sol = hash
H/s = hash per second
MH = Million hashes per second
Ether mining produces hash rates thousands of times faster than Zcash, so you use MH.
a solution is not the same as a hash.
They are fundamentally different measurement.
ZCash reads out in sol/s because the Devs believe it is a better measure than hashes.
That last sentence makes little sense and is misleading.
OP, it sounds like you were equating the hashrate your cards get ethereum mining to zcash mining. You should just test mining some zcash to see how fast your rig is.
At the moment, your AMD cards are almost certainly 15%+ more profitable mining eth than zcash, but that can change very quickly.
I knew someone was going to say that...
1) I know they are not the same BUT the pools, miner software, and calcs all interchange sol to hash at 1:1, so that is how we use it now.
2) Not really. if you have 28 mh on ETH and 300 h/s on Zcash then ETH is hashing 93'000 times faster. It is a different algo, so the speed difference is meaningless.