Energy
How much electricity a Drupflare site uses against the hosting it replaces, and where the saving comes from. Energy Per View and Fleet Energy extend the model; Environment turns the totals into carbon and water, and Economics prices them. Every figure carries a label defined on Impact. Numbered citations such as [1] refer to the References list on Impact.
Pages
- Production Baseline: the conventional host the saving is measured against.
- Operating States and Where the Saving Comes From: operating states and where the saving comes from.
- Where The Figures Come From: model inputs and the two hosts.
- Energy Per Request: the per-request figure, the two runtimes at matched load, logged-in views, bindings and the idle floor.
Energy Savings
Total energy of one site over a year, idle included, for drupflare and for a production deployment. A
conventional deployment draws power whether or not anyone visits; drupflare's figure is the CPU time
its views use, logged-in views included. Every cell is derived (modelled): no source sizes a
production node, so the production shapes are modelled, and drupflare's energy is derived from
measured CPU time on the traffic mix. A month is a twelfth of each figure. Generated by
bun scripts/economics/perview.ts.
This is the sleeping state, a site that holds nothing between requests. A site kept warm, or one that wakes cold, draws more. Operating States prices both, and the saving against production stays above 99.5% in every state.
| views a month | drupflare, energy a year | production, energy a year | energy saved a year | saving against production | saving against peak-sized |
|---|---|---|---|---|---|
| 10,000 | 0.525 Wh | 224 kWh | 224 kWh | 426,766x, 99.9998% | 742,503x, 99.9999% |
| 100,000 | 2.14 Wh | 224 kWh | 224 kWh | 104,856x, 99.9990% | 182,432x, 99.9995% |
| 1,000,000 | 18.3 Wh | 224 kWh | 224 kWh | 12,274x, 99.9919% | 21,355x, 99.9953% |
| 10,000,000 | 180 Wh | 224 kWh | 224 kWh | 1,249x, 99.9199% | 2,173x, 99.9540% |
| 30,000,000 | 538 Wh | 224 kWh | 224 kWh | 417x, 99.7601% | 725x, 99.8621% |
Production is three regions with a high-availability web pair and database pair in each, sized at 15% utilisation. Peak-sized is the same three regions with 8-vCPU nodes at 10%, 390 kWh a year. The multiple is the ratio of the two totals. It grows as traffic falls because drupflare's total has no idle term, so quote the percentage.
What those savings compare to, at 10,000,000 views per site per month, derived from the same totals
by bun scripts/economics/comparison.ts --md:
| sites | against | electricity | carbon | servers not built |
|---|---|---|---|---|
| 1 | production | one US home for 7 days | 180 lb CO2e | 1/14 of one server not built |
| 1 | peak-sized production | one US home for 13 days | 330 lb CO2e | a seventh of one server not built |
| 10 | production | one US home for 75 days | 1,800 lb CO2e | a half of one server not built |
| 10 | peak-sized production | one US home for 131 days | 3,300 lb CO2e | 1 server not built |
| 100 | production | 2 US homes for a year | 1 car off the road | 7 servers not built |
| 100 | peak-sized production | 3 US homes for a year | 3 cars off the road | 15 servers not built |
| 1,000 | production | 20 US homes for a year | 18 cars off the road | 75 servers not built |
| 1,000 | peak-sized production | 36 US homes for a year | 32 cars off the road | 150 servers not built |
Every figure is rounded down, so each is a floor. A server is the share of one 640-thread host the
model assigns to the deployment: 12 nodes at 4 or 8 vCPU each, counted in whole servers and, below
one, as the largest unit fraction that fits, derived (modelled). The host is the SPECpower result
for a Dell PowerEdge R6725 with two AMD EPYC 9845 chips, 320 cores and 640 hardware threads, which
idles at 135 W and draws 711 W at 100% load [1]. A US home is the EIA's 2022 average of 10,791 kWh
a year [2], and a passenger vehicle emits about 4.6 t of CO2 a year [3].