What is the coolest (Celsius) 4 GHz+ CPU with fan cooling?

Question

That includes stock and OC'ed performance.

Testimonials of fans and heat sinks would be great.

Answer 1

The only chips you are going to get up in the 4GHz range is a Pentium 4. They fastest chip ever officially released was a 3.8GHz Extreme Edition Pentium 4. (I say officially because Alienware did sell some PC's with the 3.8GHz processor clocked at 4 and 4.2 GHz)

The problem with relying on the GHz measurement is that it is not a true test of a chips overall speed. An AMD Athlon64 clocked at 2.4GHz could stomp the c**p out of a 3.8GHz Pentium 4 in any benchmark. In fact I don't know that AMD has released a Processor that runs any faster than 3.2GHz, but for a while their chips were WAY faster than even the top of the line offering from the Intel crowd.  It is all a matter of how efficiently it uses its CPU cycles.

The newer intel Core 2 Duo and Core 2 Quad lines are incredibly powerful. A chip at 1.6 GHz will routinely outperform the 3.8GHz P4 (less than half the clock speed.) It is all about performance per watt, and overall efficiency of Processor cycles. If you are just looking for a big overclock, get a high end Pentium 4 and the biggest baddes Thermaltake or Zalman cooling fan you can find. If you are looking for overall performance you would have better luck with the much newer Intel Core 2 or athlon Phenom line.  

Answer 2

I've been overclocking for years. I currently run an E8500 at 3.8 24/7 (9.5X400--1600FSB) and have it over 4 when benchmarking and thats doing easy clocking--haven't even seen how high it will go yet. Still breaking it in. I use a Thermaltake XP-120 with a 92mm Vantec Tornado that pushes 132 cfm of air when cranked up to over 4800rpm where it sounds like a hair dryer. A Zalman 9700 and some Arctic Silver 5 with an E8500 will put you in the 4Ghz club provided you use a good overclocking board like an Asus X48 and some hot ram like Corsair Dominator. Those are what I'm running it on. Temps run in the upper 40s when playing Crysis with the fan at about 3000rpm. Low 30s at stock 3.16 clock.. CPU runs really cool no matter how high I clock it. Nice since I don't have to deal with the hassle of running water. I have water stuff but dont need it on this cpu.