CS4 Not Seeing All Cores

Question

AE CS4 is only "seeing" 4 of the 8 available cores in the Preferences/Memory & Multiprocessing Menu.
However during stress test rendering, all 8 cores show activity in Task Manager/Performance.
Any ideas?
Many thanks, Linda
i7 PC base unit, inc i7-920 CPU, 6GB RAM, 500GB system disk, 1TB data disk (plus 2x eSATA ports for external disks), DVD-RW, BluRay-RW, 896MB 275GTX graphics card, Vista 64 Business, Matrox RTX2 card, CS4 Production Suite

Answer 1

Ok, perhaps I'm looking at this the wrong way.
I need some memory help.
I wrote the following on the Premiere forum, but got no answer. You're both quick to respond, so please can you read this, as my problem is a mix of AE & Ppro.:
Using a new cs4 system, I start a new 1080i project.
I dynamically link to a new AE file. Within the AE file I put one 4mb jpg running over 20 seconds, and save.
Back to Ppro, I put the AE comp on the timeline.
At this point, Task Manager shows that PPro is using around 0.5 gb ram.
I render the 20 seconds of the Ppro timeline which has the AE clip.
After rendering, Task Manager shows PPro as using almost 2GB ram.
But this ram doesn't seem to get freed up again... so after a few minutes more working, I start to get ram warning messages.
Soon after, Ppro shuts down.
I've tried changing the "Optimise rendering for Performance / Memory, in Ppro, but this doesn't have much effect.
So - I've got a new system with loads more memory than my old XP cs3 system - yet the performance in PPro & AE is nothing like as good.
After rendering, I can save, close and open the file again - it's marked green for rendered, and the memory is back to 0.5gb.
But I shouldn't have to close the programme between every render, I'm sure.
Background info and rant: this was a new system which was delivered to our studio last week.
Eventually tearing my hair out this afternoon, I've written to the pc builder saying I want to return it, and to Adobe asking to return CS4.
But if you can solve this problem I'll happily go back to them both and say it's fixed.
I wrote on the Support forum, which says I'll get a reply in 3 days.
I phoned support three times, each time being put on hold for 20 minutes before being cut off.
So suggestions very welcome to get what should be an awesome system up to scratch.
Many thanks, Linda
i7 PC base unit, inc i7-920 CPU, 6GB RAM, 500GB system disk, 1TB data disk (plus 2x eSATA ports for external disks), DVD-RW, BluRay-RW, 896MB 275GTX graphics card, Vista 64 Business, Matrox RTX2 card, CS4 Production Suite