Perf L2 TSE here! First of all, perf issues can be a pain to track down sometimes. We are working on some KBs to try to simplify the process, but could use some feedback as well!
So, a few things:
1) What kind of filer, and what kind of disks (X # with fw version please too).
2) In AIQUM, in the volume, you can see the breakdown of cluster components in the latency graph. Where is the latency?
3) What protocol?
4) Have you ever had latency at 10 ms?
5) Is this workload normal or unusual in terms of load?
6) What is the expected latency? If not sure, will need to validate with AIQUM.
7) Version of ONTAP?
Now I can think of a few scenarios this could be:
1) Latency amplification because vSphere is reporting upstream of ONTAP. In this case, if you took a VROPs/vSphere latency graph at the datastore level compared to an AIQUM graph, they would have the same or similar graphs, but just higher peaks and valleys in VMware. In this case, I'm not surprised because it may be queuing at the network/host side a tad bit. Probably 10 ms is too high here.
2) A huge discrepancy due to network delay. If iSCSI/NFS, I just like to get a tcpdump from the filer during the issue. It's honestly the best way to troubleshoot network problems. Bonus points if you can get tcpdumps from ESX (you'll need to start two, one for ingress and one for egress and merge with Wireshark).
3) This latency has been this way all this time, but something changed in the amount of data the job has to process.
And to the question above about the max IOPs an aggregate can produce, we don't publish those guidelines because unlike Solidfire for example, ONTAP is designed for many different workloads and varying performance profiles from small to large block, and metadata from small to big needs. An op will have a different cost, and it is highly dependent on your individual workloads. Customers have different workloads even if they say they run a "standard" VMware install for example, so I've found there is no standardization.
If you want sizing numbers, please get with your account rep/SE to discuss sizing and what your limits are. Generally that is done before sale of a system, even for an upgrade/head swap.