Excessive CPU Memory from Intercheck ? Anything to stop this ?

I don't have the answer to your question, but I can say that for me, Intercheck (the On Access scanner) takes up ~80MB real mem and ~100MB of virtual mem (enabled or disabled).  It usually uses around 0.1% of my CPU and spawns 13 threads on a machine with similar setup to yours.

Do you have Preferences... -> On-access Scanning -> Options -> Scan: Inside archives and compressed files/Files on network volumes enabled?  If you're scanning archives on network volumes, this will definitely increase the amount of real and virtual memory requuired.

Thanks for the reply "Agile".

FYI, I have "Inside archives and compressed files/Files on network volumes" disabled.

Any solution for getting rid Intercheck (the On Access scanner) ?

You can quit it from the activity monitor app; it will re-launch, but should not be such a memory hog the second time around.

Do you have anything else running that does a lot of reads/writes to/from disk?  There's another thread on here about an app that just doesn't play well with Intercheck (can't recall the thread right now).

I tried force quitting "Intercheck" and it re-launched with the same memory hog.

I have nothing else that does a lot of intensive reads/writes to/from disk.

i have the same problem on a late 2010 MB Air. the fans never kick in unless i'm using a windows 7 VM or after booting with intercheck. i think the answer is for sophos to fix it before people bin it. the same happened to symantec with norton 360. what a poor performer that was i expect better from sophos. bearing in mind we are using it to protect windows users not ourselves.

I'm having the same problem with InterCheck...insanely large memory requirement...hoping company will look into it.

Do you have any log files or error messages that are logged around the time of the large memory usage?

Standard test points are:

Does the problem exist with Live Protection disabled?

Does the problem exist with Archive Scanning disabled for the on-access scanner?

Does the problem exist all the time, or just when certain applications are open?  Are there lots of file changes going on/large files being modified?

--Does excluding the folder containing large archive or media files being constantly accessed fix the problem?

As a benchmark, Intercheck should normally be using 0% CPU and (currently) take up around 107MB real memory when on-access scanning is disabled.  When enabled, it can quickly spike fo 12-25% CPU (2GHz benchmark) and then decline, and memory can grow based on the files being scanned.  For most casual use, I'm seeing the memory footprint move around between 113MB and 134MB.

I am having the same problem.  I am using Mountain Lion.  Turning off live protection improves things considerably.  What do you need to sort out what is going on? No error messages.

Are there any error messages in your system log (in console.app)? 

If the issue surrounds live protection, the problem is probably with your DNS lookups either failing or being severely delayed. 

This can happen for a number of reasons, from local DNS caching being misconfigured, to using a router/firewall that doesn't properly implement the DNS spec (taking shortcuts that fail when a Live Protection DNS request is made, as they're not standard domain lookups, even though they're properly formed, compliant DNS requests).

You could also try changing your DNS server (alternate ISP server, Google DNS, OpenDNS, etc.) to see if that improves the response times.

I only started encountering this problem when I installed java on my 2010 Mac. Same thing happened with Norton Security, and I was hugely disappointed. For whatever reason, Sophos seems to recognize java as a threat, and has caused it to error multiple times. For the time being, I'm removing Sophos from my system. Hopefully a fix is found sometime in the future!