Extremely Slow Speed on SSD RAID5

I have a Dell R810 with a PERC H700. I was running 600GB 10K SAS Drives for the longest time. Very reliable, only had 1 fail in the past 3 years. I decided to upgrade the system to some HGST 800GB 12G SAS SSDs. Now these were some cheap drives off of ebay, so I don't know what I was expecting. I had to fix the sector size from 520 to 512 for the RAID card to even work with these drives, but now that it's working, I'm noticing the speed of this configuration is extremely slow. I did a comparison using a Windows VM on each system, HDD vs SSD. 6 Drives in a RAID 5. The HDD is faster than the SSDs about 6x. I don't know what I'm doing wrong here, but this can't be. Each drive should be capable of 1000MB/s each. I get that I lose speed to the parity, but something is wrong here.