CPU Sizing
Table of Contents
There are two figures you need to bear in mind when choosing a server, concurrency and page load time. Concurrency is how many customers your server can support at any time. Individual page load time is how fast the page actual loads for a single customer.
It is possible to have:
- A slow page load time and low concurrency support (low clock speed CPU (GHz), few cores)
- A fast page load time, but low concurrency support (high clock speed CPU (GHz), few cores)
- A slow page load time, but high concurrency support (low clock speed CPU (GHz), lots of cores)
- A fast page load time and high concurrency support (high clock speed CPU (GHz), lots of cores)
You can choose your hardware based on this.
Concurrency
- A standard Magento demo store is capable of delivering roughly 230 uniques per GHz, per hour.
- A typical web store, with admin user activity, development activity, product addition/deletion can see this degrade by around 100%, to 115 uniques per GHz, per hour.
- A store with a poorly built/heavy template can further reduce the figure by another 100-200%, to 50 uniques per GHz, per hour.
We quote estimate figures based on a combination of 2. and 3. - but you can adjust to suit your store's build quality.
| Chassis | Total GHz | Visitors/Hour Peak | Visitors/Day Peak | Concurrent Visitors Peak | Sustained Visitors/Day |
|---|---|---|---|---|---|
| 8-Core | 28 | 1,610 | 16,100 | 187 | 4,025 |
| 16-Core | 72.8 | 4,186 | 41,860 | 485 | 10,465 |
| 28-Core | 83.2 | 4,784 | 47,840 | 555 | 11,960 |
| 32-Core | 92.8 | 5,336 | 53,360 | 619 | 13,340 |
| 40-Core | 120 | 6,900 | 69,000 | 800 | 17,250 |
| 56-Core | 145.6 | 8,372 | 83,720 | 971 | 20,930 |
| 64-Core | 166.4 | 9,568 | 95,680 | 1,109 | 23,920 |
| 384-Core | 844.8 | 4,8576 | 485,760 | 5,632 | 121,440 |
The total GHz figure can be obtained by multiplying the CPU clock speed against the number of logical cores.
Individual Page load time
A standard Magento demo store (CE or EE – with all caches disabled) is capable of achieving average load times of:
| Chassis | CPU Speed* | Page Load Time (seconds) |
|---|---|---|
| 8-Core | 3.5 | 0.480 |
| 16-Core | 3.5 | 0.480 |
| 28-Core | 3.3 | 0.509 |
| 32-Core | 2.9 | 0.579 |
| 40-Core | 3.6 | 0.467 |
| 56-Core | 3.5 | 0.480 |
| 64-Core | 3 | 0.560 |
| 384-Core | 3.4 | 0.494 |
But again, a badly built/heavy template will cause this figure to increase exponentially. When we quote figures, we use the demo store template with sample data as an example.
* As Sonassi use the latest generation Intel server CPUs, the CPU speed quoted is that of the maximum sustained frequency the CPU can operate at