Probably MB not wired correctly

Eep386 wrote on 2018-05-19, 18:12:

The 90C33 is basically a 90C31 with a VLB / local-bus interface and support for up to 2 MB of memory. IIRC its acceleration engine is very similar to the 90C31's; about on par with a CL-GD5428/5429 performance wise. I'll agree with BSA Starfire about the 90C3x's generally very good DOS speed and compatibility.

Found some quite good and rare win311/95 2D benchmarks as wintach etc. on some Hungary site. The GD5428 was indeed much! better then the c31 in terms of GDI performance (ISA cards)