Partial fanout

[vrom911]

Part of #1468

---

• CHANGELOG updated or not needed
• Documentation updated or not needed
• Haddocks updated or not needed
• No new TODOs introduced or explained herafter

[github-actions]

Transaction costs

Sizes and execution budgets for Hydra protocol transactions. Note that unlisted parameters are currently using arbitrary values and results are not fully deterministic and comparable to previous runs.

Metadata
Generated at	2026-02-19 10:38:49.194657575 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νInitial	c8a101a5c8ac4816b0dceb59ce31fc2258e387de828f02961d2f2045	2652
νCommit	61458bc2f297fff3cc5df6ac7ab57cefd87763b0b7bd722146a1035c	685
νHead	13037f2898c01805ce688b11b4c85e203156836f41f493426f927aa5	13801
μHead	e345229dc8eacd102b643f6c130257598adae1bbf4f320840220c51b*	4451
νDeposit	ae01dade3a9c346d5c93ae3ce339412b90a0b8f83f94ec6baa24e30c	1102
νCRS	3bcbff46edf56d5ef00892289ce9e81da5a4b911b7dc6e1eb8adfc8e	2214

• The minting policy hash is only usable for comparison. As the script is parameterized, the actual script is unique per head.

Init transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	5004	12.63	3.94	0.50
2	5204	15.30	4.78	0.54
3	5406	17.75	5.55	0.57
5	5807	22.31	6.95	0.64
10	6811	34.77	10.85	0.81
35	11840	97.91	30.43	1.68

Commit transaction costs

This uses ada-only outputs for better comparability.

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	561	2.44	1.16	0.20
2	742	3.38	1.73	0.22
3	919	4.36	2.33	0.24
5	1283	6.41	3.60	0.28
10	2182	12.13	7.25	0.40
54	10066	98.61	68.52	1.88

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	57	525	22.52	6.60	0.40
2	113	636	28.15	8.29	0.47
3	170	747	33.76	9.97	0.53
4	228	858	39.43	11.66	0.59
5	282	969	45.74	13.52	0.66
6	338	1081	53.49	15.74	0.74
7	394	1192	56.95	16.84	0.78
8	450	1303	64.18	18.97	0.86
9	506	1414	69.89	20.73	0.93
10	560	1525	80.72	23.68	1.04

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	1925	22.39	7.22	0.47
2	2056	23.31	8.21	0.49
3	2200	24.00	9.14	0.51
5	2578	27.81	11.68	0.57
10	3379	35.09	17.41	0.71
50	9632	88.82	61.86	1.74

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	735	20.87	6.87	0.40
2	990	22.52	8.09	0.43
3	1117	22.58	8.89	0.45
5	1634	25.87	11.52	0.51
10	2581	29.87	17.51	0.63
50	11079	83.03	99.76	2.03

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	808	35.55	28.62	0.68
2	1068	37.86	30.01	0.72
3	1257	39.55	31.25	0.75
5	1844	44.25	34.35	0.84
10	2983	55.15	42.18	1.03
35	8524	98.19	92.81	1.99

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	2876	40.50	35.01	0.86
2	3086	43.09	37.01	0.90
3	3282	46.24	39.18	0.95
5	3594	49.95	42.73	1.02
10	4157	58.57	51.40	1.18
29	7085	99.56	86.80	1.89

Abort transaction costs

There is some variation due to the random mixture of initial and already committed outputs.

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	5003	39.21	12.27	0.78
2	5159	52.38	16.54	0.92
3	5213	58.72	18.42	0.99
4	5430	75.35	23.77	1.17
5	5633	89.44	28.40	1.33
6	5540	89.94	28.33	1.32

FanOut transaction costs

Involves spending head output and burning head tokens. Uses ada-only UTXO for better comparability.

Parties	UTxO	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
10	0	0	5076	31.75	36.95	0.90
10	1	57	5111	36.04	39.29	0.95
10	5	285	5246	53.34	48.67	1.16
10	14	795	5550	95.42	70.43	1.67

End-to-end benchmark results

This page is intended to collect the latest end-to-end benchmark results produced by Hydra's continuous integration (CI) system from the latest master code.

Please note that these results are approximate as they are currently produced from limited cloud VMs and not controlled hardware. Rather than focusing on the absolute results, the emphasis should be on relative results, such as how the timings for a scenario evolve as the code changes.

