The speed of your fusion drive really depends on the ratio of your SSD to hard drive size and the overall data size on the drives. I have created about 5 fusion drives now all for the purposes of testing and it is not RAID 0 as people assume but Apple's answer to LVM (if you know Linux) and that being said it blows away the competition in terms of performance. A 128 GB drive with the stock Mini (I assume entry level 500 GB) won't give you much of a performance boost which is why Apple's sales point sucks imo because that's all they are giving you and they are charging a lot. A 240 or 256 GB will give you a substantial performance increase from the 90 MB/s benchmark I got on the 2012 drive alone (far better than 2011 that I just sold) to 250-300 MB/s. If you add 500 GB 840 SSD, now you are talking full SSD speeds as the ratio is 1:1. I tested an install with about 200 GB in data, first on SSD alone and second on fusion and there was no difference. The better thing about fusion besides giving you a 1 TB...