Hi Samuel, Capture is a much easier tool to use and maintain then concept. However one advantage that Concept has is the constraint manager. If you are adding the rules at the schematic level then this function will not be available in Capture. In answer to your second question I have found that the best way to organise the rules for the DDR2 memory is to fix a length for the clocks and then set your propagation delays based on this length. For the data buses I have been using a set of Relative propagation delays to get the desired length matching. Overall the autorouter has done a good job with the propagation delay rules but sometimes if the area is tight it has trouble with the relative propagation delay rules. Personally I try to keep the relative propagation delay rules to a minimum. Rgrds Peter Hughes, PCB Designer, Concurrent Technologies, 4 Gilberd Close, Newcomen Way, Colchester, Essex, CO4 4WN. Tel: +44 1206 752626 Fax: +44 1206 751116 -----Original Message----- From: icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Samuel Cais Sent: 21 June 2006 16:41 To: icu-pcb-forum@xxxxxxxxxxxxx Subject: [PCB_FORUM] capture vs concept /autorouting ddr2 with allegro possible? Hello group, We are using project manager,concept 15.51-s010 and allegro 15.51 s035. We'll perhaps change concept for capture (orcad). I don't know capture so i would like to know basicaly what are the advantages of each tool. My 2nd question is for the ddr2.We are spending a lot of time adapting the length and I was wondering if the cadence autorouter is abable to route and adapt in length traces and if it is doing decent job? Thank you Samuel