Many-PCIe motherboards. List of motherboards with 8+ PCIe slots, sometimes in the form of a mechanical USB port carrying an electrical PCIe signal. Some motherboards with less than 8 slots may be listed, but they are clearly designed for GPU cryptocurrency mining, password brute forcing, etc; for example they have plenty of double-spaced ×16 slots. List curated by mrb.

Asus H370 Mining Master 20 [archive]
Asus B250 Mining Expert 19 [archive]
Esonic Q270-BTC-GLADIATOR 15 [archive]
Asrock H110 Pro BTC+ 13 [archive]
MSI H310-F PRO 13 [archive]
OEM ZA-B250-D12P 12 [archive]
Colorful C.B250A-BTC V20 12 [archive]
Gigabyte GA-B250-FinTech 12 [archive]
Biostar TB250-BTC PRO 12 [archive]
Esonic B250-BTC-GLADIATOR 12 [archive]
OEM B250 12P 12 [archive]
Supermicro X11DPX-T 11 [archive]
Supermicro X10DRX 11 [archive]
Supermicro X9DRX+-F 11 [archive]
Sunfa 6299-FA355 9 [archive]
Shenzhen Zrt ZRTK-21613 & ZRTD-101 9 [archive]
RebTech 8GPU-MB 8 [archive]
Shenzhen Zrt ZRTK-21612 8 [archive]
Colorful C.J1900A-BTC PLUS V20 8 [archive]
Colorful C.B250A-BTC PLUS V20 8 [archive]
Colorful C.A68M-BTC V14 8 [archive]
Octominer B8PLUS 8 [archive]
Onda B250 D8P 8 [archive]
Yanyu Gongkong K37 8 [archive]
Yanyu Gongkong K35 8 [archive]
Yanyu Gongkong K17 v1.2 8 [archive]
Yanyu Gongkong K17 v1.0 8 [archive]
Letine M08 8 [archive]
OEM Olike3C 8 [archive]
Biostar TB250-BTC D+ 8 [archive]
Biostar TB250-BTC+ 8 [archive]
Onda D1800 BTC 6 [archive]

Last updated in June 2018.