash is tight you could try the stock 7300GT graphics now and add a more powerful graphics card later, but I would recommend against the 2.0 CPU reduction.

Odds are you will want to exceed 8 GB of RAM during the life of your new box. You only have 8 RAM slots, so plan accordingly. IMO whatever small gains may occur from 4x512 symmetry, they are not worth a major waste of slots! If cash is tight just start with Apple's 1 GB initially then add (ideally 2 GB modules) RAM later when prices fall. I will either order 4x2 GB from Apple or retro add 2x2 GB to the stock 2x512. So far Apple's ECC RAM is only a small bit more than third party.

-Allen Wicks