New build_IS Heat OK?

This is my first effort to build a powerful gaming machine

Everything seems to be working ok except that cpu and mobo temp may be too high.

problem is I'm new at this so I don't know for sure if the temps are too high.

So I'll list my components and tell you some of the temp ranges I've registered and what i was doing at that time

Components...

AMD 64 X2 Athlon at 3.2 GHz (not overclocked) 125watt power requirement

Asus crosshair nForce 590 SLI

Rosewill RCX-Z1 cpu cooler (92mm fan/33-57 CFM)

2x gForce 9600GT

4GB Corsair RAM w/heat sinks

Silverstone 1200 watt PSU

1x WD 150Gb raptor HDD

2x WD 320Gb HDD

1x LG DVD/RW drive

onboard Soundmax audio

Xion case (120mm front intake fan/120mm rear exhaust fan/90mm side exhaust fan

The case is big, so even with all that stuff in it it's open inside, nothing is cluttered and has ample room to move air around

These readings were taken at night...not sure what ambient room temp was but it was cool.

CPU/Mobo temp...

just started Bios says 40/28
this quickly goes to 50/32
system idles at 53/33

booted up I use PC Probe II and CoreTemp to monitor cpu temp
they indicate idle temp at 47-50

slightest activity will push this to 55-57

playing F.E.A.R. on high settings for about 45mins pushes cpu temp to 75

Is this too high, do I need to take steps to cool the cpu?

I tried a few cpu coolers, including this massive job that blew air back towards the exhaust vent, but the Rosewill one seems to work best

Is this too high, do I need to take steps to cool the cpu?

I'm not getting any warnings but 75 celsius seems too high to me.

cpu pefromance takes a noticeble drop as temps increase

70-75c is high

65c is better as a top end temp after equilbrium is reached, endless ramping temps is bad!

65-70c is the max i use for the hottest chips at high oc, thats after days of running and stable temps are reached. systems that ramp up and up are trouble waiting

i.e. quad at 3.6-4ghz on air

chipsets run hot when the fsb is raised higher then standard, nvidia run hotter then intel for most part, newer chipsets tend to run cooler

60c is normal for a mobo and safe

the chip is silicon which melts a 1700c the wire is copper that melts over 1000c - but you can damage resine or plastic thats sometimes used at 85c