I heard apple m4 ultra using 256gb HBM for studio and pro, but I don’t buy it. The 256GB maybe. But a HBM memory control that would go unused on laptops doesn’t

I heard apple m4 ultra using 256gb HBM for studio and pro, but I don’t buy it. The 256GB maybe. But a HBM memory control that would go unused on laptops doesn’t pass the smell test.