That sounds logical. The reason I am asking is I found the IOPS for CX700/500/300 which are 200K, 120K and 50K respectively. I could not find any such info for DMX-3, though, DMX and CX are very different in their architectures.

For small block IOs, 5,000 on a CPU is probably a good place to stop putting load on it.

Performing a read miss operation is more expensive for the FA CPU than a read hit. For the miss case, the FA must send a request for the data to the DA CPU. The result is the FA CPU can do 1/2 the maximum IO rate if it is 100% miss than if it is 100% hit.

So if you know your average workload profile (size, R/W ratio, and hit ratio) we could estimate what your maximum would be.

Makes sense. You are correct. Having some published guidelines based on IO profile mix for FA's will help a lot. This is a very common query by users. - Thanks.

Quazi, based on my experience if you running the FA processor over 5000-6000 IOPS (assuming small block size 4kb, 8kb) you should start watching the utilization on FA processor. Obviously this is my opinion only. There is a HW limit and there is a realistic limit (previous response: "it depends" based on IO profile)

Quincy, does the cache mechanics really matter for FA IOPS maximus, as it will only slow down the FA and not necessarily a direct FA limilation. The maximum will still be true.?

That sounds like the system limit, however in CLARiiON, all the CPU power can be applied to one port. In DMX, there are seperate CPUs for every front end director "slice".

Those also sound like the maximum IO rates for small reads (probably hits). I bet if you were doing 1MB IOs that the CLARiiON CX700 couldn't do 200,000 IOs/sec. That would be about 186GB/sec. :-D

I've seen 5k - 6k per cpu and I was not having real performance issues. However: in ECC I had counters that would trigger an alert when getting over 5k 3 times in a row, 6k 2 times ni a row and 7.5k when the cpu hit that number. I would dig in that cpu and start monitoring if there was something going on there. Normally IOps wouldn't get over 2-3k or so.

Wow! A lot of insight into the fact. Thanks a lot guys, I can't explain how much I appreciate your valuable inputs here.

Along with the other things mentioned in this thread, what is your sampling rate? If you are seeing 7,000 IOs/sec average over a 15-30 minute period, I would worry more than if you were looking over a 60 second or less interval.