Blog

The Aulvem blog is where I keep the build logs of the things I make on my own, buying guides backed by calculations, and reviews of what I actually used. Three categories — Build, Guides and Reviews — under one theme: build it, write it down.

Guides

What Size Tablet for Reading? 8, 10 or 11 Inch

Calculated for tablets on Amazon.com, bunko paperbacks (Japanese novels) show at paper size or larger on 8-inch tablets and B6 manga on 10-11-inch ones, both borderline at the smallest size. A4 PDFs show at about 64-75% of paper size on the 10-11-inch class, and models from 12.9 inches up reach 80% or more.

Guides

Best Earbuds Mic for a Noisy Office: Look Past ANC

For calls in a noisy office, this guide picks the Bose QuietComfort Ultra Earbuds (2nd Gen), which Bose says reduces office chatter and wind on calls with AI. It lists 8 mics, but Bose doesn't say how many are for calls. This guide is based on the makers' official pages.

Guides

What Size Power Bank Do You Need for a 3-Day Trip?

On a 3-day trip at 60% efficiency, if you can charge at the hotel each night, a phone alone just barely gets by on 10,000mAh. A tablet or handheld console needs 20,000mAh, and a laptop 25,000mAh. With no outlet for 3 days and a phone alone, carry 20,000mAh and 10,000mAh banks.

Guides

What Monitor Does VALORANT Need? 144Hz vs 240Hz vs 360Hz

In this guide's method, pick a VALORANT monitor by your average in-match fps (frames the game draws per second). For refresh rate (how often the monitor redraws per second), 144Hz is enough at an average of 144 fps or less. Per Riot's official pages, the top spec target is 144 fps, and the in-game Stats display shows your fps. Checked against official pages and third-party data as of October 2026.

Build

My top country in GA4 was a bot — identifying Singapore traffic without ASN data

GA4 put Singapore at the top of my country report: 210 sessions in 28 days, one engaged, zero seconds of engagement. Cloudflare's free plan will not show the ASN, so I used what it does show — the screen size GA4 records and the Chrome version that fires the analytics beacon — and compared it with my readers in Japan.

Build

Blocking spoofed AI user agents did not clean my analytics — a month of numbers

I put two Cloudflare WAF rules in front of credential scanners impersonating AI crawlers. A month later the blocked requests were still in my analytics as 403s, the scan count had gone from 145 to 991, and the scanning had moved onto the names real crawlers use — ChatGPT-User and Amazonbot. What the numbers say and how I split the two jobs.

Build

AI crawler user agents are self-reported: 468 real fetches, 991 fake ones

Anyone can send a request calling itself GPTBot. Splitting eight days of Cloudflare logs by verifiedBotCategory and by whether the path exists in my sitemap left 468 genuine article fetches against 991 credential-scanning requests. The same UA string splits across verified and unverified rows, and one of the agents in my logs cannot exist at all.

Build

Is cross-posting duplicate content? I measured it before deleting anything

I was one command away from unpublishing five cross-posts to fix a suspected duplicate-content problem. Measuring the actual line overlap first killed the plan: 795 of 1,658 lines matched, but 762 of those were inside code fences and only 3 prose lines matched across 22 files. Here is the measurement and the canonical support matrix that replaced the deletion.

Build

A Google Sheets .xlsx breaks silently in Excel — rewriting 203 cells without dynamic arrays

Export a Google Sheet to .xlsx and ARRAYFORMULA / FILTER / SORTN / QUERY survive the trip, even though Excel has none of them. Worse, the IFERROR that was already wrapping them swallows the missing-function error, so the screen shows 'no matches' instead of #NAME?. Here's how I counted the broken cells with openpyxl and rewrote them as helper columns plus INDEX/MATCH so they run on Excel 2016.

Build

Idempotent notifications with an outbox — separate detection from sending, re-check right before send

Sending a notification the instant you detect the condition means stock or price can change between detection and delivery, and the alert goes stale. Instead, detection only enqueues into an outbox; a dispatcher re-fetches and re-checks right before sending, and drops anything that no longer holds. Here's the idempotent enqueue, the send-time re-check, and exponential-backoff retries as a state machine on Cloudflare D1.

