Slow browsing after upgrade to Mavericks and SAV for Mac version 9

actually it slows all sites I visit but if you'd like names MacUpdate.com, Softpedia.com, VirtualBox.org, DeviantArt.com are just a few.

btw, I don't know if it's true or not but I read somewhere in the forums that when block sites is enabled Sophos checks a database of sites on their servers. what I think is perhaps it's your sire slowing down.

In simply terms: Web Protection works by taking the URL requested in a browser, pausing the connection, then checking in with a list SophosLabs maintains (globally available servers that are very fast) to see if it's malicious or not.  If it is bad then it's blocked and the page you see is a blocked page, otherwise the request is given back to the browser to carry on its connection.  Obviously doing that is 'extra work' and there may be a slight delay.  It's when the delay is quite noticable that we can look into it.  The technology has to check with central servers as the list is always being updated and you wouldn't want it locally on your computer.

I've spoken to our development team and they will comment.  They may ask you to look at the page load speed via Safari's or Chrome's developers options so maybe you can start to look at that and see if you can spot something loading particularly slowly in one of the example site.   Example of Safari:

one thing I should have mentioned is, in Firefox for example, when I try to go to a site the tab will have "connecting..." for quite a long time as if it can't talk to you, before it checks the URL.

somethings I've noticed as well are, without Sophos enabled pages do load virtually instantly but if I run a trace route to the same site there are all sorts of delays. I know others have had the same issue but if the developers want me to check someething I'd be happy to.

One thing I can't understand is why, when I reinstalled Sophos yesterday, there was no noticible delays all day and evening up through early morning. But when I woke my iMac from sleep when I got up everything was slow again.

Some delay is inevitable.  Each web request requires an additional lookup to check the server isn't malicious (though there's some caching which ought to eliminate some of these).  The reputation check is sent at the same time the request is sent to the server, so in theory by the time the computer receives the server's response it has already received the result of the reputation check.  There's an additional delay which occurs because most content will be scanned by the AV scanner as each response is completed.  With web protection disabled, the browser will have access to data as it is downloaded, and in some cases can begin rendering before the full response has been received - so poor speed and high latency can both contribute to perceived delays. A fast and reliable network minimises web protection delays.

Every effort is made to ensure that the reputation check is fast and reliable, but it can still be delayed by network congestion or unreliability.  Since the user will experience a delay if either the request to the web server *or* the reputation check is delayed, network issues can have a disproportionate impact on browsing experience when web protection is enabled - especially on sites like amazon.com where each page can consist of over a hundred elements.

I have a 75Mbps fiber connection. One of the reasons I chose Sophos in the first place was because it was much faster than the alternatives. To be fair once a page finally loads it behaves normally. But when you are used to pages loading nearly instantly the same pages taking 10-30 seconds to load seems interminable.

I've spent a little time seeing what impact Web Protection has on my browsing.  I have a relatively slow connection, and while I don't have access to a Mac right now, the Sophos Windows endpoint sofware does pretty much exactly the same thing on both platforms (though in my experience the Mac version is a little faster).  I'm using the Chrome browser.

For me, browsing to amazon.com takes 5 seconds before any content appears, and another seven before the spinner stops.  Turning off all web protection sees that drop to two seconds and five.  Content scanning only is 3 seconds and five.

The content scanning result (no reputation checks) is as expected.  It is stopping the browser seeing any content until each element has been fully downloaded -  for the main HTML page that's about a second delay.

Since the reputation lookup result may reasonably be expected to be available before the content scan occurs, it is clear that for me at least there's some delay to the real-time lookup.  The lost two or three seconds on a site like amazon isn't too bad considering the hundreds of lookups and scans which are needed to keep me safe.  Having said that I think it could be improved, and so warrants some further investigation (and this time with a Mac!).

Investigation has identified a couple of issues which are believed to cause the slow web browsing behaviour you're seeing.  These issues are only marginally apparent when reputation lookups are really fast (which unfortunately they are for us), but are expected to balloon spectacularly for slow or unreliable connections.  The changes required are not trivial, but are important and we're hopeful these issues can be resolved soon.

That's understandable. To be honest I have no fear of "things" getting into my computer. In the many, many years I've been using them I have never had an infection of any sort. I still like Sophos and still have it installed. I just have the web protection turned off for the moment. When you get it all sorted out I'm sure I will turn it back on again. And of course, any program which does any kind of website checking, email checking etc. will slow things down a bit. I look forward to the next update.