total data is 60000 and batch size is 100 so to complete one epoch the no. of iteration will be 60000/100 = 600 …so if the batch size is 1 like the previous case then the no. of iteration will be 60000 … so it will take a lot of time …by the way i am confused what you want to ask? you want your batch size to be 1 from earlier post and i think the above code is working fine for batch 1 but as above code has 3607 data so the no. of iteration is 3607 for for MNIST data it takes around 12 sec (600 iteration) then for 3607 iteration it will take around 6 times more about 72 sec… i think i am confused what you want to ask please be a little specific so that i can help…
ps. the speed also depends on other factor such as size of network and other preprocessing steps…so the above calculation is just a rough estimation