Topic: Feature Request: Native DirectMusic support for RME Midi drivers
I am using Ableton Live 7 which features DirectMusic (DM) support. As far as I am aware Cubase also offers DM support and I wouldn't wonder if Sonar does so, too. Unfortunately out of my 6 Midi interfaces (2 x PCI, 1 x FW, 3 x USB) only the PCI ones (MPU-401, Audiophile 24/96) come with native DM drivers. Some time ago I was told by Daniel Fuchs that with Cubase [Emulated] DirectMusic drivers perform best with the RME products, which strikes me odd.
[Emulated] DM is nothing but a software wrapper that translates to MME as far as I know. It's the least best option and on XP it adds an average of 5ms latency to all of my 7 Midi interfaces. RME's MME drivers are very good (with negible latencies and jitter), but the native DirectMusic drivers of my MPU-401 and Audiophile 24/96 offer even 0 (zero, null, nil, nada) Jitter while showing the same good latencies as the FF. I attribute that to the advanced timestamping methods used by DM compared to MME. Microsoft even released a patch (now included into SP1) for Vista that ensures the use of the High Precision Counter (HPC) with DM on Vista.
Here is a comparison of the FF400's performance with both MME and [Emulated] DM. As you can see using [Emulated] DM is absolutely no option compared to MME (high latency on XP, high jitter on Vista).
Fireface 400 - Firewire - MME - XP
Message latency: 0.37 ms Total time: 61.097 sec
Message jitter: 0.30 ms
Message max deviation: 0.70 ms
Fireface 400 - Firewire - MME - Vista
Message latency: 0.14 ms Total time: 61.174 sec
Message jitter: 0.30 ms
Message max deviation: 1.76 ms
Fireface 400 - Firewire - [Emulated] - XP
Message latency: 5.63 ms Total time: 3318.386 sec
Message jitter: 0.30 ms
Message max deviation: 2.84 ms
Fireface 400 - Firewire - [Emulated] - Vista
Message latency: 1.24 ms Total time: 1277.564 sec
Message jitter: 2.00 ms
Message max deviation: 6.26 ms
Here are the results of my PCI based Midi interfaces. They perform only slightly better (a testify of how good RME's drivers are), but when you consider that at 120 bpm a 1/16th note has a duration of only 2 ms then 0 ms jitter is still preferable to 0.3 ms (which corresponds to as much as 15% of the 1/16 notes duration) and the faster the bpm the worse that correlation gets. <---- forget that argument, its false, based on false math! ed:
Audiophile 24/96 - PCI- MME - XP
Message latency: 0.07 ms Total time: 61.085 sec
Message jitter: 0.08 ms
Message max deviation: 0.28 ms
Audiophile 24/96 - PCI - DirectMusic - XP
Message latency: 0.33 ms Total time: 1828.135 sec
Message jitter: 0.00 ms
Message max deviation: 0.10 ms
Audiophile 24/96 - PCI - DirectMusic - Vista
Message latency: 3.75 ms Total time: 5960.018 sec
Message jitter: 0.10 ms
Message max deviation: 1.23 ms
Onboard MPU-401 - PCI - MME
Message latency: 0.08 ms Total time: 61.095 sec
Message jitter: 0.09 ms
Message max deviation: 0.53 ms
Onboard MPU-401 - PCI - DirectMusic
Message latency: 0.37 ms Total time: 3056.020 sec
Message jitter: 0.01 ms
Message max deviation: 0.49 ms
Onboard MPU-401 - PCI - DirectMusic - Vista
Vista does not support MPU-401 devices anymore, but there is a Beta driver for Asus mainboards that offers DirectMusic support for Vista 32 (no MME, no 64-bit).
Message latency: 0.37 ms Total time: 5720.239 sec
Message jitter: 0.01 ms
Message max deviation: 0.07 ms
Onboard MPU-401 - PCI - [Emulated] - XP
Message latency: 5.63 ms Total time: 3318.386 sec
Message jitter: 0.30 ms
Message max deviation: 2.84 ms