GATE | Operating Systems

OS Algorithm Visualizer

CPU Scheduling, Page Replacement, and more — step through every algorithm with animated visualizations built for GATE CS exam prep.

Algorithm

Choose a scheduling policy to simulate

Basic

Priority

Multi-Queue

Processes run strictly in order of arrival. Simple, but a long process at the front delays everything behind it (convoy effect).

Processes

4 processes

	PID	Arrival	Burst	Mode

t = 022

Gantt Chart

CPU, IO, normalized, and combined views

⇄3 context switches

CPU Execution (Per-Unit)

22 blocks

0246810121416182022

Ready Queue

t=0 — 1 waiting

P1 — 5

CPU Status

Executing P1

One process, one CPU — no context switch in progress.

Ready Queue

Empty

Incoming

P2 @ t=1P3 @ t=2P4 @ t=3

Completed

None yet

Live Statistics

Recomputed instantly for the selected algorithm

Avg Waiting

5.75

Avg Turnaround

11.25

Avg Response

5.75

Avg Completion

12.75

Scheduling Length

22units

Throughput

0.182/unit

CPU Utilization

100%

Context Switches

Idle Time

0units

Total Time

22units

PID	Arrival	CPU Burst	Priority	CT	TAT	WT	RT
P1	0	5	2	5	5	0	0
P2	1	3	1	8	7	4	4
P3	2	8	3	16	14	6	6
P4	3	6	4	22	19	13	13

Educational Log

Why the scheduler made each decision, revealed as the clock advances

t=0At t=0, Process P1 is selected — it is next in arrival order (arrived at t=0). Runs to completion at t=5.