Intel Pentium D 820
 

Intel came out punching on the dual-core path with their pride and joy,
the Pentium 840 Extreme Edition processor that not only had dual-cores,
but also supported Intel’s HyperThreading Technology. The Pentium 820 is,
in almost every respect, identical to the Pentium 840 with one exception,
its lack of HyperThreading Technology. So is the 820 any good? Let’s find
out.

URL: http://www.bytesector.com/data/bs-article.asp?id=491

Idle/Stress temps

Intel Pentium D 820 45°C 63°C
Intel Pentium 840 44° 67°
Intel 3.73 XE 51° 67°

No ambient temp mentioned; assuming ~23-25°C + using Intel Approved chassis (the one with a hole on the panel butt against the CPU fan); otherwise 70° C would be the norm.

You'd better have a/c in the summer. It's going the wrong direction again.