opexopt

Sample workspace · Example data

How a decision is reached.

Simulated for an anonymized client. Your workspace runs the same steps on your own demand, prices, and limits.

1 The company

An HPC startup in energy, between its Series A and Series B. Its researchers run physics simulations on rented cloud servers. The money raised lasts 36 months, and the hiring plan grows the team from 30 to 120 researchers in that time.

How should it pay for cloud compute so it costs least, even if hiring slows, with nothing owed after month 36?

2 Where the cost comes from

  1. Researchers30 → 120The hiring plan
  2. × Simulations19Per researcher, per month
  3. × Node-hours8Per simulation: one server for one hour
  4. × Price$5.65 → $7.58Per node-hour. Steps up in month 6; cause not yet known.
  5. = Compute$26k → $138kA month, month 1 → month 36

Hiring drives the cost: four times the researchers means four times the compute. Storage and the data platform come on top, and $648k of cloud credits pay the first months.

AWS regionPrices, results, and the decision below follow it.

3 The simulation

The simulator replays this demand hour by hour for 36 months, busy weekdays and quiet nights, and pays for it 59 ways: the five options below, and 54 variants of D with more or less commitment and Spot. It then runs every plan again with demand 15% below the forecast from month 12, as if hiring slowed: the low end of the plan's own forecast range. The on-demand price is the client's own, from step 2, in both regions. The discounts are AWS's published rates for us-east-1.

DiscountOff on-demand
1-year plan, paid monthly−28.3%
1-year plan, prepaid−33.1%
3-year plan, paid monthly−51.6%
Spot, can be interrupted−70%
30-day commitments Unquoted−29%

4 The options

OptionCost, 36 monthsIf demand falls 15%Largest paymentOwed after funding
A. On demandNo commitments: credits first, then on-demand prices.$3.69Mthe baseline$3.31M$197kmonth 35$0k
B. Prepaid 1-year plansOne-year Compute Savings Plans prepaid in months 11 and 23 for 55% of average compute, plus 30-day commitments for another 30%. The plan that was delivered. Rests on an unquoted 30-day rate.$3.14M−$547k vs A$2.83M$525kmonth 23$0k
C. One 3-year planOne three-year Compute Savings Plan from month 13 for 55% of average compute, paid monthly. The first draft.$3.21M−$476k vs A$2.90M$177kmonth 35$224k
D. Monthly-paid 1-year plansOne-year Compute Savings Plans in months 11 and 23 for 55% of average compute, paid monthly, with 50% of burst work on Spot.$2.89M−$800k vs A$2.61M$174kmonth 35$0k
E. 30-day commitments30-day commitments for 85% of average compute, resized every month, with 50% of burst work on Spot. Rests on an unquoted 30-day rate.$2.67M−$1.03M vs A$2.42M$147kmonth 35$0k
D at 65% coverage RecommendedLike D, with the one-year plans covering 65% of average compute instead of 55%.$2.86M−$828k vs A$2.59M$174kmonth 35$0k

Cost is the sum of every payment over the 36 months, so option A matches the plan on the home page.

B and C rebuild the home page's delivered plan and first draft on published discounts, with C sized to the same 55% coverage as the others, so their figures differ from the home page's.

