I am interested in building approximately 4 quiet PC's for use with Windows MCE.

It seems logical that using a Turion (that should fit in any sociket 754 desktop motherboard) would be a simple way to create a very low power basic system with the potential to be passively cooled.

I understand from reading the posts that:

1) there is no heat spreader on the Turion so the CPU coller will have to adjust to fit directly on top of the processor
2) the Turion 25W processors use 1.2 Volts and the motherboard needs to support this voltage
3) there is little point to using the Turion on a motherboard that does not support Cool N Quiet because the power management that the CPU supports will not be fully used

It sounds as if most of the currently produced socket 754 motherboards will support the newer 90 nm processors so that in theory they should generally support a Turion but also that some people have reported problems with manually setting key processor variables (like the voltage) because the motherboard does not recognize or officially support the processor.

Motherboards with integrated graphics are appealing for cost reasons and because they are typically passively cooled. If I limit my search to these products I am limited to motherboards based on the ATI Radeon Express or Nvidia 6100 series chipsets (that support Directx 9 graphics).

I am wondering if anyone can report any real world success with a Turion installed on any desktop motherboard based on these chipsets?

Thanks in advance for any advice and if you can point me to a thread I may have missed or another source of this information, I would be grateful.

I can't comment on any 6100/6150 or RS480-based motherboards, but I can tell you that my Turion works very well with a DFI Lanparty UT nF3 250Gb.

To be honest, though, with the Sempron64s available for Socket 754, I really think it's hard to justify buying a Turion. The Sempron64s are cheap, 90nm, should have similar power characteristics to Turion when undervolted, and have SSE3 and 64-bit instructions. All you really lose is the cache, which makes little difference in most applications.

has anybody had any luck with a m/b based on the uli 1689 or 1695 chipsets and a turion? or any other passively cooled m/b?

i am looking at replacing my P4 C 3.0GHz desktop but still have similiar procesing power with a ultra low power/heat machine being that i live in phx, az and in the summer my computer room will hit ~87F when the rest of my condo is 78F. i am willing to give up some cpu power in order to save in the heat/power department.

currently i don't do much hardcore cpu intensive apps besides dvd encoding occasionally, but if i need to i can leave the machine on all night as i have not been doing much in the video creation arena. besides, my rig is ~1.5yrs old and i know the knew a64s-m/turions and p-ms really have a lot of power per cpu cycle.

i game too (bf2) and run 1GB PC3200 with a x800xtpe gpu.

i just got notice from my electric company that they are going to r@pe me for 30% more soon...

Thanks for the information

I know that the newer Sempron processors are quite similar to the Turion processors but their reported power consumption is quite different with the low power Turions reported to consume a max of 25W while the Semprons are more than 60W. Is this just marketing and the actual power consumption is really comparable or do the Turion processors have an advantage?

I realize that an under-volted Sempron may consume a lot less power but does it actually put it under 25W or does it simply lower consumption to 40W or so? While both of these numbers are low, I am worry that the difference between 25W and 40W may be enough to prevent passive cooling from working under some circumstances.

Again, thanks for any advice and it would be great to hear if anyone else has suceessfully run a Turion on a desktop motherboard...

AMD's desktop TDP ratings are very conservative. Consider that the 90nm mobile Semprons run at a voltage of 1.25V and are rated for 25w. A lower-end Sempron should have no problem undervolting to ~1.05V. Based on AMD's 25w rating @ 1.25V, we can calculate a TDP of ~17w @ 1.05V. Not quite the performance/watt of a Turion, but still very good IMHO.

To calculate power:

( V1^2 / W1 ) = ( V2^2 / W2 )

V1 = Original voltage
W1 = Original power
V2 = New voltage
W2 = New power

Thanks for the additional information.

Are you describing the mobile Sempron or is a plain vanilla 90nm Sempron also undervoltable (is this a word?) to consume less than 20W when set up properly.

If it has to be a mobile Sempron to get this kind of power use, do you recommend a source for these processors? I can easily locate Turion Processors for sale but not the mobile Sempron.

