Limit with number of content items in WCM v5.x ?

As we currently experience crash of our portal production cluster, we have been in contact with IBM support. Of course, as we are still on v5.x, one of the first recommendation of the support was to migrate asap to v6.

But another feedback was that our crash issues (high cpu et frequent gc cycle) might also be due to some limit in the number of content items in WCM v5.x...
Indeed, our current total count of items is about 40.000, and some interlocutor at the support told us that some performances issues could be experienced with such a volume of data (either 40 or 50.000 items).
This was of course a very bad news for us, and a major risk for our portal...

On the other side, IBM tech sales expert told us that there is actually no pre-defined limit at the application level...however, as the WCM system stores a lot of data in memory (as caches, indexes, etc) the limit is the one of the hardware system: it is mainly the JVM memory that is the first bottleneck, but it could be also the CPU or the disk I/O...

So yes I think we can consider that there is a limit due to the design of the WCM application, even if this limit depends on the memory and hardware components.

The symptoms (if you think you might experience such problem) is supposed to be a slow degradation of system performances...So you will not see a sudden crash, but rather a chronic performance issue.

Another interesting information: IBM also told us that a few of their customers have been able to create and use WCM databases with more than 50.000 items (even 80.000 ?). So it is possible...

By the way, we still didn't found the cause of our portal crashes (but it is probably due to another problem than a system limit).
Another comment: since approx 2 month, our WCM authoring system is becoming more and more slow...IBM support is investigating and currently check if the problem is not related to WCM indexes....I hope we are not reaching the indexes limit :-)