Hashrate difference between T-rex and Ethermine

So I'm relatively new to mining, and saw raven on Etherimine, I like its protocall but the main draw for me mining it was ETH going to 2.0 so miners will be going somewhere else and those coins will most likely increase in price. however I am noticing a difference in hashrate between trex and ethermine is this common for Raven or is something I'm doing wrong?

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T-rex 28MH/s ish

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Etherimine 6.3 MH/s

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while doing ETH its pretty close to the same hashrate.