Passthrough · Comparison

Relayed reports

Each box relayed mice and keyboards at several report rates, 15 s each, with every report numbered.

Mouse reports reaching the PC

Mouse	Stock	Medius	Result
1 kHz mouse	All, once, in order	All, once, in order	Equal
500 Hz mouse	All, once, in order	All, once, in order	Equal
250 Hz mouse	All, once, in order	All, once, in order	Equal
125 Hz mouse	All, once, in order	All, once, in order	Equal
Mouse in bursts of 7 reports	All, once, in order	All, once, in order	Equal
500 Hz mouse for 2 minutes	All, once, in order	All, once, in order	Equal

Keyboard reports reaching the PC

Keyboard	Stock	Medius	Result
1 kHz keyboard	All, once, in order	All, once, in order	Equal
125 Hz keyboard	All, once, in order	All, once, in order	Equal
Keyboard in bursts of 7 reports	All, once, in order	All, once, in order	Equal

Report bytes reaching the PC

Device	Stock	Medius	Result
1 kHz mouse	Unchanged	Unchanged	Equal
500 Hz mouse	Unchanged	Unchanged	Equal
250 Hz mouse	Unchanged	Unchanged	Equal
125 Hz mouse	Unchanged	Unchanged	Equal
Mouse in bursts of 7 reports	Unchanged	Unchanged	Equal
1 kHz keyboard	Unchanged	Unchanged	Equal
125 Hz keyboard	Unchanged	Unchanged	Equal
Keyboard in bursts of 7 reports	Unchanged	Unchanged	Equal

Report timing

The relay runs above, timed on the PC's USB bus.

Reports >10% early or late, in 15 s

Mouse	Stock	Result
1 kHz mouse	0	Equal
500 Hz mouse	2-76	Medius
250 Hz mouse	0-20	Equal
125 Hz mouse	0-2	Equal

Gaps >1.5× the report interval, in 15 s

Mouse	Stock	Result
1 kHz mouse	0	Equal
500 Hz mouse	1-24	Medius
250 Hz mouse	0	Equal
125 Hz mouse	0	Equal

Reports >10% early or late, in 2 minutes

Mouse	Stock	Medius	Result
500 Hz mouse	287	2	Medius

Gaps >1.5× the report interval, in 2 minutes

Mouse	Stock	Medius	Result
500 Hz mouse	105	0	Medius

Keyboard reports >10% early or late, in 15 s

Keyboard	Stock	Medius	Result
1 kHz keyboard	0	0-2	Equal
125 Hz keyboard	0	0	Equal

Report latency

Each native report is timed from the emulator queuing it to the PC receiving the clone's copy. The emulator runs 1,000 ppm slow, so its reports land at every point between polls. Plugged straight into a PC, a native report waits half the native interval on average (4 ms for a 125 Hz mouse).

Report latency, p50

Mouse	Stock	Medius	Result
1 kHz mouse	1.43-1.44 ms	1.02-1.04 ms	Medius
500 Hz mouse	1.24-1.39 ms	1.50-1.51 ms	StockStock defect
250 Hz mouse	1.22-1.35 ms	2.52 ms	StockStock defect
125 Hz mouseStock's clone declares 1 ms, the mouse 8 ms (see Poll interval)	1.32-1.37 ms	4.50-4.52 ms	StockStock defect

Report latency, p95

Mouse	Stock	Medius	Result
1 kHz mouse	2.05-2.61 ms	1.46-1.48 ms	Medius
500 Hz mouse	1.99-2.03 ms	2.41 ms	StockStock defect
250 Hz mouse	1.90-2.03 ms	4.31-4.32 ms	StockStock defect
125 Hz mouse	2.00-2.04 ms	8.11-8.12 ms	StockStock defect

Report latency, p99

Mouse	Stock	Medius	Result
1 kHz mouse	2.20-2.98 ms	1.51-1.52 ms	Medius
500 Hz mouse	2.19-2.20 ms	2.49 ms	StockStock defect
250 Hz mouse	2.15-2.18 ms	4.48 ms	StockStock defect
125 Hz mouse	2.17-2.20 ms	8.43 ms	StockStock defect

