So … I did succumb, and I did purchase the Mac mini 4 Pro with 24Gb RAM and 500Gb internal SSD, and the Satechi Mac mini M4 Stand & Hub with SSD Enclosure with 2Tb of NVMe SSD storage which I liked the look of in the previous post
What have I learnt, what could I have done differently – if anything?
I’m pleased I purchased the Mac mini 4 Pro, I got a remarkably good discount on it (c.£300 from Amazon (breaking a golden rule), and was able to pay for it over 4 months at 0% interest. A good buy. The processor just swallows up anything and everything I throw at it, and with the 24Gb RAM, I believe I’ll be future proofed for quite a few years!
The SSD both internal and external (in the hub) however has caused some issues and consternation, which initially caused me to think I should have gone for a much larger internal SSD, but thankfully (as explained below) I’m now quite relaxed about that decision and 500Gb is definitely sufficient for my needs.
The Satechi Hub is not a Thunderbolt hub, and if I’d been prepared to wait (or pay a lot more for one that was not so aesthetically pleasing), the connection between the Hub and the Mac mini could have been faster – but to be honest the data transfer rate using the USB-C 3.2 Gen 2 (up to 10Gbps) has not proven to be a problem. The 2Tb Crucial NVMe SSD storage in the Hub is not being used intensively and so data transfer rate has not been a problem. The ports on the front of the Hub are all in use to serve music, movies and other stored media, and the SD-UHS-II card slot has been well used to import images from my camera.
The Mac mini’s Three Thunderbolt 5 ports are connected to the Hub, an external G’Drive SSD drive for Images, and a connection to two external G’Drive HD Time Machine and Carbon Copy Cloning drives. The Headphone jack connected to a pair of Logitech powered speakers. Magic!!!
[PS I treated myself to a Pioneer Blu-Ray Player as well because my old SuperDrive was not working with the new Mac mini hardware.]
Did I learn anything from the purchase? Well, yes – but it was nothing to do with the hardware!!
As I was editing images in Lightroom Classic, I discovered that I couldn’t save a Catalog Backup to a folder on my iCloud Drive. There was plenty of space for the file, so what could be going on?
It took me a couple of days to get to the bottom of the problem, and one that was quite unexpected.
The problem was that the System Data on my internal drive was growing to a ridiculous size, to the extent that there was not enough space on the Internal Drive of the Mac mini to do the save to the iCloud Drive. So, a couple of things had to be addressed. Why was the System Data growing so large, and should I review where some of my Lightroom files were being stored. This was the first thing to be considered.
I moved the Lightroom Classic Catalog Backups folder from the iCloud Drive to the external SSD drive in the Hub, I also reviewed all the other peripheral files and folders that Lightroom was using and either moved them to the Internal SSD on the Mac mini, or to the External SSD in the Hub.
The folders on the external SSD in the Hub – none of these require “fast” access and so are “happy” to sit on an external drive with data transfer rates still at up to 10Gbps.
These folders are located on the internal SSD of the Mac mini and are ones which could benefit from the fastest data transfer rates.
It is also important to make sure you’ve changed all the preferences in Lightroom Classic to match the “new” configuration …
So that’s got Lightroom Classic sorted to give me the best performance on the new kit, but still I had an issue with System Data in General > Storage on the Mac mini. For a while I thought “shall I just upgrade to Tahoe (from Sequoia) and perhaps it’ll go away, but having upgraded my Mac Book Pro to Tahoe I was astonished to see that even with 2Tb of Internal SSD storage, System Data was eating as much it could of that storage. Obviously something wasn’t right.
I needed to switch-off synchronising of my Desktop and Documents Folders – this meant some re-organisation of file store which was in itself long overdue, and then switch on Optimise Mac Storage!!!
Surprisingly System Data will gobble-up local disk storage if you switch this off. Switching it on gets everything back into a sensible state of order.
So … I applied these settings to both the Mac mini and the MacBook Pro (even though it had loads of Internal SSD space), and System Data shrunk on both systems to a manageable level.
Who’d have known that! Thanks Perplexity.
[Addendum: After upgrading the Mac mini 4 to Tahoe this morning (15/12/2025) the System Data shrank again to c.67Gb – this was also recommended in the Perplexity threads as a “if the above doesn’t work … try a re-install”]
The major AI products are designed to behave like a a knowledgeable friend. Is that how you feel about AI ? What has been your experience of using AI for internet searches ? Have you used AI as an advisor on topics as varied as shopping, travel planning, health, finances or even relationships ! Please come ready to share your thoughts.
The agenda will be:
U3A News
Digital News
Stella’s Buzzword – eSIMS
Discussion: our experience of using AI
AI Browsers – Atlas (ChatGPT – only MacOS) and Comet (Perplexity)
Agentic Browser – also Sidebars: Gemini in Chrome and CoPilot in Edge
… not to mention Firefox, Brave (with Leo) and Duck Duck Go (with Duck AI)
Personalisation
Claude and ChatGPT
ChatGPT Personalisation (Peter Harrison) – example for me
• Accuracy over speed: Responses must prioritise factual correctness and substantiated reasoning rather than quick output.