Monthly cash out · each row on the same scale (largest bar $525k) · months 1–5 paid by credits
A. On demandA. On demand, month 1: $0kA. On demand, month 2: $0kA. On demand, month 3: $0kA. On demand, month 4: $0kA. On demand, month 5: $0kA. On demand, month 6: $67kA. On demand, month 7: $71kA. On demand, month 8: $75kA. On demand, month 9: $0kA. On demand, month 10: $57kA. On demand, month 11: $90kA. On demand, month 12: $55kA. On demand, month 13: $78kA. On demand, month 14: $103kA. On demand, month 15: $62kA. On demand, month 16: $111kA. On demand, month 17: $115kA. On demand, month 18: $80kA. On demand, month 19: $124kA. On demand, month 20: $129kA. On demand, month 21: $105kA. On demand, month 22: $137kA. On demand, month 23: $142kA. On demand, month 24: $116kA. On demand, month 25: $151kA. On demand, month 26: $155kA. On demand, month 27: $127kA. On demand, month 28: $165kA. On demand, month 29: $169kA. On demand, month 30: $140kA. On demand, month 31: $179kA. On demand, month 32: $183kA. On demand, month 33: $153kA. On demand, month 34: $193kA. On demand, month 35: $197kA. On demand, month 36: $161k$197kB. Prepaid 1-year plansB. Prepaid 1-year plans, month 1: $0kB. Prepaid 1-year plans, month 2: $0kB. Prepaid 1-year plans, month 3: $0kB. Prepaid 1-year plans, month 4: $0kB. Prepaid 1-year plans, month 5: $0kB. Prepaid 1-year plans, month 6: $67kB. Prepaid 1-year plans, month 7: $71kB. Prepaid 1-year plans, month 8: $75kB. Prepaid 1-year plans, month 9: $0kB. Prepaid 1-year plans, month 10: $57kB. Prepaid 1-year plans, month 11: $334kB. Prepaid 1-year plans, month 12: $16kB. Prepaid 1-year plans, month 13: $38kB. Prepaid 1-year plans, month 14: $62kB. Prepaid 1-year plans, month 15: $22kB. Prepaid 1-year plans, month 16: $70kB. Prepaid 1-year plans, month 17: $74kB. Prepaid 1-year plans, month 18: $38kB. Prepaid 1-year plans, month 19: $82kB. Prepaid 1-year plans, month 20: $86kB. Prepaid 1-year plans, month 21: $62kB. Prepaid 1-year plans, month 22: $95kB. Prepaid 1-year plans, month 23: $525kB. Prepaid 1-year plans, month 24: $55kB. Prepaid 1-year plans, month 25: $90kB. Prepaid 1-year plans, month 26: $94kB. Prepaid 1-year plans, month 27: $64kB. Prepaid 1-year plans, month 28: $102kB. Prepaid 1-year plans, month 29: $106kB. Prepaid 1-year plans, month 30: $76kB. Prepaid 1-year plans, month 31: $115kB. Prepaid 1-year plans, month 32: $119kB. Prepaid 1-year plans, month 33: $89kB. Prepaid 1-year plans, month 34: $128kB. Prepaid 1-year plans, month 35: $180kB. Prepaid 1-year plans, month 36: $149k$525kC. One 3-year planC. One 3-year plan, month 1: $0kC. One 3-year plan, month 2: $0kC. One 3-year plan, month 3: $0kC. One 3-year plan, month 4: $0kC. One 3-year plan, month 5: $0kC. One 3-year plan, month 6: $67kC. One 3-year plan, month 7: $71kC. One 3-year plan, month 8: $75kC. One 3-year plan, month 9: $0kC. One 3-year plan, month 10: $57kC. One 3-year plan, month 11: $90kC. One 3-year plan, month 12: $55kC. One 3-year plan, month 13: $59kC. One 3-year plan, month 14: $83kC. One 3-year plan, month 15: $42kC. One 3-year plan, month 16: $91kC. One 3-year plan, month 17: $96kC. One 3-year plan, month 18: $60kC. One 3-year plan, month 19: $104kC. One 3-year plan, month 20: $109kC. One 3-year plan, month 21: $85kC. One 3-year plan, month 22: $118kC. One 3-year plan, month 23: $122kC. One 3-year plan, month 24: $96kC. One 3-year plan, month 25: $131kC. One 3-year plan, month 26: $136kC. One 3-year plan, month 27: $107kC. One 3-year plan, month 28: $145kC. One 3-year plan, month 29: $149kC. One 3-year plan, month 30: $120kC. One 3-year plan, month 31: $159kC. One 3-year plan, month 32: $163kC. One 3-year plan, month 33: $133kC. One 3-year plan, month 34: $173kC. One 3-year plan, month 35: $177kC. One 3-year plan, month 36: $141k$177kD. Monthly-paid 1-year plansD. Monthly-paid 1-year plans, month 1: $0kD. Monthly-paid 1-year plans, month 2: $0kD. Monthly-paid 1-year plans, month 3: $0kD. Monthly-paid 1-year plans, month 4: $0kD. Monthly-paid 1-year plans, month 5: $0kD. Monthly-paid 1-year plans, month 6: $59kD. Monthly-paid 1-year plans, month 7: $62kD. Monthly-paid 1-year plans, month 8: $65kD. Monthly-paid 1-year plans, month 9: $0kD. Monthly-paid 1-year plans, month 10: $47kD. Monthly-paid 1-year plans, month 11: $70kD. Monthly-paid 1-year plans, month 12: $34kD. Monthly-paid 1-year plans, month 13: $56kD. Monthly-paid 1-year plans, month 14: $80kD. Monthly-paid 1-year plans, month 15: $39kD. Monthly-paid 1-year plans, month 16: $87kD. Monthly-paid 1-year plans, month 17: $91kD. Monthly-paid 1-year plans, month 18: $55kD. Monthly-paid 1-year plans, month 19: $99kD. Monthly-paid 1-year plans, month 20: $103kD. Monthly-paid 1-year plans, month 21: $79kD. Monthly-paid 1-year plans, month 22: $111kD. Monthly-paid 1-year plans, month 23: $110kD. Monthly-paid 1-year plans, month 24: $83kD. Monthly-paid 1-year plans, month 25: $117kD. Monthly-paid 1-year plans, month 26: $121kD. Monthly-paid 1-year plans, month 27: $92kD. Monthly-paid 1-year plans, month 28: $129kD. Monthly-paid 1-year plans, month 29: $133kD. Monthly-paid 1-year plans, month 30: $103kD. Monthly-paid 1-year plans, month 31: $141kD. Monthly-paid 1-year plans, month 32: $146kD. Monthly-paid 1-year plans, month 33: $115kD. Monthly-paid 1-year plans, month 34: $154kD. Monthly-paid 1-year plans, month 35: $174kD. Monthly-paid 1-year plans, month 36: $137k$174kE. 30-day commitmentsE. 30-day commitments, month 1: $0kE. 30-day commitments, month 2: $0kE. 30-day commitments, month 3: $0kE. 30-day commitments, month 4: $0kE. 30-day commitments, month 5: $0kE. 30-day commitments, month 6: $59kE. 30-day commitments, month 7: $62kE. 30-day commitments, month 8: $65kE. 30-day commitments, month 9: $0kE. 30-day commitments, month 10: $47kE. 30-day commitments, month 11: $61kE. 30-day commitments, month 12: $30kE. 30-day commitments, month 13: $52kE. 30-day commitments, month 14: $75kE. 30-day commitments, month 15: $34kE. 30-day commitments, month 16: $82kE. 30-day commitments, month 17: $85kE. 30-day commitments, month 18: $48kE. 30-day commitments, month 19: $91kE. 30-day commitments, month 20: $95kE. 30-day commitments, month 21: $70kE. 30-day commitments, month 22: $101kE. 30-day commitments, month 23: $105kE. 30-day commitments, month 24: $78kE. 30-day commitments, month 25: $111kE. 30-day commitments, month 26: $115kE. 30-day commitments, month 27: $85kE. 30-day commitments, month 28: $122kE. 30-day commitments, month 29: $125kE. 30-day commitments, month 30: $95kE. 30-day commitments, month 31: $132kE. 30-day commitments, month 32: $136kE. 30-day commitments, month 33: $105kE. 30-day commitments, month 34: $143kE. 30-day commitments, month 35: $147kE. 30-day commitments, month 36: $110k$147kD at 65% coverageRecommendedD at 65% coverage, month 1: $0kD at 65% coverage, month 2: $0kD at 65% coverage, month 3: $0kD at 65% coverage, month 4: $0kD at 65% coverage, month 5: $0kD at 65% coverage, month 6: $59kD at 65% coverage, month 7: $62kD at 65% coverage, month 8: $65kD at 65% coverage, month 9: $0kD at 65% coverage, month 10: $47kD at 65% coverage, month 11: $69kD at 65% coverage, month 12: $34kD at 65% coverage, month 13: $56kD at 65% coverage, month 14: $79kD at 65% coverage, month 15: $38kD at 65% coverage, month 16: $86kD at 65% coverage, month 17: $90kD at 65% coverage, month 18: $53kD at 65% coverage, month 19: $97kD at 65% coverage, month 20: $101kD at 65% coverage, month 21: $77kD at 65% coverage, month 22: $109kD at 65% coverage, month 23: $110kD at 65% coverage, month 24: $83kD at 65% coverage, month 25: $117kD at 65% coverage, month 26: $121kD at 65% coverage, month 27: $91kD at 65% coverage, month 28: $128kD at 65% coverage, month 29: $132kD at 65% coverage, month 30: $102kD at 65% coverage, month 31: $139kD at 65% coverage, month 32: $143kD at 65% coverage, month 33: $112kD at 65% coverage, month 34: $151kD at 65% coverage, month 35: $174kD at 65% coverage, month 36: $137k$174kM1M12M24M36

