We did initially use m1.xlarge, a few years ago when we first started with HBase. I no longer have the hard numbers available, but while I agree HBase is memory hungry, our m1.xlarge servers were constantly pegged for CPU. For a while we ran both types, and eventually phased out the m1.xlarges entirely.
We run pretty frequent compactions due to our read and write patterns, so of course if you do not need to compact as often you might get much better mileage out of the m1.xlarge.
We run pretty frequent compactions due to our read and write patterns, so of course if you do not need to compact as often you might get much better mileage out of the m1.xlarge.