Comment by kimixa

The 256GB Mac Studio (the one with "eight times the RAM") is listed for ~$2000 more than the current 5090 prices, and another additional $1500 for the 80-core GPU variant. Only the "base" model with 96gb is a remotely similar price, $3600-$4000.

And a 5090 has a little over 2x the memory bandwidth - ~820GB/s vs ~1790GB/s. And significantly higher peak FLOPS on the 5090 too.

Sure, if the goal is to get the "Cheapest single-device system with 256GB ram" it looks pretty good, but there's lots of other axes it falls down on. Great if you know you don't care about them, but not "Better In Every Way". Arguably, better in only a single way - but that single way may well be the one you need.

And the current 5090 price might be a transient peak - only three months ago they were closer to $2500 - significantly less than half the $6000 base-spec 256GB Mac Studio. While the Mac Studio has been constant.