5 The decision

  1. Drop plans that would owe money after month 36: C.
  2. Drop plans that depend on a price not yet quoted: B and E.
  3. Of the 56 plans left, pick the one that stays closest to the cheapest, whether demand follows the forecast or falls 15%.

The result: D at 65% coverage, at most $3k above the cheapest either way. D, at 55%, is up to $32k above.

Recommended · us-east-1

D at 65% coverage

Decision required
Approve one-year Compute Savings Plans in months 11 and 23, each covering 65% of average compute, paid monthly. Run 50% of burst work on Spot with on-demand fallback.
Approver
CFO, with the Head of Engineering
Status
Pending approval

Pending quote E. 30-day commitments would cost $197k less if its 30-day rate is confirmed.

3 The simulation

The simulator replays this demand hour by hour for 36 months, busy weekdays and quiet nights, and pays for it 59 ways: the five options below, and 54 variants of D with more or less commitment and Spot. It then runs every plan again with demand 15% below the forecast from month 12, as if hiring slowed: the low end of the plan's own forecast range. The on-demand price is the client's own, from step 2, in both regions. The discounts are AWS's published rates for eu-central-1.

DiscountOff on-demand
1-year plan, paid monthly−23.9%
1-year plan, prepaid−29%
3-year plan, paid monthly−48.1%
Spot, can be interrupted−65%
30-day commitments Unquoted−29%

4 The options

OptionCost, 36 monthsIf demand falls 15%Largest paymentOwed after funding
A. On demandNo commitments: credits first, then on-demand prices.$3.69Mthe baseline$3.31M$197kmonth 35$0k
B. Prepaid 1-year plansOne-year Compute Savings Plans prepaid in months 11 and 23 for 55% of average compute, plus 30-day commitments for another 30%. The plan that was delivered. Rests on an unquoted 30-day rate.$3.19M−$500k vs A$2.87M$552kmonth 23$0k
C. One 3-year planOne three-year Compute Savings Plan from month 13 for 55% of average compute, paid monthly. The first draft.$3.25M−$443k vs A$2.93M$179kmonth 35$240k
D. Monthly-paid 1-year plansOne-year Compute Savings Plans in months 11 and 23 for 55% of average compute, paid monthly, with 50% of burst work on Spot.$2.97M−$716k vs A$2.68M$175kmonth 35$0k
E. 30-day commitments30-day commitments for 85% of average compute, resized every month, with 50% of burst work on Spot. Rests on an unquoted 30-day rate.$2.70M−$986k vs A$2.46M$149kmonth 35$0k
D at 65% coverage RecommendedLike D, with the one-year plans covering 65% of average compute instead of 55%.$2.95M−$737k vs A$2.67M$175kmonth 35$0k

Cost is the sum of every payment over the 36 months, so option A matches the plan on the home page.

B and C rebuild the home page's delivered plan and first draft on published discounts, with C sized to the same 55% coverage as the others, so their figures differ from the home page's.

