EVA 8400 Processor Speed

[Uwe Zessin]

Patrick,
a single "4 GB backend-loop" has a bandwidth of 400 MegaBytes per second, not 4,000.

[Patrick Terlisten]

Hello Uwe,

you're right, my fault. Maybe I should repeat some classes in primary school to refresh my knowledge in elementary mathematics. :-|

Best regards,
Patrick

[Torsten.]

I found a source that talks about the processor:

http://de.wikipedia.org/wiki/Enterprise_Virtual_Array

Sorry, I did not found something in english wiki.

It says, PowerPC CPUs are used, but I don't think this is relevant for overall array performance in any way.
BTW, some of them have even 128bit processing in certain units, AFAIK.

[Patrick Terlisten]

Hello Torsten,

I wrote the first version this wiki article nearly a year ago. I don't know if the PPC cpu is doing all the work, rather I think that the PPC is supported by some other special ASIC. There is another hint in the OCP menu under "System Information -> PIC -> PowerPC Processor".

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00365593

Best regards,
Patrick

[Torsten.]

Nice work.
I know for sure it is a PPC CPU :-) but it doesn't really matter.

[Uwe Zessin]

> some other

There are a number of special ASICs to do the work.

[Jeffrey Wolfanger]

Well the CPU on 8400s do often go above 20% in production I see them as high as 90 with a mean at 70% and that is far from fully loaded. So to the comments on to why it matters and 8400 isnt an 8000 and it does matter.

[DavidWarburton]

I'm having the same problem with our 8400 too.

We had some really weird issues where one controller would be happily hovering around the 30% CPU usage but the other would either be at 0% or shoot up to 90%+ (either quick spikes or sustained for about 10-20 seconds).

I moved a really heavily used LUN to the other controller and both controllers are now much more evenly matched - sadly both controllers are now steady between 70-90% !!!

All these LUNs were previously on an 8100 and although I don't have any stats to back up my thoughts, we didn't seem to be suffering from such bad performance!

Can anyone give me any tips as to what's causing such high CPU usage? I mean I can see what LUNs have high IO and high latency, but I wouldn't have thought that CPU usage should EVER get this high (at least not sustained).