When you run IOmeter and select a disk, that disk on the array is one device (at least if this is a Block configurations - the LUN which is in a Pool) and the IOPS (187.82) is what the LUN can handle, not the individual physical disks under the LUN that make up the Pool. For FILE it's a bit different as File takes a LUN(s) and creates a file system on the array and then presents that to a host as a device (I think this is correct - I'm not a File person). That File system may behave differently than a LUN on the Block side.
If you have 8 physical disks in the Pool using Raid 6, then you have a 6+2 configuration. Each individual disk can handle about 80 IOPS. So the total Pool can handle about 8 (disks) * 80 IOPS = 640 IOPS for the Pool. The 80 IOPS is based on a small block (less than 32KB IO Size), random IO (combination of Reads and Writes 70/30) workload. If you increase the IO Size, then IOPS will be less, but Bandwidth increases. Check page 115 in the "EMC Unified Storage Best Practices for Performance and Availability - Common Platform and Block Storage 31.5 — Applied Best Practices.pd" document that I attached in my last post.