n     mmapv1   wt        wt        wt
                    rec str   rec str   lsm
                    snappy    no comp   snappy

 10000     48076    39062     39215     38314
 20000     52083    40816     39370     37735
 30000     50505    39062     39682     38461
 40000     52356    40322     38910     37878
 50000     52356    36630     37174     35971
   ...
400000     37313    37313     37174     32258
410000     38022    40485     38610     33112
420000     37037    42016     40650     35335
430000     35971    39370     39370     31347
440000     37037    38314     39525     34013
450000     38461    38314     38167     33670
460000     37593    19920     20449      3943
470000     38022     5396      6020       592
480000     38610     2217      1959       275
490000     38167     1140      1150       229
500000     37313      832       829       169

function create(size) {
    db.createCollection("c", {capped: true, size: size})
}
    
function insert(count) {
    var every = 10000
    var bulk = db.c.initializeUnorderedBulkOp();
    var t = new Date()
    for (var i=0; i<=count; i++) {
        if (i>0 && i%every==0) {
            bulk.execute();
            bulk = db.c.initializeUnorderedBulkOp();
            tt = new Date()
            print(i, Math.floor(every / (tt-t) * 1000))
            t = tt
        }
        bulk.insert({})
    }
}

create(10000000)
insert(500000)