Overclocking, voltage, heat and i7 vs Core 2 Quad?

[aamsel]

I have read a ton of threads that involve the overclocking
"fun" that many are having with the i7's.

I have posted before that I am a single-GPU user, non-gamer,
currently using an E8600 @ 4.1GHz, just over stock voltage, and
cooled by a hampster running slowly on a wheel, taking occasional breaks! <grin>

OK, slight exaggeration, but this thing runs very cool.

I have sufficient needs to justify a quad upgrade, but have gone back and forth
between a total new i7 platform (920 or 860) and a Core 2 Quad Q9550.

If I am looking at temps that are in a similar range o/c to 4GHz (or below) with either a Q9550 or either i7 chip, then the money difference in getting a new motherboard and memory for the i7 would not deter me from making the jump to i7. If there are far more manageable heat levels with the C2Q then that would be a a big plus.

Is an overclocked Q9550 likely to run far below the temperature range of an i7?
Fully realizing that any chip in itself is unique, what would the likely temperature at
full load be of a Q9550 overclocked to its non-pushed maximum speed?

Also, I have read that the Q9550 E0's are generally refined to the point that they
can run on quite low voltage, true?

 

[cmdrdredd]

The issue people have with i7's at 4Ghz+ and the temps running up is the fact that they need a big jump in voltage to get there. Plus with HT on the CPU is doing extra work and heats up a lot more. Turn off Hyper Threading and you will see about 5-10c temp drops at full load at the same clock frequency.

my Q9550 runs 40-43c at idle and load is about 66-67c at 3.8Ghz with voltage around 1.34v after vdroop. I have a C1 stepping

 

[aamsel]

The issue people have with i7's at 4Ghz+ and the temps running up is the fact that they need a big jump in voltage to get there. Plus with HT on the CPU is doing extra work and heats up a lot more. Turn off Hyper Threading and you will see about 5-10c temp drops at full load at the same clock frequency.

my Q9550 runs 40-43c at idle and load is about 66-67c at 3.8Ghz with voltage around 1.34v after vdroop. I have a C1 stepping

So, overall, the Q9550 would still be a cooler running chip, especially
with an E0 stepping?

And, compared to an overclocked i7, is the Q9550 maybe a 15-20% drop
in performance compared to the i7 overclocked? (obviously there are some
tasks that would be an even higher percentage, I realize that).

 

[cmdrdredd]

So, overall, the Q9550 would still be a cooler running chip, especially
with an E0 stepping?

And, compared to an overclocked i7, is the Q9550 maybe a 15-20% drop
in performance compared to the i7 overclocked? (obviously there are some
tasks that would be an even higher percentage, I realize that).

That depends on whether you're running turbo on and have a boost in single and dual thread apps, or have HT on for apps that use multiple threads. That's where the i7 shines.

Take a look at the graphs in the review here http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3634&p=13

You see that the i7 920 is at 2.66Ghz (stock frequency) and the Q9650 is at 3.0Ghz (stock frequency). The Q9650 loses to the i7 every time. Even for gaming the i7 gives better results. There's many times the i5 750 is beating the Q9650 when the i5 has no hyper threading.

I would say the Q9550 is going to run cooler, but you could always turn off HT on the i7 or get an i5 and get it to 4Ghz and have a system that is overall faster than a LGA775 system at the same frequency. Remember the PCIe and memory controller is on the CPU with the LGA1156 CPUs. That's low latency and better overall performance than LGA775 can hope for.

It depends what you're doing and if you want to spend the money to build new.

 

[aamsel]

Thanks.
Loooks like I will go new.

Now, just to decide 860 vs 920 one more time.