The same H100 block is 50 days apart depending on the region you ask

AWS will tell you the earliest date a Capacity Block can start when you ask for one, and then it forgets. Nobody keeps the history. I do: every region that sells Capacity Blocks, every P and Trn instance family, every block length, sampled up to every 15 minutes since late July, with the record kept. This is the first readout. It covers the 19 days from August 23 to September 10, the period where all 11 regions were live and the error rate was under 1%. Later issues will be weekly.

The short version: the price never moves. The start date is the whole story, and it varies more by region than by anything else.

1. Same block, same price, 50 days apart

For a 7-day H100 block (p5.48xlarge), the median gap between the fastest and slowest region on the same day, among regions that had any offer at all, was 50 days. It was never below 40. H200 was the same: 51 days for p5en, 48 for p5e. The price in every one of those regions was identical within the US and identical outside it.

On September 10, an H100 7-day block started now in Ohio, Oregon, N. California, Tokyo and Sydney, in 5 days in Stockholm, in 14 in São Paulo, in 27 in London, and in 47 in Mumbai.

Region flexibility is the biggest lever a buyer has, and it costs nothing. Most teams only ever ask one region.

This is the aggregate view. The per-region, per-instance, per-block-length breakdown behind it (140 combinations, daily since late August) is held back. If you need yours, email me and I'll send its history.

2. H200 is the scarce chip right now, not B200

Share of days each instance type was open, queued, or sold out, 7-day blocks, all regions:

Three things to take from it. H100 is the loose SKU: if you can run on p5 and you're region-flexible, you can usually start today. H200 in either flavor is a queue, not an on-demand resource: sold out on 30 to 37% of days, and 14 of the 44 combinations that were sold out every single day of the window are H200. B200 was never sold out on any day in any region, though it's rarely open either: you wait about three weeks. A100 is scarcer than people assume, and Trainium blocks have not appeared once, in any region, since sampling began in July.

3. Where you ask matters: N. Virginia is one of the tightest regions there is

Share of days each region was open, queued, or sold out, 7-day blocks, all instance types:

us-east-1, the region most teams default to, was sold out on 36% of days. Only Stockholm was worse. Oregon, one time zone over, was sold out on none. Every non-US region also prices H100 9% lower (section 6).

4. Quotes rot. Sold out sticks.

Take any region, instance and block length, note its earliest start, and come back in 7 days:

• 28% of the time it moved by a week or more. 9% of the time by two weeks or more.
• If it was open today, there is a 23% chance it's no longer open in a week. About 1 in 4.
• If it was sold out today, there is an 82% chance it's still sold out in a week. About 4 in 5. Day to day, a sold-out combination stays sold out 97% of the time.

The practical reading: a start date you looked up last week is a guess. And "we'll check again next week" is a bad plan for a sold-out combination, because it will almost certainly still be sold out.

5. Longer H200 blocks vanish. Longer H100 blocks don't.

Share of days a block was obtainable at all, by block length, all regions:

H100 is a deep pool: flat across lengths. H200 p5en is a shallow one: the calendar has gaps you can fit a week into but not a month. If you need H200 for four weeks, four 7-day blocks may start sooner than one 28-day block, at the same price per GPU-hour. 84-day blocks barely exist for anything; the long-commitment leg on AWS is not a Capacity Block. A100 blocks longer than a week are half gone, and 84-day A100 blocks never appeared.

6. The rate card, and the October reset

Not one per-GPU-hour price changed across 41 region-and-instance combinations since sampling began in late July. That isn't luck. AWS's pricing page says it in one sentence: "Reservation prices are updated regularly based on trends in supply and demand for EC2 Capacity Blocks. The current prices are scheduled to be updated next in October, 2026." Prices reset on a schedule. Between resets, the only thing that moves is the start date.

Data in data/fig6_rate_card.csv. Identical per hour across 1, 7, 14, 28 and 84-day blocks; no volume or duration discount.

Two things worth knowing. H100 and H200 p5en are 9% cheaper in every non-US region we watch (Tokyo, Seoul, Mumbai, Sydney, Stockholm, London, São Paulo). And AWS charges the rate at the time of purchase even if the block starts after a reset, so anything booked before the October update is booked at today's price. The two 2026 increases reported so far were about 15% in January and about 20% in July.

7. This week, September 4 to 10

Of the 140 region, instance and block-length combinations tracked this week: 33 open, 74 queued, 33 sold out. 25 changed state versus the week before. Prices changed in none.

Got worse

• N. Virginia, H200 (p5en), 7-day: start in 5 days → nothing before the end of the horizon.
• N. California, H200 (p5en), every length: start now to 29 days → 47 days.
• London, H200 (p5e), 1-day: 7 days → 49 days.
• N. Virginia, A100 80GB, 7-day: 31 days → 54 days.

Got better

• N. Virginia, B200, 7 and 28-day: 45 days → 5 days. The biggest reopen recorded so far.
• São Paulo, H200 (p5e), 28-day: 15 days → start now.
• Seoul, B300, 1 and 7-day: 7 days → start now.
• N. Virginia, B300, 1 and 7-day: sold out → 3 to 4 days.

Data in data/fig7_this_week.json. Later issues lead with this section.

8. What to do with this if you're buying capacity

1. Decide region flexibility first. It's worth up to 50 days on the same block at the same price. If data gravity pins you to one region, that's the most expensive constraint you have; know that you're paying it.
2. Book when it's open. One in four open combinations closes within a week. Four in five sold-out ones stay that way. Waiting on a sold-out combination is not a plan.
3. Treat H200 as a queue and B200 as available. And if you're on A100 blocks, plan the move now, not when the pool disappears.
4. For H200, check shorter blocks. Chained 7-day blocks can start weeks before one 28-day block at the same price per GPU-hour.
5. Don't plan on Trainium blocks. They have not appeared once.

9. What people say

The most-upvoted r/aws thread about GPUs this year is someone who "checked every single region" for a P5 by hand and found nothing. Another asks, "is there a way to view the availability of the instances? can't possibly expect people to keep trying to provision, it doesn't make sense and it's not a good UX." An engineer costing an H200 experiment last month wrote: "capacity is scarce, so you'll use whichever AZ has it." This series is the answer to those three posts.

About the data

Everything here is my own read-only sampling of AWS Capacity Block offerings across all 11 regions that sell them, up to every 15 minutes, since late July 2026. Statistics use August 23 to September 10, the period with all regions live and errors under 1%. API errors and throttles are excluded and never counted as "no capacity." All figures are single-instance offers; larger block sizes are not covered here. Open, queue and sold out are defined once, in section 2, and used the same way everywhere. Combinations observed on fewer than 7 days are excluded from share-of-days statistics.

What's published and what's held. The tables above are aggregates. The underlying record is 140 region, instance and block-length combinations with a daily status and earliest start since late August, plus the sampling behind it. That breakdown, the per-combination history, and reopen alerts are held back.

Need one instance, one region, one block length? Email williambishop.cs@gmail.com with the three and I'll send its history and where it stands today. If your team plans training runs against Capacity Blocks, I'd like to compare notes on how you do it.

Next issue: week of September 11 to 17.