Im going to be building a dedicated pc for use as the main source in my high end audio system, it will also need to be able to play/record video as well. My current system just didnt cut it for use in my audio system as it was far to loud. So my main question is what cpus are good for use in quiet HTPC system, re thier any modern dual cores that can be passively cooled?? The most interesting cpu to m righ now looks like the AM be2350. Any other ideas/advice?
thanks

Passive cooling depends on the heatsink you plan to use. With something like a Ninja, every C2D dual-core model can be passively cooled.

You certainly want a low-TDP chip. There are a few options for you, and I'll rank them.

1. AMD Athlon X2 BE series (45 watt.) There are quite a few good mini-ATX and even a couple of even smaller mini-ITX boards for AMD AM2 socket CPUs. This will be the best performance for the dollar setup by quite a bit and would be my recommendation for a best bang-for-the-buck system.

2. Intel Celeron D 400 series (35 watt.) These are single-core Core 2 Duos with 512 KB cache. They are a little less expensive than the X2 BE series but the motherboards will be more expensive for the same features. All in all, the Celeron D will be a little cheaper and run a little cooler at full roar than the X2 BE will, but at a significant performance deficit.

3. AMD Athlon 64 "Lima" (45 watt.) This is the 65 nm incarnation of the single-core Orleans AM2 Athlon 64. Quite inexpensive and a better buy than the Celeron D 400 series, but they can get a little warmer at full load and aren't that much less expensive (but much less powerful) than the X2 BE series.

4. Turion 64 MT (25 watt.) Many people put one of these chips on a Socket 754 motherboard to make a very efficient mobile-on-desktop (MoD) setup, but the Turion 64 MTs went out of production a little while ago and thus are more expensive than the desktop chips above. Socket 754 is also dead and a good 754 motherboard can be a bit tricky to find as well. If you do your homework and are able to locate good parts, this could be a contender.

5. Core 2 Duo T series (34-35 watt) in a Socket M or P MoD setup. The T7200/7300 and higher are faster than any of the other options at a mid-range heat dissipation, but they are MUCH more expensive than the desktop chips. The motherboards are also rare and very expensive as well. I'd not go this route unless you need that much power and cannot stand to use a 65-watt desktop chip like the Core 2 Duo E series or Athlon 64 X2 EE Windsor or Brisbane chips.

Just make sure you have good ventilation and a good heatsink.

MU_Engineer does provide you with some options regarding CPUs with low TDPs. However, I intend to put my E6600 into a HTPC when I upgrade to a Penryn CPU.

At stock speed, the E6600 only consumes 52w under 100% load. The Scythe Ninja should have no problems passively cooling the E6600. People have been using the Ninja to passively cool the older S939 Athlon X2 4200+ with no problems (S939 X2 3800+ consumes 65w under full load).

Thanks for all the good info guys. Ill probably go with one of the less expensive less powerful cpus. I really dont need much cpu power since this system will be mainly for playing back audio files.

Hmm, then that sounds like a candidate for one of the low-power, low-priced CPU/mobo combos that Newegg often has. Here are a few:

1. Intel BLKD201GLY Mini-ITX + Celeron M 215: $75.00
CPU: Intel Celeron M 215: 1.33 GHz, 533 MHz FSB, 1024 KB L2 in a BGA setup (soldered to board) ~25 W CPU TDP
RAM: One desktop DDR2-667 or -533 module up to 1 GB
Chipset: SiS SiS662/SiS964L
Graphics: Integrated SiS
Ports: 6 USB 2.0, one of each serial, parallel, PATA, SVHS, RGB, PCI, PS/2 kbd and mouse.
NIC: 100 Mbps Broadcom LAN

2. JetWay J627F800 Mini-ITX: $79.99
CPU: VIA C3 @ 800 MHz, 128 KB L2, 100/133 MHz FSB in a BGA setup (soldered to board) approx 10 W CPU TDP
RAM: One desktop DDR-266 up to 1 GB
Chipset: VIA CLE266/VT8235
Graphics: S3 UniChrome integrated
Ports: 2x USB 2.0, 2x PATA, one serial, PCI, PS/2 kbd. and mouse, 2 headers for 4 more USB ports
NIC: 100 Mbps VIA VT6103

3. JetWay J7F2WE1G Mini-ITX: $134.99
CPU: VIA C7 @ 1.00 GHz, 128 KB L2, 133 MHz FSB in a BGA setup (soldered to board) 9 W CPU TDP
RAM: One desktop DDR2-400 up to 1 GB
Chipset: VIA CN700/VT8237RP
Graphics: S3 UniChrome integrated
Ports: 2x USB 2.0, 2x PATA, 2x SATA-150, PCI, AD expansion daughter board slot, PS/2 kbd. and mouse, serial, RCA TV-out, 2 USB headers for 4 more USB ports.
NIC: 100 Mbps VIA VT1617A

