My CPU Pentium D 945 rev D0 is 95Watt, hope Aluminum heat sink is enough.
CPU makes frequency switching from 2.4GHZ till 3.4GHz, it means without load power consumption can be even less 95Watt.
Also Cooler in idle state run 750rpm without any noise. Only for stress test for 15min it run on 1500-1900rpm
Unfortunately can't measure CPU temperature (BIOS or AIDA64 software...etc)
I've upgraded the former P4 to a PD 945, the stock cooler works, but the fan goes crazy in high cpu loads, I wouldn't stay more than a couple of minutes in this state.
Upgrading to the copper heatsink, or checking if that's possible to use a regular cooler system seem to be the best bets.
The copper heatsinks are not hard to find and they are not expensive. I get them all the time on amazon and ebay. The 130w versions of the cpu are what the heat issues come from.
I answer to my own post just to say that with some thermal paste, no crazy fan anymore, in fact, it's quite quiet now, even while playing Minecraft or installing stuff, which would have made it crazy in the first place.
So, now here's what's in my Dell Optiplex G620 :
Pentium D 945 CPU, with stock cooling system (just cleaned and added thermal paste).
4 GB or RAM, which is the max possible, unfortunately, only 3,5Gb are usable, I think the BIOS saves 512Mo for its own use, and there's no way to change this, but that's still fine.
A Nvidia GT 610 graphic card with 2Gb of memory, passive cooling, and very small size, in the first place, I bought a Nvidia 8800 GTS with 512Mb, which is much more powerful for gaming, but it didn't fit in the case, so I put it in my mother's PC and I took her GT 610 instead, which is more than enough for working, multimedia purposes, and even some gaming, Minecraft runs well.
The OS is Manjaro Linux, which is quite light, responsive, user-friendly and with a good following, just forget about Windows on such PCs, Linux does better, with less ressources, and it's way safer, as it's always updated, unlike Windows XP, which has no support anymore. In fact, my only PC which still has Windows (10) is my gaming PC, because I have no choice, but unless you're a PC gamer, or working with software that doesn't exist or has no replacement on Linux, I just see no good reason to stick to Windows.
So, I'm quite happy with this PC, it does better that I've thought, someone gave it to me for a 40€ debt, and for just a few more bucks, I turn an almost useless PC to a solid working/multimedia PC, good deal 🙂