I just recently received an i7-2600k sandy bridge, to replace my i5-2400 but when I installed the new CPU my fps was lower than what I had with the 2400. With the i5 I had an average of about 10-20 fps taking off from Washington Dulles ( flight beam ) but with the i7 I had an average of about 2-6 fps

Also does it have to do with my CPU temp, I have the hp 644724-001 heatsink and fan and my CPU is normally at room temp when running fsx, plus my CPU never overheats.

Any tips to improve my fps?

I would over clock it. FSX is CPU intensive and your performance will go through the roof if you can get it to the High 4's

My i7-2600k sandy bridge  has been OC to 4.5ghz for years with no issues,using a NocturaNH-D14 cooler,it is easy to OC,if I remember correctly I upped the voltage and the multiplier,If you are not sure what you are doing though leave it alone and look it up on the webb you might find out more by doing a search on good old Avsim in the MOBO,RAM,CPU,S & OTHER HARDWARE FORUMS,I run P3dv2.4 at 30fps without much sweat

peter

 

You went from a 3.1 GHz CPU to a 3.4 GHz CPU, don't know why your fps would drop, that should have stayed the same, unless your motherboard driver and CIOS are not up to date and is not properly recognizing the new CPU.  Seeing as how it is an Hewlett-Packard computer, there may be an issue with the BIOS and motherboard driver when changing CPU's. 

In order to really improve FSX you will need to overclock the CPU.  FSX really needs all four cores running at 4 GHz or faster.

I forgot I have the weakest gpu I have the gt 520

But is my heatsink powerful enought to take my CPU to an OC of 4.2 ghz

I forgot I have the weakest gpu I have the gt 520

But is my heatsink powerful enought to take my CPU to an OC of 4.2 ghz

 

I would get water cooling. The lower the temps, the better for stability and longevity. It's cheap insurance.

I forgot I have the weakest gpu I have the gt 520

But is my heatsink powerful enought to take my CPU to an OC of 4.2 ghz

Your GPU is woefully inadequate for the 2600K i'm afraid. Regards

is the 660 ok for the 2600 plus I cannot OC my pc since I have a carmel2 motherboard and he option to oC is locked

is the 660 ok for the 2600 plus I cannot OC my pc since I have a carmel2 motherboard and he option to oC is locked

The 660 would be a good fit with the 2600. You have to take into account the rest of your system specs. If trying to upgrade an older off the shelf PC, you may not reap the performance gains you're hoping for. You're usually fairly limited in what you can and can't do in the way of a hardware upgrade in such a system. Regards

yeah cause I just ordered the 660 with an 600w PSU

The 660 will do fine I had that before i moved to a 770.