Hi littlezilla & cow cow
anything much over 3-400 MB of
real memory seems excessive in my experience over 10.5/6 & safari 3/4/5.
I use not much flash, due click2flash, but otherwise is thoroughly stock.
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there's no 'use less memory' preference, and I would think 1GB+ to be rare, so chances are there's something different on your systems, or in the content you browse. I guess that non-64 bit intels & ppc's may show a higher figure due plugins being included in safari's usage rather than showing up in a separate process.
I'd test in a
new user account, just long enough to make sure the problem remains, and then start with all plugins removed & work from there. It can be long-winded, but no-one else will do it for you, since believe it or not, 1GB + is unusual.
Naturally, you may find it simpler to use another browser