Yes your RAM should be fine up to 1066. Most DDR2 1066 was just factory overclocked DDR2 800 so don't expect much beyond 1066 as the RAM is already overclocked. Just make sure to set it at the correct voltage. Probably 2.1v if I remember DDR2 correctly.
Yep. And assuming it's quality RAM it's probably good a bit past that just not a huge amount. Like it might go to 550/1100 if your lucky. Only way to tell for sure is to try since just like with a CPU no 2 RAM kits will be identical in overclocking performance.
Like I said keep going until you hit a wall somewhere. I had 4GB of Corsair DDR2 800 paired with an E8400 that was overclocked to 4Ghz for 2 years. At 450 FSB that means the RAM was at 900Mhz. I hit the processor's limit way before the RAM limit.
Mine was on a Gigabyte EP45 UD3 motherboard with a ZeroTherm Nirvana NV 120 CPU cooler. Great chip in it's day. Idled in the low 30s C and hit the low to mid 60s C under Prime 95 load. Rock solid overclock for over 4 years now. I sold it to a friend when I upgraded and it's still running.
With a good board ( P45 was the best LGA 775 overclocker ) and good cooling you should hit 4GHz easily. 3.6Ghz was easy with no voltage boost. Just set the FSB to 400 and it was good.
Overclocked it fine to 3.6 Ghz and it runs stable. Average temp of around 52 - 55 C while being stress tested. Planetside 2 works a treat now, probably allowing my GTX 580 to actually work.
Cant get it to run stable at 4.0 Ghz, windows starts fine and everything works until i run Orthos and stress test. The test stops almost instantly although it doesnt register any errors. Tried to increase the voltage but same error after 2 further increments. Any help on why?
Also, while stress testing the RAM according to windows CPU meter only goes to 74% while the CPU is at 100%, is this due to the fact that windows 7 CPU meter is rubbish or another problem or it should be doing this?
Those temps are great. What motherboard do you have? Some boards have a FSB wall that they will not go beyond. As I said above the P45 boards were the best overclockers in my experience. And every chip is different, yours just may not like 450 FSB. You can try like 440 or 452 ect., just play around with it as it might be that exact number it does not like.
I like Prime 95 and Intel Burn test over Orthos myself. Coretemp and HWMonitor to measure temps. Use the Small FFT test to make sure the CPU is stable and the Blend test for CPU/RAM in Prime 95. It should pass an overnight run of 8 to 10 hours to be sure it's stable.
You are just using that Windows gadget to measure the RAM? I would not put much stock in it myself.