There seem to be two threads about performance that have come up in this forum: Latency (you want very low latency for tracking via software monitoring, if you need to track through effects such as a guitar amp) and Disk/Track count (which you want very high for large projects). This is NOT a test for track count. I set out to do a latency comparison between Logic 7 and Cubase SX3. First of all, my testing methodology (curtesy of Dennis Gunn): 1) Rec-Enable a stereo track 2) Plug guitar into one of the stereo inputs (in my case, right) 3) Route output (in my case, right) into the other input (in my case, left) 4) Record transients (hitting pickup with piece of metal) 5) Open region in SE and count the sample distance between the right and left transients. This gives a pretty accurate reading of round trip latency. I am recording 24-bit, 44.1k files. I am using an RME HDSP 9632 card which feeds a SPDIF signal to Metric Halo Mobile I/O ULN2 which serves as AD/DA and Mic-Preamp for the signals. After each of the latency tests, I do a "reality check playback test" in which I run a demo song at that buffer setting, as a test to see if that buffer setting is realistic for recording/playing back a project. I chose demo songs because since they are included with the package, everyone can verify my results on their machines, and because the demos are usually optimized to run well. Test machine: PowerMac G5 2Ghz dual processor, 1GB RAM, OSX 10.3.5 I'll start with Logic 7. 1st Logic Test: Core Audio Buffer: 64 samples Samples of Latency: 480 samples CPU usage of single stereo 24/44.1 track armed w/guitar amp pro inserted: less than 5% 2nd Logic Test: Core Audio Buffer: 32 samples Samples of Latency: 376 samples CPU usage of single stereo 24/44.1 track armed w/guitar amp pro inserted: about 5% Reality Check Playback Test: For my reality test, I ran the Logic 7 Demo Song (12" Full Track version). This song consists of: 50 tracks 17 Audio Instruments 100+ effects This song runs at 50% at 128 samples, with one peak at 80%. At 64 sample buffer, this song ran at about 60% CPU with one peak at 90%. At 32 sample buffer, this song ran at about 70% CPU with one peak at about 100% (both meters full up) but there was no audio dropout at all. In other words, recording tracks at 64 samples with a song like this could work, but recording tracks at 32 samples with a song like this might not work. Now for Cubase SX3. Cubase does not allow for buffer settings below 64 samples. Buffer: 64 samples Samples of latency: 545 samples However: Cubase SX 3 has an "Expert" mode in its driver section so I ran more tests: Audio Priority to Very High: 545 samples Lower Latency Checked: 416 samples Multi-Processing Unchecked: 545 samples Lower Latency, MP off, Very High Audio Priority: 416 samples. CPU usage of single stereo 24/44.1 track track armed w/overdrive effect inserted at 64 sample, low latency checked: 15%. Reality Check Playback Test: I used one of the SX3 demos, Blofeld's Return, because it also ran at 50% CPU at a 128 sample buffer. The song consists of: 42 tracks 4 instruments 5 plug-ins With my buffers set at 64 samples, this song would simply not play. At 64 samples and low latency the song seemed to be playing at varispeed, way slow and with lots of crackles (and peaked the meter regularly). With low latency off and audio priority set to high, the song played back normally, but there were still a couple peaks that caused audio dropouts. Even setting the preload to 6 seconds (the maximum allowed) the song simply would not play back at all. At 128 samples, however, even with Low Latency checked, the song ran at 50% CPU. From these results, I'm not sure if 64 sample recording is feasible in anything but a very small project using Cubase SX3 on a Macintosh. I'm assuming that its PC ASIO results would be better, however. (REMEMBER: this is not a "track count" test. With the buffer at 512 samples, the CPU use for the Cubase SX demo song drops to 20% and playback is not an issue. This is ONLY a low latency test). Analysis: Cubase/Nuendo may be the track count king, but for low latency recording with effects, Logic Pro 7 gets the nod. Orren -- http://www.mertonfolio.com Author of: • Logic_6_Power • GarageBand Ignite http://www.courseptr.com/ptr_catalog.cfm?group=Music%20Technology