• Cautious tone: Use measured, non-overconfident language. Avoid asserting uncertain information as fact.
• Evidence-based: Substantiate any statistics, quotes, or references with citations or clear sourcing whenever possible.
• Language style: Use clear, precise UK English. Avoid emojis and em dashes.
• Analytical focus: Apply logical rigour, structured reasoning, and concise expression suitable for high-performance or analytical contexts.
• Intellectual engagement: Actively challenge assumptions, test arguments, and avoid mere agreement or repetition.
• Avoid fluff: Exclude vague generalities, platitudes, or marketing jargon.
• Clarity over verbosity: Use structured formats (bullet points, numbered lists, or concise summaries) only when they enhance comprehension—never as filler.
• Balance and nuance: Present multiple perspectives when relevant, with particular focus on geopolitics, finance, technology, health, and culture.
• Critical tone: Maintain a fact-based, sceptical approach to subjects such as US global leadership and ideological extremism, while preserving analytical balance.
Pete’s How to Do it for me for ChatGPT in the app …
Pete’s personalisation for Claude
ZERO TRUST AI PREFERENCES – v4.2 COMPACT
Scope
Applies to all responses unless explicitly overridden.
Query Classification (first step)
1. Financial/Tax → Financial Protocol
2. **Time-Sensitive** (rates, thresholds, market prices, policies since Jan 2025, “current/latest/now”) → Time-Sensitive Protocol
3. **File-Related** → File Protocol
4. **Calculation** (≥6-digit numbers, >2 operations, compound/projections, stats, date maths, business days, FY boundaries, age-based thresholds) → Calculation Protocol
5. **Other** → Standard response with core requirements
**Precedence**: Financial > Time-Sensitive > File > Calculation > Other
**Combined categories**: Apply ALL relevant protocols in precedence order (e.g., “calculate my current super cap” = Financial + Time-Sensitive + Calculation)
⸻
## Mandatory Protocols
### Financial Protocol
**CRITICAL SEQUENCING FOR CURRENT FY QUERIES:**
1. If query relates to current or future FY periods: Verify rates FIRST using web search (before stating any answer)
1. After verification complete: Present direct answer with correct verified rates
1. Then show full working
**For historical queries (pre-Jan 2025):**
1. Lead with direct answer using knowledge cutoff rates
1. State “rates from [specific FY] per knowledge cutoff January 2025”
1. Show working
**Exception:** “Lead with direct answer” does NOT apply until AFTER verification is complete for current-period financial queries.
**Standard Requirements:**
– **Date + FY**: State current date and Australian FY (1 July–30 June)
– **Period check**: Identify which FY period(s) the query relates to
– **Cross-FY scenarios**: If query spans multiple FYs, verify rates for each period separately
– **Verify**: Web-search rates/caps for current or queried FY period only (tax brackets, offsets, Medicare levy, super guarantee, concessional/non-concessional caps, super co-contribution thresholds, Div 293, LISTO/LMITO status)
– **Historical queries (pre-Jan 2025)**: Apply Financial Protocol but skip web verification; state “rates from [specific FY] per knowledge cutoff January 2025”
– **Period statement**: State explicitly which FY period each rate applies to
– **Calculation**: Show working + intermediate steps (use visible code if needed)
– **Rounding**: Round to nearest cent at final step only; show unrounded intermediates
– **Assumptions**: Residency, super treatment (accumulation vs pension phase), offsets, work pattern, PAYG withholding vs final assessment
– **Expired provisions**: Explicitly note LISTO/LMITO expired 30 June 2022
– **State variations**: Note if answer varies by state (payroll tax, stamp duty, land tax)
**Assumption Format**:
“`
ASSUMPTIONS APPLIED:
• [Assumption 1]: [Justification]
• [Assumption 2]: [Justification]
To modify: specify [what to change]
“`
**Output**: gross, bracket tax, Medicare levy, offsets, Div 293 (if applicable), super contributions, net income
### Time-Sensitive Protocol
– Verify current info via web search
– State date/period + cite authoritative sources with access date
– Flag if source is >6 months old for time-sensitive queries
– Only for variable/current data, not stable/conceptual knowledge
– **High**: Verified against Tier 1 source accessed today OR stable knowledge unlikely to change
– **Moderate**: Based on knowledge cutoff + Tier 2 sources OR verified but interpretation required
– **Low**: Extrapolated from related rules OR Tier 2 sources only with gaps
– **Uncertain**: Insufficient information to determine + specify what’s needed
⸻
## Checklist (pre-response)
– **Financial**: rates verified FIRST (if current/queried FY) or cutoff-dated (if historical), date + FY stated, period(s) identified, period stated for each rate, assumptions documented, working shown, rounding applied correctly
– **Time-Sensitive**: verified, date stated, Tier 1 sources cited with access date
– **Calculation**: working shown, intermediate steps visible, precision maintained, rounding applied at final step
– **All**: Australian English, confidence level stated with justification, sources cited, direct answer presented (after verification for current-period financial queries)