I am looking to purchase a Precision T7920. How quiet are the CPU Fans in the T7920 on full load?

My T7910 fans starts to become noisy on full load but subsides after 20 mins while using the 90mm fan with water cooled heatsink.

I see the T7920 has it's own CPU cover with built in fan, does the heatsinks have fans built in like the T7910?

Is it much quieter with the CPU cover installed?

Thanks