4. VIA/VPSD EPIA-CN10000EG Mini-ITX: $174.99
CPU: VIA C7 @ 1.00 GHz, 128 KB L2, 133 MHz FSB in a BGA setup, ~5 W TDP *completely passively cooled*
RAM: One desktop DDR2-533 up to 1 GB
Chipset: VIA CN700/VT8237R
Graphics: S3 UniChrome integrated
Ports: 4x USB 2.0, 2x PATA, 2x SATA-150, one serial, PCI, SVHS, RCA TV-out, PS/2 kbd. and mouse, headers for 4 more USB 2.0 ports
NIC: 100 Mbps VIA VT1603

These will all be more than powerful enough to handle audio playback and will be significantly smaller and less power-hungry than a regular desktop CPU and motherboard. All but the last one is less expensive than a lower-end CPU + an okay motherboard as well.

The Via's, Celerons, and single-core Athlons/Semprons are all good for low power/passive cooling needs, and would be fine for audio playback, if that was all you need to do. If you intend to record/play back video, I would recommend going with a BE-2300/2350, a 65nm X2 3600/3800, or a low-cost Core 2 Duo or Pentium Dual Core (make sure it is a Pentium Dual Core, not the Pentium D, as the former is a re-branded low-end Core 2 Duo while the latter is a heat and power monster). The single-core processors don't have enough capability to encode/decode HD video (only important if you plan on recording and playing back HD video).

You want the newest intel core 2 since they run so cool you can use a very slow moving fan to cool them.

i think the be series from amd or the e4000 series from intel are good choices for an htpc with the edge going to the be series because of how bloody cheap it is. do you plan on playing hd content with this htpc by the way?

I have just built one with AM2 3800+X2 EE (35W), AMD690G MB and 512MB RAM. Using CoreAVC, this just has enough power to playback full-HD content (although I am now preffereing 720p, as that is native resolution of my projector).

I guess there is right now no better option. The important think is that AM2 platform is the only one to provide motherboards with DVI output. All that fun costed less than $400 (DVB-T card included).

The only mistake I have done is 3.5" 320MB HD, because it is the only source of noise in the system. I will replace that soon with some quiet 2.5" notebook drive and move 320MB to home network server - would be cheaper too..

The problem with Intel and HTPC is the lack of cheap micro-atx motherboards with DVI-I (essential for good playback IMO).

You can get AMD690G with DVI-I AND 3800X2 CPU for less than e4000 series CPU alone. And you would need separate video card for Intel to get DVI-I. And it is enough to play HD (and cool and quite too...).

yeah i definitely prefer amd for budget and htpc builds because intel boards are just so expensive. one potential caveat i could see is that wouldnt using integrated graphics increase processor utilization and therefore cause a wind turbine like noise? probably a moot point if you passively cool it anyway but its just a thought considering most htpc cases don't have the clearance required for a massive heatpipe tower like the ninja.

digit-life did some measurements that disagree with those rankings:

http://www.digit-life.com/articles [...] page3.html

There are cheap AsRock motherboards that offer DVI built-in through a riser card. And you don't need to get a E4000 series CPU, the Pentium E2100s are more comparable in pricing and performance, while running considerably cooler.

Digit-Life compared the Pentium Dual Core vs. the BE-2350, not the Celeron D 400. The Celeron is a single-core chip and will trail the BE-2350 in the video and audio encoding tasks such as the ones Digit-Life performed.

The power consumption figures look a bit odd to me. I am betting they jacked into the VRM input, which means that the VRM affects the measurements. The NF590-SLi in the M2N32-SLi is a much less efficient board than the P965 in the P5B Deluxe and I am certain that is affecting the values of the draw for the BE somewhat. It does show that the Pentium Dual Cores are very efficient, but I'd like to see those results for the BE on a different board. A 17-watt idle for an X2 is a little high for one at that voltage and clock speed, other X2s on other websites are more like 10 watts at idle. I suspect the 590 SLi has a VRM mapping that's tuned much more to deliver a bazillion watts to X2 6000s and FX-62s rather than be efficient.

So I guess the moral of this story is that the motherboard affects the measurements quite a bit. I remember seeing an article on VRMs and number of phases and the different VRM setups caused differences in draws like this. Whatever board you do decide to get, pick one with 3 or 4 phases, not 6 or 8 as the extra ones are not needed (you have a low-draw chip) and will just suck up extra power.