Radeon 9500: What About the Differences?

Apparently, there will be two versions of RADEON 9500 powered graphics cards, following the latest traditions of ATI Technologies: RADEON 9500 and RADEON 9500 PRO. The price of the more powerful one will be $219, while the cost of the former will be about $179. Both solutions will be equipped with 64MB of DDR SDRAM and utilise 128-bit memory bus. In fact, I still have no idea about the clock-speed difference between these two devices, I now even doubt that they actually will.

If the RADEON 9500 as well as the RADEON 9500 PRO are only equipped with 64MB of onboard memory, there is quite high possibility that there will not be used expensive BGA chips, but rather cheap and widely-spread TSOP chips. The latter fact also corresponds to the information about 128-bit bus. Since I have not yet seen TSOP memory that was able to work at frequencies above 275 (550)MHz, I have to conclude that both novelties will have the same memory speed of 550MHz.
So, the difference between the RADEON 9500 and 9500 PRO is not quite clear for me. I do not think ATI will lower the clock-speed of their already simplified version of the RADEON 9700, hence, either the RADEON 9500 PRO will run at 325MHz or will be clocked at the same 275MHz like its cheaper brother. I would like to point out that $40 is pretty significant difference in price, hence there should be some even more important differences between these two solutions that do not concern the frequencies.
Maybe ATI will reduce the number of rendering pipelines on the RADEON 9500, from the RADEON 9500 PRO, for instance, if the latter provides eight of them, the former will only offer us four. Since the RADEON 9500 is derivative from the RADEON 9700, it will support the DirectX 9.0 as well as AGP 8x transfer rate.