As far as I know the mobile Semprons are just desktop Semprons rated for a lower voltage. The Turions are the only AMD processors designed for laptop use.

So you should be able to undervolt a desktop Sempron to 1.25V and have a ~25w processor. Same goes for the ~17w figure @ 1.05V. But keep in mind this is TDP, which is not typical power, but maximum power consumption under worse-case conditions. Under normal conditions, power consumption may only be 14w, for example, at 1.05V.

Is undervolting part of what Cool N Quiet does? If I undervolt the processor, will Cool N Quiet have to be disabled? I know that the processor clock is also slowed under Cool N Quiet. I guess my question is really how do the following options compare?:

1) a 25W Turion with Cool N Quiet enabled (currently $210 for MT-34)
2) a desktop Sempron with Cool N Quiet enabled (currently $87 for 3000+)
3) a desktop Sempron that is undervolted (and may not work with Cool N Quiet) (currently $87 for 3000+)
4) a mobile Sempron with Cool N Quiet enabled (currently $93 for 3000+)

If I understand what you have said before perhaps options 2,3 and 4 are identical except some processors are "rated" to operate at lower voltages. How important is this rating? If a desktop motherboard does not properly identify the mobile processors and the voltage has to be set manually, will this automatically disable the functionality of Cool N Quiet?

Thanks again for any help or advice

I'd go for option #5: Desktop Sempron64 undervolted in the BIOS with software CnQ (using a program such as CrystalCPUID, for example). Also, why not grab a 2500+/2600+ Sempron64? Should be more than enough power for an HTPC, I'd think.

The Turion may be slightly more power friendly, but considering the price and difficulty of getting one up and running (potential motherboard and heatsink conflicts), I don't think it's worth it, especially if you just don't really need the extra performance the Turion has to offer.

is anybody sure of which other boards definately work with the lower voltages like 1.25-1.0V? i know the dfi does and i have read that a soltek based on the nf3 250gb chipset will, but is there anything else?

The Turion should work on Asus K8V SE (VIA K8T800), undervolting should be possible too. I read that some people use Mobile Athlon64s (35-TDP-Watt) on this motherboard.

I plan to do the same as you want, to put a Turion64 MT in a desktop-machine. What should I do first:

1. Buy a 19 inch TFT
or
2. Buy a Turion 64 MT-30 (an overclock it)?

bullshit language

thanks, i like the price of that board, anybody know if the uli1689/1695 will work?

My advice is not to use a mobile chip in a desktop. I went that route a while back and got a Mobile Athlon64 (sock754) and used it in a desktop. It worked, but I recently had to buy a new motherboard because the SATA controller crapped out.

Brand new motherboard - and it doesn't support the mobile part - won't even power it up. Had to dump $75 on a sempron64 (sock754).

Passive cooling is overrated. I've got an X2 3800+ and an XP-120, and even overclocked to 2.2GHz it idles at 26-27c and it's very quiet. You can build an effectively silent PC without using risky mobile parts, and you'll have fewer compatibility issues.

Myself, I would go with Venice 3000+, $145 or so, cool and quiet, undervolt if you want to go with ultra quiet cooling.

my goal is not due to noise, but power and heat.

s for hdds, i run either pata or scsi (never had either type of controller take a sH!t on me in the 10years i have been building computers, not to say it doesn't happen though)

Also, I tried my Turion in an ASUS K8V-X SE. It worked, but not perfectly. Vcore was "stuck" at ~1.3V in the BIOS, and the only way to change it was with software inside Windows. I was using the latest BIOS (this was probably 2-3 months ago).

looks like i need to look for a used dfi nf3 250gb......thanks for the info.

frostedflakes - do you recommend any certain board for this setup of using a sempron 64 and CnQ? my luck at finding a 35W xp-m for a different app is not going well and this may be the way to go for me since anybody who has a 35W xp-m wants a mint. also, what would you say the amount you could lower the tdp by? could i get a sempron64 to go down to ~35W? it will be replacing a xp2000 so processing power is not too important.

also, does this CnQ program work stable enough for server use (albeit home server)

thanks

Don't worry too much about the TDP. Like said before, AMD's TDP is very conservative which is true for AXP, mobile AXP, mobile A64, mobile Sempron and T64. The TDP of todays desktop CPU's (Sempron, A64 and possibly Opteron) are worse than that, they seem to be completely wrong.

