eRacks Systems Tech Blog
Open Source Experts Since 1999
An AI Just Proved Fermat’s Last Theorem. Here Is What That Means for the Server You Buy Next
On September 4, Anthropic published the first complete, computer-checked proof of Fermat’s Last Theorem. Claude wrote it in Lean, a programming language built so a computer can verify every step of a mathematical argument instead of a human reviewer. Eleven days, largely on its own, 13 million lines, about 29,500 intermediate theorems along the way, and nothing assumed beyond Lean’s three standard axioms. Andrew Wiles’s 1995 proof ran 129 pages and took months of expert review to check.
I read that as a hardware story.
Eleven days of work, not a chat reply
The interesting part is not that a model knew number theory. It is that a machine did eleven days of sustained, structured work, and another machine checked every line of it. That is the shape of job we spec servers for now: long-running agents that read, write, test and retry against your own documents and code, not a question-and-answer box.
The frontier models live in their makers’ datacenters. What you can own is the open-weight class right behind them (Qwen, Llama, DeepSeek, Gemma), running on hardware you control, on your own documents, with no per-token bill and nothing leaving the building.
What that class of model does on a server you can buy
On our bench, a dual Intel Arc Pro B70 server runs Qwen3-14B at 54 tokens per second and Qwen3.6-27B at 26 (a token is about three quarters of a word), with the models resident in 64GB of GPU memory. The measurements, the software stack and the three power-management fixes it took to get there are in our benchmark write-up.
The money
Run the arithmetic our public rent-versus-own calculator uses (24 hours a day, 15 cents per kWh, $1,200 a year of overhead, a three-year payback) and an eRacks/AINSLEY at $21,395 pencils out against an AI bill of about $800 a month. A team of ten on $100 seats is $1,000 a month, forever. The calculator takes your own numbers, and every field is editable.
Every eRacks server is built to order, burned in, and benchmarked before it ships, with the numbers in the box. If you are sizing a machine for this kind of work, the AINSLEY configurator is the place to start, and a quote request gets a reply within one business day.
Joseph Wolff, Founder and CTO, eRacks Open Source Systems
joe September 9th, 2026
Posted In: AI Servers, News
Tags: AI server cost, eRacks/AINSLEY, Fermat's Last Theorem, formal verification, Intel Arc Pro B70, Lean, on-premise LLM, private AI, Qwen3
Hard Drive Prices Jumped 40 to 90 Percent Since March: Six Months of Our Own Tracking
A sale landed in our feed this week: thirty dollars off an 8TB Barracuda. Nice, if you need one drive. It is also completely the wrong number to be watching.
We price storage servers every week, so we track drive street prices daily and keep the results on a public page. The metric that matters is not the sticker on any one drive, it is dollars per terabyte, and over the last six months it has gone one direction.
What actually happened
These are the best prices we found in each month, not averages, so they are the floor rather than the typical ask:
| Drive line | Class | March 2026 | August 2026 | Change |
|---|---|---|---|---|
| Seagate Barracuda | Desktop | $16.25 | $31.25 | +92% |
| WD Red Pro | NAS | $24.84 | $41.22 | +66% |
| Seagate IronWolf Pro | NAS | $21.78 | $33.75 | +55% |
| WD Gold | Enterprise | $29.79 | $44.17 | +48% |
| Toshiba MG | Enterprise | $22.17 | $30.64 | +38% |
| Seagate Exos SATA | Enterprise | $24.33 | $27.92 | +15% |
The consumer line moved most, which is the tell. Desktop drives are the shock absorber of the storage market: they are the first to get discounted when supply is loose and the first to be repriced when it is tight. The enterprise lines with long supply contracts behind them moved least.
Why
The same squeeze that took DDR5 memory prices up this year is reaching spinning storage. AI datacenter buildouts are consuming manufacturing capacity and inventory across the board, and hard drives are being pulled into it as the cheap tier behind all those flash arrays. Meanwhile the drives most people actually buy, the 8TB to 16TB middle, are the ones the shortage bites hardest, because that is where consumer and datacenter demand overlap.
What this means if you are buying storage
Watch $/TB, not the discount. Thirty dollars off an 8TB drive that has already gone up sixty dollars per terabyte since spring is not a deal, it is a smaller increase. Divide the price by the capacity, every time, and compare that number to what the same class cost you last quarter.
The sweet spot moves. The cheapest terabyte is not always in the biggest drive, and in a shortage it moves around by the week. We publish the current best price per TB by capacity and by line, updated daily, at eracks.com/sweet-spots/drives, with the trend lines at the trends view. It is the same data we quote from, so you can check our arithmetic.
Buy the array you need now, not the one you will need in three years. The usual advice, buy extra capacity because it is cheap, assumes prices fall. They are not falling right now. Size the array for real growth, leave bays free, and add capacity when the market gives you a better number rather than paying today’s price for tomorrow’s data.
Fewer, larger drives still wins on the other costs. Even with prices up, a 24TB drive costs less per terabyte to power, cool, and rack than three 8TB drives, and it leaves bays open. The capacity ceiling keeps moving too: the largest drive in our catalog was 14TB in 2019, and it is 32TB today.
How we track it
A scraper walks the drive lines we actually build with, several times a day, records what each capacity costs from real listings, and computes price per terabyte. Every server quote we send is priced from that table on the day we send it, which is also why our quotes carry a refresh note: in a market moving this fast, a four-week-old number is fiction.
If you are sizing a storage server, a rackmount NAS, an all-flash array, or a media and video server, tell us the usable capacity you need and how fast it grows. We will size it against today’s numbers, show you the per-TB math, and tell you if waiting a quarter is the better move.
Common questions
Should I buy now or wait? Prices are not falling right now, so waiting is a bet, not a saving. Size the array for the growth you can actually forecast, leave bays free, and add capacity when the per-terabyte number improves.
Are enterprise drives worth the premium in a shortage? The gap narrowed: Toshiba MG enterprise at $30.64 per TB is now close to what a consumer Barracuda costs at $31.25, and the enterprise drive carries the longer warranty and the workload rating. When consumer pricing catches up to enterprise, buy enterprise.
Do these numbers include the drives in your servers? Yes. Every storage server we quote is priced from this same table on the day we quote it.
Scope note: our own daily tracking began in March 2026, so the chart is six months of first-hand data rather than a multi-year index. The capacity figures come from our catalog history.
joe September 3rd, 2026
Tags: component pricing, Exos, hard drive prices, NAS storage, price per TB, Seagate IronWolf, Storage Server, Toshiba MG, WD Gold, WD Red Pro, ZFS NAS