External sound card experience

In case this is useful here is some experience of adding andexternal (USB) sound card and whether it "helps" FS9.1) This was done a Dual D945 machine where there were no PCIslots left to add an internal sound card (the best option). Thecomparison is with the same computer using the on-board soundcard.2) The sound card was bought to rip my record/tape collection and used with a laptop that can be moved the the hifi. What Ithough I would try was to see what happens to the machine thatis used for FS.OK : preamble. There are a number of issues using on-board sound with FS, themain problem is that the sound card uses CPU time and band widthon the main FSB to do the sound. This can result in micro-stuttersoccasionally. Most of these micro-stutters can be got rid of bysetting the sound card acceleration to "basic" within DXDIAG. Thesecond problem is that the sound quality is usually not very good,and certainly poor with basic acceleration.The best solution is to get a PCI sound card. As noted, I did not have any PCI slots left in my machine, and second I bought the card for another use - so thought I would try it.The biggest problem with a USB (external) sound card is the USB drivers and operations are performed by the CPU : so this can hitthe CPU available for the simulation. The advantage is that theDAC operations and processing are done on the sound card, and notthe CPU - so the level of acceleration does not effect CPU.So : if I add my external sound card to my FS machine, will it improve the micro-stutter and give me better sound without effectingthe simulation rate (ie main CPU based measure). OK, so I imaged my machine (so I can go back) then installed thenew sound card.1) No more micro-stutters - I managed to restrict these to takeoff where there are lots of sounds being played with the internalsound card, but now they are gone completely.2) The sound quality : Wow - much better3) Effect on frame rate, none that I could see. Notice that I amusing this on a Dual machine. FS9 has 2 main threads, one to loadthe scene, and one to do all the calculations such as integration. The calculation thread (flying work) is maxed out. The scene threadis restricted by my FSB speed, and so has CPU left for other things;like USB work. My guess is that using an external sound card maybe problematic if you have a single core machine.It was certainly worth adding the external sound card on thisparticular machine. Even adding sound effects (stereo-surround)does not impact on the frame rate on the dual processor. It alsohas the advantage that I can remove the sound card when I am rippingmy records and tapes, and then the on-board sound still works.Hope this helpsTom