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Hi there everyone,
So the problem is, I am running Windows 7 ultimate on a core i7 920 machine with 6bg of ram. When I run After effects cs4 it only recognises 4 cpu cores instead of 8 (because of hyperthreading).

I know that after effects is capable of utilising hyperthreading because it recognises all 8 cores on the imacs at my university.

Does anybody know why this is? or how to fix it?

Cheers

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Nikon D300s / 50mm f1.8D / 18-200mm VR / 70-300mm VR / micro Nikkor 60mm 2.8 / Tokina 11-16mm f2.8 / sb25 / Phottix cleon II

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I'm not running 7 yet, and besides I 'only' have a quad core 9650, so I can't talk from actual experience, but I do seem to recall some versions of Windows 7 could only access a limited number of cores. The first thing I'd do is fire-up task manager and see if you can see four or eight graphs for CPU performance. Maybe your OS is only seeing four.

Hopefully someone else will know for sure, otherwise the Adobe forums can be quite good. If you find the answer elsewhere, do let us know here...

Isn't it do with the number of physical cores? As far as I'm aware octo-core processors haven't been released yet, the I7 creates two virtual processors within each core when Hyperthreading is enabled to give effectively "8". I could be wrong but thats how I understand it!

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Canon EOS 50D/EF-S 18-55mm IS/EF-S 55250mm IS/EF 50mm F1.8 II /Lowepro AW Slingshot 200/ Digital Ixus 860 IS

PC>Q6700/MSI P45 Zilent/6GB 800mhz DDR2/2x 4870 1GB/Samsung Spinpoint F1 500GB/Maxtor 200GB+80GB


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my os definately sees all 8 cores, so im pretty sure its an After effects problem but i cant find any solutions on the net

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Nikon D300s / 50mm f1.8D / 18-200mm VR / 70-300mm VR / micro Nikkor 60mm 2.8 / Tokina 11-16mm f2.8 / sb25 / Phottix cleon II

My Flickr

.
Not software I use, I'm afraid, but you might find this online help page relevant. Note that in the CPUs To Leave For Other Applications section they say

Set this value to a number other than 0 to prevent After Effects from using all of the CPUs (processor cores) in your computer system. For example, if you have a computer with 8 CPUs, setting this value to 2 leaves 6 CPUs for After Effects.

It may be that After Effects CS4 is ignoring those virtual cores because Windows identifies them as such and the imacs OS doesn't but I'm guessing wildly.

In any event earlier on the same page it states that

Optimum performance is achieved with computer systems with at least 2 GB of installed RAM per processor core.

So you actually might achieve better performance with your 6GB of RAM if you set the Memory & Multiprocessing preferences to limit the number of cores to three rather than the four you have or the eight you want. You should be able to see whether three or four cores is quicker by timing the same job.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

No, you have 8 threads, not 8 cores. Read this...
http://www.intel.com/products/processor ... ations.htm

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Canon EOS 50D/EF-S 18-55mm IS/EF-S 55250mm IS/EF 50mm F1.8 II /Lowepro AW Slingshot 200/ Digital Ixus 860 IS

PC>Q6700/MSI P45 Zilent/6GB 800mhz DDR2/2x 4870 1GB/Samsung Spinpoint F1 500GB/Maxtor 200GB+80GB


My Flickr

yea, i know they are technically threads but hyperthreading technology allows the computer to read them as if they were extra cores, thus why in dxdiag it says "8 cores"

_________________
Nikon D300s / 50mm f1.8D / 18-200mm VR / 70-300mm VR / micro Nikkor 60mm 2.8 / Tokina 11-16mm f2.8 / sb25 / Phottix cleon II

My Flickr