Monthly cash out · each row on the same scale (largest bar $552k) · months 1–5 paid by credits
A. On demandA. On demand, month 1: $0kA. On demand, month 2: $0kA. On demand, month 3: $0kA. On demand, month 4: $0kA. On demand, month 5: $0kA. On demand, month 6: $67kA. On demand, month 7: $71kA. On demand, month 8: $75kA. On demand, month 9: $0kA. On demand, month 10: $57kA. On demand, month 11: $90kA. On demand, month 12: $55kA. On demand, month 13: $78kA. On demand, month 14: $103kA. On demand, month 15: $62kA. On demand, month 16: $111kA. On demand, month 17: $115kA. On demand, month 18: $80kA. On demand, month 19: $124kA. On demand, month 20: $129kA. On demand, month 21: $105kA. On demand, month 22: $137kA. On demand, month 23: $142kA. On demand, month 24: $116kA. On demand, month 25: $151kA. On demand, month 26: $155kA. On demand, month 27: $127kA. On demand, month 28: $165kA. On demand, month 29: $169kA. On demand, month 30: $140kA. On demand, month 31: $179kA. On demand, month 32: $183kA. On demand, month 33: $153kA. On demand, month 34: $193kA. On demand, month 35: $197kA. On demand, month 36: $161k$197kB. Prepaid 1-year plansB. Prepaid 1-year plans, month 1: $0kB. Prepaid 1-year plans, month 2: $0kB. Prepaid 1-year plans, month 3: $0kB. Prepaid 1-year plans, month 4: $0kB. Prepaid 1-year plans, month 5: $0kB. Prepaid 1-year plans, month 6: $67kB. Prepaid 1-year plans, month 7: $71kB. Prepaid 1-year plans, month 8: $75kB. Prepaid 1-year plans, month 9: $0kB. Prepaid 1-year plans, month 10: $57kB. Prepaid 1-year plans, month 11: $352kB. Prepaid 1-year plans, month 12: $16kB. Prepaid 1-year plans, month 13: $38kB. Prepaid 1-year plans, month 14: $62kB. Prepaid 1-year plans, month 15: $22kB. Prepaid 1-year plans, month 16: $70kB. Prepaid 1-year plans, month 17: $74kB. Prepaid 1-year plans, month 18: $38kB. Prepaid 1-year plans, month 19: $82kB. Prepaid 1-year plans, month 20: $86kB. Prepaid 1-year plans, month 21: $62kB. Prepaid 1-year plans, month 22: $95kB. Prepaid 1-year plans, month 23: $552kB. Prepaid 1-year plans, month 24: $55kB. Prepaid 1-year plans, month 25: $90kB. Prepaid 1-year plans, month 26: $94kB. Prepaid 1-year plans, month 27: $64kB. Prepaid 1-year plans, month 28: $102kB. Prepaid 1-year plans, month 29: $106kB. Prepaid 1-year plans, month 30: $77kB. Prepaid 1-year plans, month 31: $115kB. Prepaid 1-year plans, month 32: $119kB. Prepaid 1-year plans, month 33: $89kB. Prepaid 1-year plans, month 34: $128kB. Prepaid 1-year plans, month 35: $180kB. Prepaid 1-year plans, month 36: $149k$552kC. One 3-year planC. One 3-year plan, month 1: $0kC. One 3-year plan, month 2: $0kC. One 3-year plan, month 3: $0kC. One 3-year plan, month 4: $0kC. One 3-year plan, month 5: $0kC. One 3-year plan, month 6: $67kC. One 3-year plan, month 7: $71kC. One 3-year plan, month 8: $75kC. One 3-year plan, month 9: $0kC. One 3-year plan, month 10: $57kC. One 3-year plan, month 11: $90kC. One 3-year plan, month 12: $55kC. One 3-year plan, month 13: $60kC. One 3-year plan, month 14: $85kC. One 3-year plan, month 15: $44kC. One 3-year plan, month 16: $93kC. One 3-year plan, month 17: $97kC. One 3-year plan, month 18: $61kC. One 3-year plan, month 19: $106kC. One 3-year plan, month 20: $110kC. One 3-year plan, month 21: $86kC. One 3-year plan, month 22: $119kC. One 3-year plan, month 23: $123kC. One 3-year plan, month 24: $98kC. One 3-year plan, month 25: $132kC. One 3-year plan, month 26: $137kC. One 3-year plan, month 27: $108kC. One 3-year plan, month 28: $146kC. One 3-year plan, month 29: $151kC. One 3-year plan, month 30: $121kC. One 3-year plan, month 31: $160kC. One 3-year plan, month 32: $165kC. One 3-year plan, month 33: $135kC. One 3-year plan, month 34: $174kC. One 3-year plan, month 35: $179kC. One 3-year plan, month 36: $143k$179kD. Monthly-paid 1-year plansD. Monthly-paid 1-year plans, month 1: $0kD. Monthly-paid 1-year plans, month 2: $0kD. Monthly-paid 1-year plans, month 3: $0kD. Monthly-paid 1-year plans, month 4: $0kD. Monthly-paid 