CPU ticks are the heartbeat of your computer. Understanding how they work is crucial for understanding why Vim is so fast and why other editors are slow.
What is a CPU Tick?#
The Clock Cycle#
1
2
3
4
5
|
// Every CPU instruction takes a certain number of clock cycles
mov eax, 1 // 1 clock cycle
add eax, ebx // 1 clock cycle
cmp eax, 0 // 1 clock cycle
jne loop_start // 1-3 clock cycles (branch prediction)
|
A CPU tick is one clock cycle of the processor. Modern CPUs run at billions of ticks per second (GHz).
1
2
3
4
5
6
|
# Modern CPU specifications
CPU: Intel Core i7-12700K
Base Clock: 3.6 GHz = 3,600,000,000 ticks per second
Boost Clock: 5.0 GHz = 5,000,000,000 ticks per second
# Each tick = 0.2 nanoseconds at 5 GHz
|
Every nanosecond matters when you’re processing millions of operations.
How Vim Uses CPU Ticks Efficiently#
Vim’s Optimized Operations#
1
2
3
4
5
6
7
8
|
// Vim's character processing - highly optimized
int vim_isword(int c)
{
return (c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c == '_';
}
|
This function takes ~3 CPU ticks to execute.
Vim’s Memory Management#
1
2
3
4
5
6
7
8
9
10
11
|
// Vim's buffer management - zero-copy operations
char_u *vim_strchr(char_u *str, int c)
{
while (*str)
{
if (*str == c)
return str;
str++;
}
return NULL;
}
|
Vim avoids memory allocations and copies whenever possible.
The Tick Budget Problem#
Modern Editors: Tick Waste#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
// This is what modern editors do
function processText(text) {
// 1. Parse text into AST (1000+ ticks)
const ast = parseText(text);
// 2. Apply syntax highlighting (5000+ ticks)
const highlighted = applySyntaxHighlighting(ast);
// 3. Update DOM (2000+ ticks)
updateDOM(highlighted);
// 4. Trigger reflow (1000+ ticks)
triggerReflow();
// Total: 9000+ ticks for simple text editing
}
|
Modern editors waste thousands of ticks on unnecessary operations.
Vim: Tick Efficiency#
1
2
3
4
5
6
7
8
9
10
11
12
13
|
// This is what Vim does
void vim_insert_char(int c)
{
// 1. Insert character (5 ticks)
insert_char_at_cursor(c);
// 2. Update display (10 ticks)
update_display();
// 3. Done (0 ticks)
// Total: 15 ticks for the same operation
}
|
Vim uses 600x fewer ticks than modern editors.
Tick Count Comparison#
1
2
3
4
5
6
7
8
9
10
11
|
# Opening a 10MB file
Vim: 50,000 ticks (0.01ms at 5GHz)
VS Code: 500,000,000 ticks (100ms at 5GHz)
# Typing a character
Vim: 15 ticks (0.003ms at 5GHz)
VS Code: 9,000 ticks (1.8ms at 5GHz)
# Syntax highlighting
Vim: 1,000 ticks (0.2ms at 5GHz)
VS Code: 5,000,000 ticks (1ms at 5GHz)
|
Vim is orders of magnitude more efficient with CPU ticks.
Why CPU Ticks Matter#
The Responsiveness Factor#
1
2
3
4
5
6
7
8
9
10
11
|
// Human perception thresholds
16ms = 60 FPS (smooth animation)
8ms = 120 FPS (very smooth)
4ms = 240 FPS (ultra smooth)
1ms = 1000 FPS (imperceptible)
// At 5GHz CPU
16ms = 80,000,000 ticks
8ms = 40,000,000 ticks
4ms = 20,000,000 ticks
1ms = 5,000,000 ticks
|
Vim stays well under the 1ms threshold for all operations.
The Battery Life Impact#
1
2
3
4
5
6
7
8
9
10
11
12
|
# CPU power consumption
Idle: 5W
Light load: 15W
Heavy load: 45W
# Tick efficiency impact
Vim: Light load (15W)
VS Code: Heavy load (45W)
# Battery life difference
Vim: 8 hours
VS Code: 3 hours
|
Vim’s tick efficiency translates to 2.5x better battery life.
The Memory Access Pattern#
Vim’s Cache-Friendly Design#
1
2
3
4
5
|
// Vim processes text sequentially
for (char *p = buffer_start; p < buffer_end; p++) {
// Sequential memory access - CPU cache friendly
process_char(*p);
}
|
Sequential access maximizes CPU cache efficiency.
Modern Editors: Cache Misses#
1
2
3
4
5
6
7
8
|
// Modern editors jump around memory
function updateSyntaxHighlighting() {
// Random memory access patterns
ast.nodes.forEach((node) => {
// Cache miss on every node
updateNode(node);
});
}
|
Random access patterns cause cache misses and waste ticks.
The Branch Prediction Advantage#
Vim’s Predictable Branches#
1
2
3
4
5
6
7
8
9
|
// Vim's character processing - predictable branches
if (c >= 'a' && c <= 'z') {
// This branch is taken 26/256 times - predictable
return true;
}
if (c >= 'A' && c <= 'Z') {
// This branch is taken 26/256 times - predictable
return true;
}
|
Predictable branches allow CPU to prefetch instructions.
Modern Editors: Unpredictable Branches#
1
2
3
4
5
6
7
8
|
// Modern editors have unpredictable branches
if (node.type === "function") {
// Unpredictable - depends on code structure
processFunction(node);
} else if (node.type === "class") {
// Unpredictable - depends on code structure
processClass(node);
}
|
Unpredictable branches cause CPU pipeline stalls.
Vim’s Philosophy: Minimal Operations#
1
2
3
4
5
6
7
8
9
10
11
|
// Vim does only what's necessary
void vim_move_cursor(int direction)
{
// 1. Update cursor position (2 ticks)
cursor_pos += direction;
// 2. Update display (5 ticks)
redraw_cursor();
// Total: 7 ticks
}
|
Modern Editors: Maximum Operations#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
|
// Modern editors do everything
function moveCursor(direction) {
// 1. Update cursor position
cursor.pos += direction;
// 2. Update syntax highlighting
updateSyntaxHighlighting();
// 3. Update autocomplete
updateAutocomplete();
// 4. Update error checking
updateErrorChecking();
// 5. Update minimap
updateMinimap();
// 6. Update breadcrumbs
updateBreadcrumbs();
// 7. Update status bar
updateStatusBar();
// 8. Update sidebars
updateSidebars();
// Total: 1000+ ticks
}
|
Vim does 1/100th the work of modern editors.
The Bottom Line#
CPU ticks matter because:
- Responsiveness: Fewer ticks = faster response
- Battery Life: Fewer ticks = less power consumption
- Heat: Fewer ticks = less heat generation
- Performance: Fewer ticks = more CPU available for other tasks
Vim’s efficiency with CPU ticks is why it:
- Starts instantly (50,000 ticks vs 500,000,000)
- Types smoothly (15 ticks vs 9,000)
- Uses minimal resources (Light load vs Heavy load)
- Works on any hardware (Even 20-year-old computers)
Stop wasting CPU ticks. Use Vim.