[LAU] Focusrite 18i20 vs Behringer FCA1616/UMC1820 - Was: PreSonus 1818VSL vs Focusrite 18i20

[Olli]

Hi Ralf,

On 04.12.16 16:28, Olli wrote:
> > 2. Do I understand correctly, 64 samples cause more latency than 128
> >    samples?
> 
> Looks like it. But I will also run jack_iodelay next weekend to to
> measure some more settings and verify the results.

I ran some more tests with jack_iodelay:

# Scarlett 18i20
Both connected input and output channels are on the same device.

## 48 kHz, 256 frames, 2 periods
total roundtrip latency: 1299,813 frames (27,079ms)
extra loopback latency: 531 frames

## 48 kHz, 256 frames, 3 periods
total roundtrip latency: 1796,813 frames (37,434ms)
extra loopback latency: 772 frames

## 48 kHz, 128 frames, 2 periods
total roundtrip latency: 705,813 frames (14,704ms)
extra loopback latency: 321 frames

## 48 kHz, 128 frames, 3 periods
total roundtrip latency: 834,813 frames (17,392ms)
extra loopback latency: 322 frames


# Scarlett 18i20 + OctoPre
Connected input and output channels are on different devices.

## 48 kHz, 256 frames, 2 periods
total roundtrip latency: 1349,806 frames (28,121ms)
extra loopback latency: 581 frames

## 48 kHz, 256 frames, 3 periods
total roundtrip latency: 1801,806 frames (37,538ms)
extra loopback latency: 777 frames

## 48 kHz, 128 frames, 2 periods
total roundtrip latency: 713,806 frames (14,871ms)
extra loopback latency: 329 frames

## 48 kHz, 128 frames, 3 periods
total roundtrip latency: 990,806 frames (26,642ms)
extra loopback latency: 478 frames

I did not test any higher framerates (e. g. 96 kHz) since my Laptop does
not run very stable at them.

Regards,
Olli