After I purchased and installed the 747-400 Queen of the Skies, I kept having on-going OOM (Out of Memory) crashes, and my computer seemed to be struggling when trying to fly this aircraft. Following the crash, I lost my desktop image and the desktop reverted to a light blue; everything was restored when I did a re-boot. I followed the message strings on the forum and eventually resolved my problems, and I am putting forward my solutions to add to the knowledge base.My current system is shown below, but at that time I only had 1GB of DDR RAM. I followed the performance graph in Task Manager, whilst flying, and the PageFile usage was just below IGB and gradually increased, leading to an OOM crash, as described above.I increased my RAM to 2GB (I had terrible problems doing this since my dealer started with 2x1GB Samsung cards; in the interim he had an heart attack and quintuple by-pass (age 42) and meanwhile my computer was crashing; when he returned to work, he found one Samsung card to be faulty; he replaced them with Kingston cards and they are now working okay). The 2GB RAM made a substantial improvement in the smoothness of the 747 performance.I then tried a flight from KLAX to CYVR and CYVR to KLAX and kept having OOM crashes in southern Oregon. Then after a lot of sleuthing, I found I had a Crater Lake landclass file in a scenery folder which had a texture folder. I moved this landclass file to a landclass scenery folder which did not have a texture folder, and my OOM crashes were cured.Next trip I wanted to do was Frankfurt to Vancouver in a Lufthansa 747, and I ended up having OOM crashes near Frankfurt and over Iceland. More sleuthing identified landclass file issues again, I corrected these and the other night took off from Frankfurt at 10pm, using the FMC and a flight plan converted from FSNavigator, and next morning when I got up, successfully landed the 747 at Vancouver about 10 hours later! Page File usage rarely exceeded 0.98Gb and then only to about 1.1GBMy experiences in summary;1.The PMDG 747-400 needs in excess of 1GB RAM to operate smoothly2. Really check landclass files to ensure that they are not coupled with a texture folderHope this is of value to simmersNigelVancouverMy System:AMD Athlon 64 3500+Gigabyte GA K8NS ULTRA-939 mobo ATI Radeon X800XL video card AGP (Omega drivers)2GB Samsung PC3200DDR RAMVirtual memory:C: system managed sizeG: (separate drive to C) paging file size 3072

>I increased my RAM to 2GB (I had terrible problems doing this>since my dealer started with 2x1GB Samsung cards; in the>interim he had an heart attack and quintuple by-pass (age 42)There's no amount of memory gonna cope with that buffer overflow... :(BTW, how can he have had a quintuple bypass when there's only four blood vessels to the heart?Andy Scholes.

Hi AndyDon't fully understand your comment re-buffering, the extra RAM has made a huge difference to the performance of the 747I'm not a doctor, but I thought you could have up to 8 by-passes - I've had two friends who had seven bypasses!Since you're Jock in the Frock, you must be from the old sod - I left Dundee in 1957 at the tender age of 22 and emigrated to Vancouver - never looked back, this is a wonderful place to live and simfly!Nigel