RAM in a mid-2009 Mac Pro 8 core

[Henry]

A question for those of you are using more RAM in their Macs. I currently use 8 GB of RAM in 4 ports of 2GB modules, but now that RAM has at last come down in price, I'm thinking of adding more.  I could add an extra 4 x 2GB modules for about £100, or 4 x 4GB modules (Crucial) at about £200.  My question is, would I notice an appreciable speed increase by going to 24GB over 16GB?  Many thanks in advance.

Henry

[alexkent]

personally i have 12GB in a 2010 8-core MacPro, i regularly edit ~2GB images in CS5 whilst processing shots in Phocus, listening to iTunes etc. and i rarely 'run out' of ram.

upgrading to 16GB is probably worthwhile, but i don't know whether 24GB is worthwhile.
maybe if you're editing much bigger files in Ps you might notice a difference between 16GB and 24GB...
i will be investing in SSD disks before more RAM.

regards, Alex.

[Phil G]

Hi Henry

Depends how many applications you want to open at any one time and you need to be running 64bit Snow Leopard

Many applications like Aperture and Phocus  use the video ram on the graphics card so you probably wont see much difference in screen rewrites well not as much as changing your card as the chipset on it is important  I changed from a 512MB standard card to a 512MB  ATI Radeon HD 4870 and there was a marked improvement  

I upped my Mac Pro  recently removing the suppled 1GB ram sticks with 4GB  (do you know any one who needs any 1GB 800MHz sticks) I have a few 2GB sticks in the slots but I don't think its worth changing them  18GB  seems adequate for my needs

Phil

[Dustbak]

I use 24Gb (6x4Gb). I never run out of memory. Good thing to remember is that the Nehalem has a triple channel memory bus., eg. 6 banks will outperform 8 banks of memory being used unless you run out of memory and the OS needs to start using scratch disk.

If you are sure you will not run out of memory you better only fill up the 6 banks of your MacPro and leave the last 2 banks empty.

[Henry]

Alex,  Many thanks for that - 16GB looks sensible
Phil, You are so right about the graphics card - I specced that one at build after consulting Hasselblad, and it makes a huge difference!
Ray, Good point I'd not considered.  I'll probably go for 2x4GB sticks to bring me up to 16 overall - I can always get another 2 later if I'm running low on RAM. Do you recommend putting the 4GB sticks in slots 1 and 5, or will 3 and 7 be fine (leaving the 2s in place)?

Many thanks again to all for such a speedy reply - it's greatly appreciated.

Henry

[Dustbak]

I would recommend putting them in 1 &5 however your MacPro will tell you what the optimum place is  when you put it in a place less optimal. Just keep it to 6 banks.

[Henry]

Many thanks again, Ray - I'll do as you suggest.
Henry