I am editing on FCP 6 when i render all clips it shows " out of memory"

but with individual clips it has no problem

so how can solve this problem ?
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My file file information is here

2k [2048x856 square pix, 24 fps

sequence duration is 1:16:13:03

sequence setting is as footage properties

with cineform Neo 4 k

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system information

mac

xeon doudble dualcare 3.2 GhZ
8 GB RAM

2 SATA hardisk of 1gb each
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