Client Reports & Testimonials
Feedback and case summaries from South Korean mining operators who used System Cypresshub assessments before procurement or fleet expansion.
What Clients Say
The comparison report on our two Antminer S19 variants saved us from ordering twelve units that would have landed in Class D. The watt-per-TH figures matched what we saw after a week of operation, though I wish the thermal section had covered our specific rack airflow setup.— Min-jun Park, 1.2 PH/s facility, Hwaseong
We brought Cypresshub in before a second-hand lot purchase. They caught a batch with degraded hash boards that the seller's spec sheet did not mention. Straightforward process, no sales pitch for hardware we did not ask about.— Soo-yeon Han, independent miner, Suwon
The fleet session identified three units running outdated firmware that had drifted two efficiency classes below their rated tier. Dong-wook was thorough on-site, though scheduling around our production window took an extra week of coordination.— Young-seok Choi, operations lead, 3.4 PH/s warehouse, Ansan
I used the pre-acquisition audit for a lot of six Whatsminers from a distributor in Incheon. Four passed cleanly; two were borderline Class C when the seller claimed Class B. The report gave me leverage to renegotiate, which alone covered the audit fee.— Eun-ji Ryu, procurement, mid-size operator, Incheon
Case Summary: Hwaseong Facility Comparison
Client: Min-jun Park, operating a 1.2 PH/s facility in converted warehouse space.
Challenge: Choosing between Antminer S19 Pro and S19j Pro for a 0.6 PH/s expansion. Manufacturer datasheets showed similar efficiency, but local operators reported different results on Korean power.
Engagement: Efficiency Class Comparison Report covering both models over a 72-hour bench run at 22–26°C ambient.
Outcome: S19j Pro assigned Class B (27.5 J/TH measured); S19 Pro assigned Class C (31.2 J/TH measured). Client ordered S19j Pro units and reported actual operating efficiency within 3% of our projection after 30 days.
Reservation noted: Client requested rack-specific thermal modelling, which falls outside the standard comparison scope. We referred him to a cooling consultant for airflow simulation.
Case Summary: Ansan Fleet Drift
Client: Young-seok Choi, 3.4 PH/s deployment across four racks.
Challenge: Electricity costs rose 18% quarter-over-quarter without a matching hash-rate increase. Internal checks showed uneven per-unit output.
Engagement: Two-day Fleet Benchmark Session testing 42 units.
Outcome: Three units with degraded hash boards flagged for retirement; eight units running outdated firmware identified and updated; two racks repositioned to improve intake airflow. Post-session efficiency improved to within 5% of original commissioning benchmarks.
Case Summary: Incheon Second-Hand Lot
Client: Eun-ji Ryu, evaluating six used Whatsminer M30S units.
Challenge: Seller claimed Class B efficiency on all units. No independent verification available.
Engagement: Pre-Acquisition Rig Audit with physical inspection and 48-hour bench run on all six units.
Outcome: Four units confirmed Class B. Two units measured Class C due to fan wear and one partially failed hash board. Client renegotiated price downward and retired the two underperforming units rather than deploying them.