STT GDC Chennai 4 is 17 MW under construction — the larger of the two pipeline buildings, and 5.7 times the entire operating capacity of Chennai 1. With Chennai 3 at 15 MW it makes a 32 MW pipeline against a 29 MW operating business, which is the answer to Chennai’s supply shortage. It is also 25% of the 68 MW city headline. No handover date, rack count, floor area or PUE is published, so the answer exists and its timing does not.
1At a glance
2The larger half of the answer
Chennai’s shortage has one obvious solution under construction, and this building is the bigger part of it.
| Measure | MW | Reads as |
|---|---|---|
| Chennai 3 | 15 | the first pipeline building |
| Chennai 4 | 17 | the larger of the two |
| Pipeline total | 32 | 110% of the operating base |
| Operating today | 29 | Chennai 1 and 2 |
| If both land | 61 | STT’s Chennai business more than doubles |
| Headline today | 68 | already includes all of it |
That last line is the whole STT pattern in one table. The company’s published Chennai figure already assumes these buildings exist. If they land, the headline becomes true. If they do not, the headline was never capacity.
For the market the arithmetic is straightforward: 32 MW arriving roughly doubles one operator’s presence and adds about 10% to Tamil Nadu’s counted capacity. That is enough to move rents in a market this tight, and it is entirely dependent on a date no one has published.
3Two buildings, one programme
Chennai 3 and 4 are being built as a pair under a single ₹4,200 crore multi-campus announcement.
| Reading | Cost per megawatt | Plausible? |
|---|---|---|
| The ₹4,200 crore is for these two buildings only | ₹131 crore a MW | no — four times the Indian range |
| It funds a broader multi-campus programme | around ₹42 crore a MW at 100 MW | yes — at the top of the market range |
| It includes land and power infrastructure | unquantifiable from public material | likely, and it is why the ratio does not divide |
The lesson is procedural rather than financial: programme announcements and building cards are different data, and dividing one by the other produces a number that looks like diligence and is not. Indian build costs cluster between ₹30 and ₹45 crore a megawatt; anything far outside that is a scope mismatch, not a discovery.
Two buildings, one programme, no schedule. That is the state of the Chennai pipeline, and it is why this registry reports both figures and refuses to average them.
4Procurement
5Limits and open questions
- No handover date. The defining absence, shared with Chennai 3.
- No racks, floor area or PUE.
- No indication which building delivers first. The numbering suggests Chennai 3, but nothing states it.
- Programme investment is unscoped and cannot be attributed to this building.
- Counted at zero, correctly.
- What would close it. A handover sequence for the pair. One line would let every tenant in Chennai plan.
6Sources
Sources: STT GDC India Chennai city page, STT GDC India Chennai multi-campus expansion announcement, STT GDC India facility pages for Chennai, STT GDC India corporate site, and Indian market commentary on Chennai data centre supply and rents.