Possible waterflow problem

Hi all, I'm currently flushing my system, and it's really the first time I've noticed how much water my pump is pushing out.

IMHO, it's not nearly as much as it should be.

I have a Swiftech MCP-655 Pump
Thermochill 120.3 radiator
Swiftech STORM CPU Block (R2)

everything is 1/2" ID

Now the pump is rated at max 317 GPH, or 5.2 GPM. Now if i have my pump set to the "1" setting, I'm hardly moving any water at all, like my tubes won't even completely fill. If i run my pump at "5" it will fill all my tubes and stuff, but the rate of flow coming out is hardly 5 GPM, I'd say maybe not even 1 GPM. The water is flowing out, just not very much as I would prefer or hope for such a hich performance pump.

Now is this normal? Or does it look like i have something blocking my flow? i just replaced all my tubes and everything. I made sure to bleed my radiator.... I just want to make sure this is normal before i actually put my solution in and close the loop.

If i had to say 1 component that was limiting water flow the most, it would be the cpu block. I believe that if i set the pump at "1" and turn it on, most everything looks good until the water hits the CPU block. Is there anything i can do to increase the flow to it?

thanks for your help.

I'm cooling duel 8800 GTX's, after the CPU

Res> Pump> radiator> CPU> GPU> GPU> Res.

I really don't think that my rad. is the flow rate restrictor.... I accidentally forgot to put my radiator bleed cap on when i started the final flush with distilled water. Turned the PSU on, noticed some weird sounds, and water shot out of my radiator and hit the ceiling.

And here's a picture of the flow rate at the end of the loop: