If you remember Geforce 8500GT was the first 55nm chip that Nvidia produced and this was the chip that started Nvidia's branding confusion.
It first launched as 65nm part and it was slowly replaced with 55nm chips. Now Nvidia has a better plan. It wants to rebrand the chip that we knew as Geforce 8500GT and simply sell it as Geforce 9400GS.
This is where the 128-bit memory interface comes from. There is only one problem for Nvidia, G96 the chip behind both 9400GS and 8500GT costs around $30, which makes it hard for Nvidia and its partners to make enough money off these cards.
The 9400GS will compete with RV730PRO, a modestly clocked entry-level chip, but we suspect that ATI might win this one. Remember, the sub-$60 market is very important as you can sell millions of these cards, and volume makes the revenue.