1-year plans, month 5: $0kD. Monthly-paid 1-year plans, month 6: $59kD. Monthly-paid 1-year plans, month 7: $62kD. Monthly-paid 1-year plans, month 8: $66kD. Monthly-paid 1-year plans, month 9: $0kD. Monthly-paid 1-year plans, month 10: $47kD. Monthly-paid 1-year plans, month 11: $72kD. Monthly-paid 1-year plans, month 12: $37kD. Monthly-paid 1-year plans, month 13: $58kD. Monthly-paid 1-year plans, month 14: $82kD. Monthly-paid 1-year plans, month 15: $41kD. Monthly-paid 1-year plans, month 16: $90kD. Monthly-paid 1-year plans, month 17: $94kD. Monthly-paid 1-year plans, month 18: $58kD. Monthly-paid 1-year plans, month 19: $102kD. Monthly-paid 1-year plans, month 20: $105kD. Monthly-paid 1-year plans, month 21: $81kD. Monthly-paid 1-year plans, month 22: $113kD. Monthly-paid 1-year plans, month 23: $114kD. Monthly-paid 1-year plans, month 24: $87kD. Monthly-paid 1-year plans, month 25: $121kD. Monthly-paid 1-year plans, month 26: $125kD. Monthly-paid 1-year plans, month 27: $95kD. Monthly-paid 1-year plans, month 28: $133kD. Monthly-paid 1-year plans, month 29: $137kD. Monthly-paid 1-year plans, month 30: $107kD. Monthly-paid 1-year plans, month 31: $145kD. Monthly-paid 1-year plans, month 32: $150kD. Monthly-paid 1-year plans, month 33: $119kD. Monthly-paid 1-year plans, month 34: $158kD. Monthly-paid 1-year plans, month 35: $175kD. Monthly-paid 1-year plans, month 36: $139k$175kE. 30-day commitmentsE. 30-day commitments, month 1: $0kE. 30-day commitments, month 2: $0kE. 30-day commitments, month 3: $0kE. 30-day commitments, month 4: $0kE. 30-day commitments, month 5: $0kE. 30-day commitments, month 6: $59kE. 30-day commitments, month 7: $62kE. 30-day commitments, month 8: $66kE. 30-day commitments, month 9: $0kE. 30-day commitments, month 10: $47kE. 30-day commitments, month 11: $64kE. 30-day commitments, month 12: $31kE. 30-day commitments, month 13: $53kE. 30-day commitments, month 14: $76kE. 30-day commitments, month 15: $35kE. 30-day commitments, month 16: $83kE. 30-day commitments, month 17: $86kE. 30-day commitments, month 18: $49kE. 30-day commitments, month 19: $93kE. 30-day commitments, month 20: $96kE. 30-day commitments, month 21: $71kE. 30-day commitments, month 22: $103kE. 30-day commitments, month 23: $106kE. 30-day commitments, month 24: $79kE. 30-day commitments, month 25: $113kE. 30-day commitments, month 26: $116kE. 30-day commitments, month 27: $86kE. 30-day commitments, month 28: $123kE. 30-day commitments, month 29: $127kE. 30-day commitments, month 30: $96kE. 30-day commitments, month 31: $134kE. 30-day commitments, month 32: $138kE. 30-day commitments, month 33: $107kE. 30-day commitments, month 34: $145kE. 30-day commitments, month 35: $149kE. 30-day commitments, month 36: $111k$149kD at 65% coverageRecommendedD at 65% coverage, month 1: $0kD at 65% coverage, month 2: $0kD at 65% coverage, month 3: $0kD at 65% coverage, month 4: $0kD at 65% coverage, month 5: $0kD at 65% coverage, month 6: $59kD at 65% coverage, month 7: $62kD at 65% coverage, month 8: $66kD at 65% coverage, month 9: $0kD at 65% coverage, month 10: $47kD at 65% coverage, month 11: $72kD at 65% coverage, month 12: $37kD at 65% coverage, month 13: $58kD at 65% coverage, month 14: $82kD at 65% coverage, month 15: $41kD at 65% coverage, month 16: $89kD at 65% coverage, month 17: $92kD at 65% coverage, month 18: $56kD at 65% coverage, month 19: $100kD at 65% coverage, month 20: $104kD at 65% coverage, month 21: $80kD at 65% coverage, month 22: $112kD at 65% coverage, month 23: $114kD at 65% coverage, month 24: $87kD at 65% coverage, month 25: $121kD at 65% coverage, month 26: $125kD at 65% coverage, month 27: $95kD at 65% coverage, month 28: $133kD at 65% coverage, month 29: $136kD at 65% coverage, month 30: $106kD at 65% coverage, month 31: $144kD at 65% coverage, month 32: $148kD at 65% coverage, month 33: $117kD at 65% coverage, month 34: $156kD at 65% coverage, month 35: $175kD at 65% coverage, month 36: $139k$175kM1M12M24M36