Report latency, fastest

Mouse	Stock	Medius	Result
1 kHz mouse	370-381 µs	501-502 µs	Stock
500 Hz mouse	335-340 µs	487-504 µs	StockStock defect
250 Hz mouse	318-326 µs	502-514 µs	StockStock defect
125 Hz mouse	328-492 µs	499-510 µs	StockStock defect

Reads while injecting

The emulated mouse sends its next report only after the box reads the last one, so the count is how often the box read the mouse. Read every millisecond, a 1 kHz mouse gives 15,500 reports in 15.5 s and 5,500 in 5.5 s.

Reports read from a 1 kHz mouse in about 15.5 s

Stock km.moveMedius MOVE

Load	Stock`km.move`	Medius`MOVE`	Result
Injecting 1,000 moves/s	7,133-7,201	15,540-15,584	MediusStock defect

Reports read from a 1 kHz counting mouse in 15.5 s

Stock km.moveMedius MOVE

Moves sent	Stock`km.move`	Medius`MOVE`	Result
None	15,500	15,500	Equal
1,000/s	6,877	15,500	Medius
500/s	5,238	15,500	Medius
125/s	7,020	15,499	Medius

Reports read from a 1 kHz mouse moving at a varying speed, in 15.5 s

Stock km.moveMedius MOVE

Moves sent	Stock`km.move`	Medius`MOVE`	Result
1,000/s	7,180-7,227	15,500	Medius
500/s	6,965-7,028	15,500	Medius
125/s	7,190-7,287	15,500	Medius

Reports read from a 1 kHz mouse in 15.5 s, injecting 1,000 moves/s

Stock km.moveMedius MOVE

Mouse	Stock`km.move`	Medius`MOVE`	Result
Moving 1 count every report	15,493	15,500	Medius
Moving 100 counts every report	15,495	15,500	Medius
Moving 1 count, then -1, alternating	15,496	15,500	Medius

Reports read from a 1 kHz mouse moving at a varying speed, in 5.5 s

Commands sent	Stock	Medius	Result
10 moves/s	3,003	5,500	Medius
30 moves/s	3,010	5,500	Medius
1,000 zero-count moves/s	5,496	5,500	Medius
100 queries/s	5,500	5,500	Equal

PC to real device

Requests and reports the PC sent the real device, through its clone.

What reaches the real device

PC sends	Stock	Medius	Result
SET_PROTOCOL(boot)	Passed on	Passed on	Equal
Endpoint halt, then clear	Passed on	Passed on	Equal
Switch to alternate setting 1, then back	Passed on	Passed on	Equal
Switch to configuration 2, then back	Clone reconnects instead	Passed on	MediusStock defect
Keyboard LED report	Passed on	Passed on	Equal
20 HID output reports	Passed on	Passed on	Equal

Resets the real device gets

PC sends	Stock	Medius	Result
One bus reset	Twice	Once	Differs
Hub port off for 1 s	Twice	Once	Differs

Real device to PC

A real device stalling its endpoint, one replying to polls with empty packets, and a vendor interface streaming a counter.

What reaches the PC

Native traffic	Stock	Medius	Result
A STALL on its interrupt endpoint	Reaches the PC	Reaches the PC	Equal
Empty packets on idle polls	Reaches the PC	Reaches the PC	Equal
Vendor stream at 1,000 packets/s	Reaches the PC	Reaches the PC	Equal

Game pads

Three emulated pads, each moving its left stick through set values for 1.5 s.

Stick values on the PC

Pad	Stock	Medius	Result
Xbox 360 pad (XInput)	Unchanged	Unchanged	Equal
Xbox One pad (GIP)	Unchanged	Unchanged	Equal
HID pad	Unchanged	Unchanged	Equal

PC output reaching the pad

Pad	Stock	Medius	Result
Xbox 360 pad, LED command	Reaches the pad	Reaches the pad	Equal
Xbox One pad, start-up packets	Reaches the pad	Reaches the pad	Equal