I know it may have been asked before but I was wondering, what would be the best version to use for older pcs still on XP SP-3 and w/ Pentium 4, would 5.x or 6.x perform better. I am aware both have their strengths and weaknesses but which would be better using latest Full CIS 5.x or latest Full CIS 6.x, or should I just use the Comodo firewall and Avast.
Thought about installing and testing but someone might have done that already and might save me some time 
I have run both v5.0 and v6.0 on WinXP SP3 32 Bit with 1GB memory and they both run fine. I saw no difference between the two as far as performance. They differ in features, but you would be protected using either of them.
Thanks for the fast response. I was just wondering if there was a performance difference, maybe after they release an update or 2 for CIS 6.x, maybe there will be a difference. I’ll just stick with the 5.x for now then 8)
For the upcoming release of v6 expect a maintenance update dealing with bug fixing.
I don’t think there is much of a difference performance wise between v5 and v6 with the AV.
Currently using v6 on an Intel Atom netbook with 2 GB RAM on Win 8 which also has a double boot with XP. That’s where my observations come from. Win 8 and XP are pretty close with regard to performance.
Technically speaking v6 AV has the advantage of a cache for the AV to help improving performance by discarding of checked files which scan results are cached. On older systems however the cache builder can be taxing for the 5-10 minutes it runs.