Too fully take advantage of optiminer's improvements you need a modern cpu that supports aes and avx2. For me on a E3-1240 i managed to double the hashrate with it. ( using 4 cores , on ubuntu 14.04 )
In your case using 2 cores yields more hash, the higher the combined hashrate the better. ( i assume you have an old dual core cpu )
What hashrate do you get with your E3-1240 on linux and how do you make a benchmark? I use the same CPU with Win10 and when the miner is running it shows between 400H/s-500H/s in each "accepted" line. No feeling if this is good or bad rate for my CPU.

I get about 240 H/s with -t6 on the E3-1240L.
What cpu (exact modelnr.) are you on ?
Were you running linux native or as a VM on top of windows10
If it was as a VM using what virtualization technology ?
if you ran it as a VM did /proc/cpuinfo show the aes , avx and avx2 flags ?
I don't use linux. Only Win10 is running on my machine. Windows system information says: "Xeon E3-1240 v5 3,5Ghz". The miner is startet with 8 threads.