Stripe size and perf. degredation due to lack of trim

So lack of trim is bad, but raid is good, that much we know. Say you're in an array and you don't have trim, would your stripe size have any effect on the rate of (or amount of) performance degradation you experience?

PS> Generally accepted stripe sizes are 64k and 128k, but I feel as though I have the option of going lower - to 16k or 32k - since I'm using an i7-930 *if* there is any benefit in doing so.