Benchmarking for Storage devices

[Tamesh16]

So i have been using HD tune for a while as my bench marking tool and even though i am not sure how the block size affects the bench marking, based on the basic size of a sector which is a block i use 64 Kbs , ( of which i assume is the same as test size in crystal disk mark ) any ways if you could help me understand that , it would be great , in any case 

Hd tune gives the rough values of transfer to the system bus but recently i have gotten a ssd and i use Samsung magician and i also have been using Crystal disk mark but these two seem to benchmark the actual disk meaning the transfer rates of the actual drive. 

so quite confused by this , i get how Hd tune works, but magician and crystal disk are tad bit more confusing , do they use the drive controllers to benchmark?

Another thing is representation of data 

so Transfer rates on Hd tune i assume is read speeds and access times as latency but ssds based on julia's episode have latency of 2 ms and well my benchmark says 0.1 ms so not sure whats wrong there and in hd tune burst rate seems to be as it says the read speeds if the drive is accessed quite suddenly but in hd tune it detects it as being only 20mbs faster than a 850 evo, which seems strange as well.

 

in Crystal disk  mark  there is different types of sequential benchmarking which i am not sure what they mean, usually any benchmark for drives on this forum use crystal disk, but i have no idea how to use it, the first set of results seem to match the ones i get from magician so i just use those values when  i am comparing drives with crystal disk mark 

 

one last thing is when i use magician to benchmark a hdd it just gives terrible results, and i know it shouldnt be used for a hdd, i assume its coded for ssds , but i would think if hd tune can do both then the principle should be the same or i am not doing benchmarking right.

so in conclusion

what does block/test size do and how does it affect hdds and ssd?

differences betweens hd tune and crystal disk mark and which is better ?