I have also seen the very long delays when sliding certain diff pairs also on large designs. I found the problem is caused by positive dynamic shapes in close proximity somewhere in the design to the diff pair signal. I believe the drc and healing function is slowing it down even when the slide is not close to the shape. I moved the positive dynamic shape off the board temporarily and everything is back to speed. We do very large designs on Dell Xeon 2 ghz 1 GB computers with dual nvidia monitors no problem. I also have a nice switch box that is controlled by the scroll lock button that swithes one monitor to another computer because the main computer does not have dual processors. I got it at Fry's for about $40 and it is made by Ingear. -----Original Message----- From: george.h.patrick@xxxxxxxxxxxxxx [mailto:george.h.patrick@xxxxxxxxxxxxxx] Sent: Thursday, May 19, 2005 4:44 PM To: icu-pcb-forum@xxxxxxxxxxxxx Subject: [PCB_FORUM] Re: System requirements for 15.2 I have a dual 2.66 GHz Xeons w/ 2 GB of memory. I still get lags on large boards with lots of planes. I am going to try 3 GB of memory (the most I can stick in it), but there was almost NO improvement from 1 GB to 2, so I don't think that's going to help :( There are some differential pairs that have a 20 second lag in them from the time I start sliding to the time they actually move. Sure would be nice if Cadence would multi-thread Allegro so it could actually USE both processors. It's going to get worse as Intel switches to multi-core processors instead of increasing bus speeds. -- George Patrick Tektronix, Inc. Central Engineering, PCB Design Group P.O. Box 500, M/S 39-512 Beaverton, OR 97077-0001 Phone: 503-627-5272 Fax: 503-627-5587 <http://www.tektronix.com/> http://www.tektronix.com <http://www.pcb-designer.com/> http://www.pcb-designer.com It's my opinion, not Tektronix' -----Original Message----- From: icu-pcb-forum-bounce@xxxxxxxxxxxxx [mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Sawyer Jayne Sent: Thursday, May 19, 2005 14:34 To: icu-pcb-forum@xxxxxxxxxxxxx Cc: Anderson Gary; Cech Charles Subject: [PCB_FORUM] System requirements for 15.2 Since moving to 15.2 and positive planes we have been experiencing considerable lag time when running DRC, using the electrical constraints for diff pairs or doing edits to the planes. The boards we are having issue with are 17" X 14" 16 layers 23477 connects 24000 via We are looking to upgrading our hardware. I am hoping that some one in the group might be working with similar conditions and already have updated to a machine that could handle it. If any one can help me to spec a capable machine please let me know. Thanks in advance, Jayne Sawyer