Build

One Cloudflare Workers cron, many jobs — a per-minute tick with time branching

Cloudflare Workers' free plan caps cron triggers at five per account, which runs out fast once several services share it. Here's collapsing everything into a single per-minute cron that branches on UTC time to run patrol, send, and daily maintenance — and fitting each tick inside the 50-subrequest free-tier limit.

Build

Web Push without login — delivering notifications by anonymous device token

To send Web Push without accounts or email, you have to decide what holds the recipient before you send anything. Here is how an anonymous device token, minted into a cookie and delivered from Cloudflare Workers with VAPID over webcrypto, handles subscriptions, revocation, and the iOS and FCM gotchas that only surface on real devices.

Build

My top country in GA4 was a bot — identifying Singapore traffic without ASN data

Build

A Google Sheets .xlsx breaks silently in Excel — rewriting 203 cells without dynamic arrays

Build

Idempotent notifications with an outbox — separate detection from sending, re-check right before send

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Guides

What Size Tablet for Reading? 8, 10 or 11 Inch

Guides

Best Earbuds Mic for a Noisy Office: Look Past ANC

Guides

What Size Power Bank Do You Need for a 3-Day Trip?

Guides

What Monitor Does VALORANT Need? 144Hz vs 240Hz vs 360Hz

Guides

How to Choose a microSD Card: Markings by Use and a Bitrate Chart

Per Nintendo's US support page, the Nintendo Switch 2 only works with microSD cards built to the SD Express standard, up to 2 TB. In this calculation, recording at up to 240 Mbps is covered by a V30 card (at least 30 MB/s). Above 216 Mbps up to 240 Mbps the headroom is under 10%, so it's borderline. Worked out from the SD Association's and the makers' official pages as of October 2026.

Guides

Minecraft PC Requirements: RAM, GPU and What to Buy

Per Mojang's requirements table, Java Edition recommends 16 GB of RAM and a CPU such as a Core i5-12400. The GPU should have 6 GB of VRAM (its own memory), such as a GeForce RTX 2060. The minimum is 8 GB of RAM (12 GB with integrated graphics), 2 GB of VRAM and a CPU with 4 physical cores.

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Reviews

Manfrotto PIXI EVO review — a ball-head mini tripod that holds a full-frame body and still fits in a bag

Two-plus years with the Manfrotto PIXI EVO. A rated 2.5 kg load means it carries a full-frame body, and the low-to-high height range covers desk and eye-level scenes. At 270g it is on the heavy side, and the stiff ball-head lock makes 1° tweaks awkward.

Reviews

Sony Walkman NW-A105 review — the Type-C, Android DAP I switched to, revisited from 2026

Over five years of commuting with the Sony NW-A105. The USB Type-C, microSD, and Android wins weighed against the weak battery life and sluggish UI, with comparisons to the current NW-A300 line and to going phone-only.

Reviews

Peak Design Capture V3 and ProPad review — the clip that locks a DSLR onto your hip belt

A few years with the Peak Design Capture V3 (CC-BK-3) and ProPad (PP-2). The main draw is locking a DSLR onto a hip belt so you can raise it to your eye in one motion. The lock is solid and almost rattle-free, though tolerances against some plates can produce a metallic click.

Reviews

Sennheiser HD 598 SR review — open-back spaciousness and a fit that lasts for hours

A hands-on review of the Sennheiser HD 598 SR open-back headphones after years of work and personal use. Strong on soundstage and long-session comfort; weak on isolation and price tier. With closed-back and wireless comparisons.

Reviews

Elecom EX-G Bluetooth M-XGL10BBBK review — the budget mouse where grip differences show up most

A review of the Elecom EX-G M-XGL10BBBK, a low-priced Bluetooth mouse offered in three sizes. The grip punches above its price; wireless stability and the configuration software are where the corners were cut.

Reviews

Logitech MX MASTER 3 review — the natural sequel to the 2S, with USB Type-C and a MagSpeed wheel

A year-plus with the Logitech MX MASTER 3 at work and at home. Focused on the deltas from the 2S — USB Type-C charging, the MagSpeed wheel, and the redesigned thumb wheel.

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