The defined answer is, if you use a single stage hydraulic pump, it will be slow. A 7 HP engine running at 360o rpm, can run a .2 cu in pump, and produce 3.2 GPM. Using a 4 in cyl. Cycle will be 55.2 sec. Force applied will be about 18.5 ton
A two stage hydraulic pump will provide more GPM's because the first stage is pumping fluid at a lower pressure about 650 psi, and more GPM, At a set psi point, the pump will automatically shift to high pressure, 2500 psi and low GPM,s. Pressure determines power, and GPM determines speed of cyl operation.
The 13 GPM 2 stage pump, using the 6.5 HP engine. Force applied, 15 ton.
The cycle time of a two stage pump will vary based on the time the pump stays in the fast mode. If you are splitting very hard or stringy wood, the cycle time will slow down .