How to parallel executing a command using subprocess?

[larkypython]

./PoreDy is the command I want to execute, and jobname and 1001 is the argument it required.
My code is as follows:

TotalThread=24
CheckInterval=2
for i in range(CasesCount):
		jobname=Name(FolderName+'_', i)
		cmd='cp -f'+SettingMatch+' '+jobname
		subprocess.call(cmd, shell=True) # Pay Attention
		print('executed ', cmd)

		cmd='./PoreDy '+jobname+' 1001'
		job=subprocess.Popen(cmd, shell=True) # Pay Attention
		Runs.append(int(job.pid)+1)
		print('executing ', cmd, ' Job ID: ', int(job.pid)+1)
		print(Runs)
		time.sleep(1)

		while len(Runs)>=TotalThread:
			for run in Runs:
				if Running(run)==False:
					print('PID ', run, ' Finished!')
					Runs.remove(run)
			time.sleep(CheckInterval)

I got two problems:
1: the command has many outputs, I don't want to see its stdout which usually shows on screen when I manually run it.
2: looks this code doesn't fully use my all threads, actually only 4 or 5 of them are used simultaneously.

Please help out, this stuck me for a long time.