When you change the GPU/VPU mhz or their memory bandwidth you are changing how they were design to work. By doing so your answer would be meaningless because they weren't desgin to work that way. What you want is not real comparsion but Paper Specs. But every know its' all about REAL test, REAL RESULTs.
I'll give a example: American Boxing vs Tai boxing. If they fight by their own style,, most likey TAI would win. But if don't allow knee, kick, elbow, etc,,, to make it same as normal Boxing then of course American Boxing would mostly likey win., but how about what they have beening Eating, or the girls they sleep with, or the Death of their FAmily, ETc, etc.. ALL of them have to be the same by your meaning,, it's imposiable to compare.
Just like for chips, .13 Micron vs .15 micron, should we inlarge or decease the size on both, and the millions of Transitors on the chip, should we remove or add some on the other chip to make them both even? How about power should we only give the same power to run the chips? what about the cooling solution, both have to use the excat same heatsink and fan running at the same speed. Both Chip have to be the excat same size made but excat same people. in the Exact area,. ETC, ETC
Once agian, What you are asking is really stupid because the answer would mean nothing if you can't get everything excatly the same. If it's ok for .13 vs .15 micron why can't it be ok for 325 vs 500mhz. If it's ok to have ddr2 vs ddr1, why can't they have 128 vs 256 bit.
ARe you getting what I'm saying..... pork chop is different from Steak.