About Portalcypressway

Registered business

Portalcypressway Mining Review Co., Ltd. is the official registered name under which we operate. We were established in 2019 in Incheon’s Seo-gu district, beginning as a two-person bench lab focused on SHA-256 ASIC verification for local hosting clients.

Brief history

In 2019, co-founders Ji-hoon Yoon and Eun-kyung Han opened a small testing room near Demo-ro after repeatedly seeing imported miners arrive with hash deficits that sellers blamed on “pool variance.” They built a repeatable 48-hour burn-in protocol and started issuing plain-language reports operators could hand to landlords and insurers.

By 2021, demand from Gyeonggi warehouse operators led us to add on-site audit visits. We deliberately stayed BTC-only — our clients wanted clarity on Bitcoin block reward economics, not firmware that switched coins overnight.

Today we maintain a lab bench for units from 0.05 PH/s to multi-petahash containers, plus a reference library of firmware versions seen in the Korean grey and official import channels.

What we do

We review mining hardware the way a mechanic inspects an engine: measure output, listen for failure modes, document what we see. We are not a pool, not a broker, and not a hosting provider. Our revenue comes from assessment fees and advisory sessions.

Working approach

• Measure before opinion — Numbers from clamp meters and pool dashboards, not brochure specs.
• BTC-only scope — We decline dual-mining evaluations to keep reports comparable.
• Plain language — Reports readable by non-engineer facility owners.
• Disclosed limits — If we cannot access a rack or roof line, we say so in writing.

Team

Ji-hoon Yoon — Lead bench technician. Former industrial HVAC installer; handles thermal mapping and airflow remediation advice.

Eun-kyung Han — Operations and sourcing research. Tracks import documentation requirements and vendor shipment patterns.

Sora Kim — Client intake and report editing. Schedules lab slots and coordinates on-site visits across Incheon and Gyeonggi.

Values

Accuracy over speed. We occasionally turn down rush jobs when lab capacity would compromise burn-in duration. We treat client serial numbers and facility locations as confidential unless you authorize disclosure in a case study.

Community

We sponsor an informal monthly meetup for small-scale operators near Incheon Station — attendance is free, no sales pitches. Ask us for the next date when you get in touch.