Generated at 2026-02-19 10:41:51.475429425 UTC

Baseline Scenario

Number of nodes	1
Number of txs	300
Avg. Confirmation Time (ms)	5.453143180
P99	7.459510139999998ms
P95	6.5492295ms
P50	5.2501750000000005ms
Number of Invalid txs	0

Three local nodes

Number of nodes	3
Number of txs	900
Avg. Confirmation Time (ms)	33.810942167
P99	52.82333476999999ms
P95	44.45214694999999ms
P50	32.574135999999996ms
Number of Invalid txs	0

[github-actions]

Transaction cost differences

Script summary

Name	Size (Bytes)
μHead	$${\color{green}-833.00}$$
νCommit	-
νDeposit	-
νHead	$${\color{green}-798.00}$$
νInitial	-

Init transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	$${\color{green}-833.00}$$	2.24	0.65	$${\color{green}-0.02}$$
2	$${\color{green}-833.00}$$	2.66	0.78	$${\color{green}-0.01}$$
3	$${\color{green}-833.00}$$	3.05	0.89	-
5	$${\color{green}-833.00}$$	3.88	1.15	-
10	$${\color{green}-833.00}$$	5.85	1.74	+0.02

Commit transaction costs

UTxO	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	-	-
2	-	-	-	-
3	-	-	-	-
5	-	-	-	-
10	-	-	-	-
54	-	-	-	-

CollectCom transaction costs

Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	-	-	$${\color{green}-2.50}$$	$${\color{green}-0.66}$$	$${\color{green}-0.03}$$
2	-	-	$${\color{green}-5.91}$$	$${\color{green}-1.53}$$	$${\color{green}-0.06}$$
3	-	-	$${\color{green}-8.25}$$	$${\color{green}-2.13}$$	$${\color{green}-0.09}$$
4	-	-	$${\color{green}-13.17}$$	$${\color{green}-3.36}$$	$${\color{green}-0.13}$$
5	-	-	$${\color{green}-9.94}$$	$${\color{green}-2.65}$$	$${\color{green}-0.10}$$
6	-	-	$${\color{green}-12.78}$$	$${\color{green}-3.36}$$	$${\color{green}-0.13}$$
7	-	-	$${\color{green}-30.43}$$	$${\color{green}-7.68}$$	$${\color{green}-0.31}$$
8	-	-	$${\color{green}-31.47}$$	$${\color{green}-7.99}$$	$${\color{green}-0.31}$$
9	-	-	$${\color{green}-16.01}$$	$${\color{green}-4.27}$$	$${\color{green}-0.16}$$

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	140	$${\color{green}-1.58}$$	$${\color{green}-0.40}$$	$${\color{green}-0.01}$$
2	140	$${\color{green}-2.56}$$	$${\color{green}-0.58}$$	$${\color{green}-0.01}$$
3	140	$${\color{green}-2.91}$$	$${\color{green}-0.62}$$	$${\color{green}-0.02}$$
5	140	$${\color{green}-4.76}$$	$${\color{green}-0.98}$$	$${\color{green}-0.04}$$
10	140	$${\color{green}-7.37}$$	$${\color{green}-1.38}$$	$${\color{green}-0.06}$$

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	72	$${\color{green}-1.67}$$	$${\color{green}-0.44}$$	$${\color{green}-0.01}$$
2	140	$${\color{green}-2.62}$$	$${\color{green}-0.60}$$	$${\color{green}-0.02}$$
3	140	$${\color{green}-3.25}$$	$${\color{green}-0.70}$$	$${\color{green}-0.02}$$
5	276	$${\color{green}-4.46}$$	$${\color{green}-0.72}$$	$${\color{green}-0.03}$$
10	616	$${\color{green}-7.93}$$	$${\color{green}-0.21}$$	$${\color{green}-0.04}$$

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	+957	7.06	18.62	0.24
2	+549	6.93	18.59	0.22
3	+480	6.77	18.62	0.21
5	+616	6.64	18.97	0.22
10	+1229	5.95	21.19	0.26
34	+2591	3.41	40.72	0.43

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	2251	7.31	25.06	0.34
2	2250	7.17	25.61	0.34
3	2250	7.06	26.17	0.34
5	2250	6.75	27.28	0.35
10	2250	5.95	30.03	0.37

FanOut transaction costs

UTxO, Parties	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
(0, 10)	-	$${\color{green}-758.00}$$	13.44	30.84	0.3
(1, 10)	-	$${\color{green}-758.00}$$	15.24	32.22	0.32
(5, 10)	-	$${\color{green}-758.00}$$	23.55	38.09	0.43
(10, 10)	-	$${\color{green}-758.00}$$	36.19	46.03	0.59

[v0d1ch]

lgtm. I think the main concern is that we want to have any UTxO to commit/decommit in there when building the accumulator and I gave the reason in one of the comments.