Hello, I'm looking to upgrade, from a stock q6600, and every dollar counts. So my question is how much difference in terms of performance am I missing if I choose a core i5 2500k over a i7 2600k? I'm also looking at asrock extreme3 z68 motherboard and 2x2x4gb ram. My video card is still suspect but I'm grabbing on the $100 range with the highest ram.

Here are the two cpu's specs:
Processor Number i7-2600K i5-2500K
# of Cores 4 4
# of Threads 8 4
Cache 8.0 MB 6.0 MB
Clock Speed 3.40 GHz 3.30 GHz
Max Turbo Frequency 3.80 GHz 3.70 GHz
Bus/Core Ratio 34 33
Intel® Hyper-
Threading Technology YES No

Thank you very much.

If price is a concern, go for the 2500K.

The 2600K has a modest clock increase, which you can match by simply bumping the multiplier up (as it's a K-series ‘unlocked’ processor), a bit more cache and can had 8 threads instead of 4. However, these only seem to give the 2600K a 10-20% lead over the 2500K, while the price is almost 50% more. If you do a lot of video encoding or rendering, the 2600K's price might justify itself, otherwise I'd stick with the 2500K.

Thanks for the quick reply, twod.

I'm looking to primarily work on Houdini effects. And by that, learn the process and mostly sim iterations. Maybe once i a while, I'll try to crank up the numbers of simulation quality or render HD but its not an everyday thing.

By your description, when I simulate something that would take 30 min in a 2500k, the 2600k could do it in about 20-25 min? I can live with 25% increase time. I apologize if I seem to ask your to repeat yourself.

Yes, money is a very big issue.

Yes, I will also try to overclock the cpu by maybe 25% in the first couple of months. It would be really bad to mess up the PC as soon as it hits the table. And, I have no experience in OC and I intend to use the motherboard's auto-overclock as a starting point.

I haven't done any tests with those two particular processors in Houdini, but similar workloads benchmarked by others lead me to believe you'd get, at best, 25% more performance from the 2600K. It really depends if that potential improvement is worth $100 to you. Depending on your graphics hardware choice, you may want to invest more into a more expensive card.

Usually overclocking requires more cooling, such as a larger case with more fans and a decent aftermarket cooler, which also add some non-trivial $$'s to the price. Also, if you don't have any experience overclocking a processor, I would suggest you forget that the “K” exists until you read up on it more and are comfortable in the BIOS of the motherboard. So, your plan of restraint sounds like a good one to me

I have same problem. I am on it Q6600 over 5year and its time for new PC.
so yesterday, I bought Core i7-3820, which costs slightly less money than 2600K, but Its slightly faster, you can still overclock(not much like a “K”) and mainly has “4-channel DDR3 memory controller”. But its LGA2011 which means that you need to spend extra $80-$100 for a motherboard
I will get the parts on Friday and Houdini will be so happy

thanks again, twod.

cybermax, are you going to let go of q6600? I'm going to use mine as a simulation pc or slave(?). Probably for rendering images so I can finally get familiar with rendering.

One last thing, am I making a wrong decision if I settle for a gt440 2gb dd3 with 2600k instead of gtx550 it 2gb ddr5 with 2500k? That's what my pocket allows. And, I decided not to overclock since I will keep the machine busy, hopefully. It also gets hot here during daytime.

I'm a little asky because this is kind of a one time rain of cash and it's going to take a while again. Thanks again!

Good luck with stuff!

One last thing, am I making a wrong decision if I settle for a gt440 2gb dd3 with 2600k

Nope, that would be the smart choice. It's far easier to upgrade a graphics card than a CPU. The PCI-Express slot will remain compatible for years, while CPU sockets change almost every year now.

I wen't with a GTX 550 Ti and a i7 2600K.

It was only about 40$ between the GTX 550 and then GT 440 so it seemed worth it to get GDDR5 memory instead of DDR3.