5 The decision

  1. Drop plans that would owe money after month 36: C.
  2. Drop plans that depend on a price not yet quoted: B and E.
  3. Of the 56 plans left, pick the one that stays closest to the cheapest, whether demand follows the forecast or falls 15%.

The result: D at 65% coverage, the cheapest in both cases. D, at 55%, is up to $20k above.

Recommended · eu-central-1

D at 65% coverage

Decision required
Approve one-year Compute Savings Plans in months 11 and 23, each covering 65% of average compute, paid monthly. Run 50% of burst work on Spot with on-demand fallback.
Approver
CFO, with the Head of Engineering
Status
Pending approval

Pending quote E. 30-day commitments would cost $249k less if its 30-day rate is confirmed.

What this rests on
  • Demand, prices, other charges, and credits come from the delivered plan shown on the home page: researchers × 19 jobs × 8 node-hours a month, at the client’s implied price per node-hour.
  • The implied price steps from $5.65 to $7.58 per node-hour in month 6; the cause is not yet explained by the client’s spend model.
  • The client’s price is used in both regions; the region changes only Savings Plan discounts, the Spot price share, and the interruption rate.
  • Burst profile (synthetic): weekday hours 09:00–19:00 at twice the night rate, weekends at 60%. Replaced by the client’s hourly usage when available.
  • Coverage is a share of the purchase month’s average hourly compute: 55% for the one-year plans (as delivered), 30% for option B’s 30-day layer, 85% for option E.
  • 30-day guaranteed commitments: 29% net discount (Archera headline, not region-specific) on an assumed 3-year No Upfront Compute Savings Plan; resized monthly. Needs a quote.
  • Spot: half of burst usage, restart 3 minutes, checkpoint every 15 minutes, independent interruptions at the research run’s hazard; correlated reclaims are not modeled yet.
  • Costs are plain cash totals: no discount rate, so a dollar paid in month 36 counts the same as one paid in month 1.
  • What if hiring slows: demand 15% below the forecast from month 12, the month after the first purchase. 15% is the low end of the delivered plan's own forecast range (its 10th percentile is 15% below the central forecast). Commitments bought after the drop are sized from actual usage.
  • Read option E with care: it leads only because of the unquoted 29% net discount, which the research flagged as probably blended across regions.
  • Spot looks better the more of the burst it takes because capacity shortfalls and correlated reclaims are not modeled yet; the grid’s best points sit at the edge of the Spot range tested.

Prices from the research run 2026.10.14.AWS.Arm.HPC.pricing.inputs. Your workspace runs the same comparison on your own demand.

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