Sound Startup Latency Tests
E-Prime reports millisecond accurate timing. This does not mean that E-Prime is capable of making hardware do things it cannot. For experiment paradigms that require auditory stimuli, much care and concern should be considered with the hardware being used. Sound cards can have good or poor startup latency, which is the time from when E-Prime tells the sound card to play sound to when the sound actually emits from the sound card or speakers. Not all sound cards are created equal. Results can also depend on the selected sound card driver and selected API (application programming interface). The default API used by Windows XP and E-Prime 1.0, E-Prime 1.1, E-Prime 1.2, and E-Prime 2.0 is DirectSound, which is the capabilities offered by DirectX. E-Prime 2.0.10.X allows for the option of selecting the DirectSound, ASIO or CoreAudio/WASAPI APIs so that the API with the lowest possible sound latency for a particular sound card may be used.
For more information on APIs in Windows Vista and 7, please see this article: INFO: Sound Latency - Windows Vista / Windows 7 (and beyond). To determine the best API for your hardware, please see the chart below or use our Sound Tester program as detailed in this article: INFO: Use of SoundTester to determine machine compatibility with ASIO or CoreAudio/WASAP API. Also, note that if the DirectSound sound startup latencies reported below are acceptable for a specific paradigm, the E-Prime experiment's Sound device will not need to be configured or changed and the defaults may be used.
PST encourages using external equipment to determine the startup latency of your sound card. For our tests, we collected data using a Black Box Toolkit (BBTK) connected to a HP ZD7000 laptop. For more information on the BBTK, please visit their website at http://www.blackboxtoolkit.com/. Each experiment computer generated a sound as well as a parallel port pulse that was detected by the BBTK's microphone and line in respectively. All sounds were sent through the same Altec Lansing VS2620 speakers. There were a total of 18 sounds and port pulses collected for each session. The experiment paradigm used white noise files that were set to 2 channels, 16 bit, and 44.1Khz. The parallel port pulse was sent at the start of the SoundOut object in the experiment paradigm. Since parallel port pulses have been shown to have extremely low latency, the receipt of this pulse represented the time that the sound was sent from E-Prime to Windows for processing. This was compared to the time that the BBTK received the sound through the experiment computer's speakers. The difference in these two times represented the sound startup latency, that is, the amount of time that Windows, the sound card, and the speakers processed the sound before it was audible.
As a result of our tests for Windows 7, PST generally recommends on board sound with the default High Definition Audio Device driver and the CoreAudio API. In Windows Vista, we recommend an add-on PCI or PCIe sound card with the manufacturer's driver and the CoreAudio API. For Windows XP, on board sound was found to be comparable to some add-on cards.
New E-Prime 2.0 Sound Card Startup Latency Results
| Adapter | Type | Machine | Operating System | Driver | API/Expected Latency | Mean (ms) | StdDev | Min (ms) | Max (ms) | On Board | n/a | Ad Hoc Quad Core | 7x64 | HDAudio | DirectSound | 40.733 | 4.217 | 34.000 | 49.000 | On Board | n/a | Ad Hoc Quad Core | 7x64 | HDAudio | CoreAudio 3ms | 5.533 | 1.060 | 4.000 | 7.000 | On Board | n/a | Ad Hoc Quad Core | 7x64 | HDAudio | ASIO4ALL 4ms | 6.071 | 0.616 | 5.000 | 7.000 | Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | 7x64 | HDAudio | DirectSound | 55.000 | 5.306 | 50.000 | 71.000 | Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | 7x64 | HDAudio | CoreAudio 3ms | 3.643 | 1.008 | 2.000 | 5.000 | Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | 7x64 | manufacturer | DirectSound | 344.267 | 830.216 | 119.000 | 3345.000 | Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | 7x64 | manufacturer | CoreAudio 3ms | 28.214 | 3.017 | 23.000 | 32.000 | Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | 7x64 | manufacturer | ASIO4ALL 4ms | 16.714 | 0.611 | 16.000 | 18.000 | Sound Blaster SB0790 X-Fi | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | DirectSound | 142.200 | 12.359 | 134.000 | 186.000 | Sound Blaster SB0790 X-Fi | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | CoreAudio 3ms | 18.600 | 3.043 | 15.000 | 23.000 | Sound Blaster SB0790 X-Fi | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | ASIO4ALL 4ms | 357.143 | 0.864 | 356.000 | 359.000 | Asus Xonar DG | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | DirectSound | 69.643 | 1.277 | 68.000 | 72.000 | Asus Xonar DG | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | CoreAudio 3ms | 26.400 | 2.063 | 23.000 | 29.000 | Asus Xonar DG | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | ASIO4ALL 4ms | 367.786 | 0.802 | 366.000 | 369.000 | HT Omega Striker 7.1 | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | DirectSound | 88.071 | 3.025 | 83.000 | 93.000 | HT Omega Striker 7.1 | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | CoreAudio 3ms | 25.071 | 1.685 | 23.000 | 28.000 | HT Omega Striker 7.1 | PCI | Ad Hoc Quad Core | 7x64 | manufacturer | ASIO4ALL 4ms | 366.714 | 0.914 | 365.000 | 368.000 | On Board | n/a | Dell Precision T3400 | 7x64 | HDAudio | DirectSound | 44.714 | 8.416 | 35.000 | 70.000 | On Board | n/a | Dell Precision T3400 | 7x64 | HDAudio | CoreAudio 3ms | 8.214 | 1.122 | 7.000 | 10.000 | On Board | n/a | Dell Precision T3400 | 7x64 | HDAudio | ASIO4ALL 4ms | 6.643 | 0.929 | 5.000 | 8.000 | On Board | n/a | HP Pavilion dv7t-1000 laptop | 7x64 | HDAudio | DirectSound | 47.357 | 3.795 | 43.000 | 53.000 | On Board | n/a | HP Pavilion dv7t-1000 laptop | 7x64 | HDAudio | CoreAudio 3ms | 6.214 | 1.051 | 5.000 | 8.000 | On Board | n/a | HP Pavilion dv7t-1000 laptop | 7x64 | HDAudio | ASIO4ALL 4ms | 6.267 | 0.458 | 6.000 | 7.000 |
|---|
| Adapter | Type | Machine | Operating System | Driver | API/Expected Latency | Mean (ms) | StdDev | Min (ms) | Max (ms) |
|---|---|---|---|---|---|---|---|---|---|
| On Board | n/a | Ad Hoc Quad Core | Vista x86 | HDAudio | DirectSound | 58.400 | 7.278 | 53.000 | 83.000 |
| On Board | n/a | Ad Hoc Quad Core | Vista x86 | HDAudio | CoreAudio | unusable | |||
| On Board | n/a | Ad Hoc Quad Core | Vista x86 | HDAudio | ASIO4ALL 4ms | 19.786 | 2.806 | 15.000 | 24.000 |
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | Vista x86 | HDAudio | DirectSound | 58.933 | 5.535 | 53.000 | 76.000 |
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | Vista x86 | HDAudio | CoreAudio 90ms | 136.357 | 29.705 | 92.000 | 177.000 |
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | Vista x86 | HDAudio | ASIO4ALL 4ms | unusable | |||
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | Vista x86 | manufacturer | DirectSound | 129.667 | 24.307 | 120.000 | 217.000 |
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | Vista x86 | manufacturer | CoreAudio 3ms | 26.800 | 3.509 | 22.000 | 32.000 |
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | Vista x86 | manufacturer | ASIO4ALL 4ms | 17.286 | 0.611 | 16.000 | 18.000 |
| Asus Xonar DG | PCI | Ad Hoc Quad Core | Vista x86 | manufacturer | DirectSound | 69.200 | 1.146 | 68.000 | 72.000 |
| Asus Xonar DG | PCI | Ad Hoc Quad Core | Vista x86 | manufacturer | CoreAudio 3ms | 26.867 | 1.685 | 24.000 | 30.000 |
| Asus Xonar DG | PCI | Ad Hoc Quad Core | Vista x86 | manufacturer | ASIO4ALL 4ms | 367.000 | 0.756 | 366.000 | 368.000 |
| Adapter | Type | Machine | Operating System | Driver | API/Expected Latency | Mean (ms) | StdDev | Min (ms) | Max (ms) |
|---|---|---|---|---|---|---|---|---|---|
| On Board | n/a | Ad Hoc Quad Core | XP x86 | default | DirectSound | 29.400 | 0.986 | 27.000 | 31.000 |
| Sound Blaster SB0880 X-Fi | PCIe | Ad Hoc Quad Core | XP x86 | manufacturer | DirectSound | 11.667 | 0.488 | 11.000 | 12.000 |
| Asus Xonar DG | PCI | Ad Hoc Quad Core | XP x86 | manufacturer | DirectSound | 69.133 | 1.642 | 67.000 | 72.000 |
E-Prime Legacy (Version 1.2) Sound Card Startup Latency Results
|
Adapter |
Type |
Machine |
Operating System |
Mean (ms) |
StdDev |
Min (ms) |
Max (ms) |
|---|---|---|---|---|---|---|---|
|
Sound Blaster 128 |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
6.708 |
2.116 |
1.000 |
9.000 |
|
Sound Blaster Live! |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
2.042 |
0.204 |
2.000 |
3.000 |
|
Sound Blaster Audigy 2 |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
2.500 |
0.590 |
2.000 |
4.000 |
|
Sound Blaster Live! 24 External |
USB |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
10.208 |
2.146 |
7.000 |
14.000 |
|
Turtle Beach Santa Cruz |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
3.083 |
0.408 |
3.000 |
5.000 |
|
Avance Logic AW200 |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
7.667 |
1.274 |
6.000 |
12.000 |
|
Yamaha Xwave A571-T20 ESS Allegro |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
12.792 |
3.189 |
7.000 |
16.000 |
|
Sound Blaster Ensoniq |
PCI |
Dell 8200 Desktop (2.2 GHZ) |
Windows XP SP2 |
4.875 |
3.803 |
1.000 |
16.000 |
|
Sound Blaster Audigy2 PCMCIA |
PCMCIA (Laptop) |
HP ZD7000 2.8GHZ |
Windows XP SP2 |
3.333 |
0.482 |
3.000 |
4.000 |
|
Conexant AMC Audio |
Motherboard Chipset |
HP ZD7000 2.8GHZ |
Windows XP SP2 |
18.000 |
0.000 |
18.000 |
18.000 |
Paradigm
The paradigm used on the E-Prime side was the SoundExperimentStation.es file. The sound devices were set at 2 channels, 16 bit, 44.1Khz. A white noise sound file was used. Event generation file used on the BBTK The results are from 24 trials per subject/session.
Equipment
- E-Prime 1.2.1.841 was used.
- The E-Prime desktop computer was a Dell 8200 Desktop (2.2 GHZ).
- 2.2 GHZ machine running Windows XP SP2.
- The E-Prime laptop computer was an HP ZD7000.
- 2.8 GHZ machine running Windows XP SP2.
- The BBTK computer was an HP ZD7000.
- 3.0 GHZ machine running Windows XP SP2.
- Hyperthreading was turned on all computers.
- The MSCONFIG diagnostic mode was used to shut down background applications and services.