My classic example is to compare a mobile A64 3000+ (2 GHz, 1.35 V, 35 W TDP) with a 3500+ (2.2 GHz, 1.4 V, 67 W TDP), both revision D. You see the inconsequence? They can't both be right, and AMD wouldn't put a TDP lower than it is, so it should be 41 W for the 3500+. 31 W measured on a 3800+E under Prime. 48 W measured on the mobo with a 3500+E under CPUBurn. The TDP of a mobile is closer to the truth IMO, that's why you can't compare the TDP of a T64 and a Sempron. Here's an example of what you can do with an A64.

Forget about T64, go for Sempron and put the money on a good mobo (=UNDERVOLTING IN BIOS). Remember that some Semprons (if not all) slower than 1800 MHz don't support cool 'n' quiet. Not really a problem though...

i was reading more about that program and it says it supports nf2 and axps, could i use it safely with my xp2000? and try to get it lower?\

[edit]guess not, as mine is not unlocked...

frostedflakes - if i unlocked my xp2000, which i think is just connecting a bridge, how low(V and MHz) do you think i could get it down using the crystalreports cnq program? is there any way i could it down to ~35W at it slowest and then ramp it up to 100% when needed? this machine is probably at 100% 5% of the time it is up....

To be honest, I really don't know much about AthlonXP power usage and undervoltability. All I've really read up on is Athlon64 stuff. Sorry.

I was curious, isn't multiplier being unlocked one of the appealing features of putting a mobile 64 into a desktop system? I may be talking baloney here, as I'm quite behind on the while A64/A64 mobile/turion area.

-Ken

All K8, whether mobile or desktop, are "half-locked," meaning all multipliers lower than stock are available. So it's not like the mobile AthlonXPs, which were fully unlocked.

Except for Sempron 2500+, 2600+ and 2800+, dunno if it's the same for newer ones though.
I could only adjust the multiplier with software on my AXP 2500+, not Vcore. It turned out pretty useless for me since it meant that I needed to use high Vcore all the time.

Very great news for me, as I thought I needed a mobile 64 to undervolt/clock as I do now with my AXP (1.1vcore...passively cooled). Half-locked works for me, of course I'll still do additional reading before upgrading.

-Ken

which axp are you running and and at what mhz @ 1.1V. what m/b? also have you used the crystalcpuid to change the frequency on the fly as needed by uses?

Yeah, it was wierd. I'm semi-convinced the Fedora 4 kernel somehow did it. I booted up to reinstall OS, BIOS recognized disks fine. Booted into OS, and OS saw them. Next reboot, BIOS didn't see disks, and Linux actually hung.

Out of curiosity, why would you care about power and heat except in terms of noise required to cool? Either way - I'd just get a normal desktop CPU and undervolt it if that's your concern - it's the same thing the mobile chip does, and you'll have fewer compatibility issues.

my concern for power and heat are the fact that i live in phx az and have 3 desktops and 1 laptop in my computer room. my server machine stays on 24/7. my computer is about 10F hotter than the rest of the condo, even as i write this at 10PM my computer room is still 78F and we dont use the heater and for about 7mos out of the year my computer room will stay at about 85+F, which require me to keep the condo air set on more to keep the room bearable.

second that with the fact that my summer electric bills are ~$250+ easily and my electric company is planning on a ~30% raise in the near future is what has gotten me into this scenario.

from all the reading i have done, what you suggest is probably the easiest/cost effect way to go and use crystalcpuid to vary the V and MHz as needed....

does anybody know the best cpu/chipset do this with, as far as skt754, 939? or does it matter? is the crystalcpuid program stable enough for home server duty?

I have seen this limitation in the adjustability of these processors discussed a couple of times and have questions:

1) are the newer Sempron processors based on the 90nm core functional with Cool N Quiet for processors rated <3000 (2500+, 2600+ and 2800+)?

2) even if the newer processors are Cool N Quiet capable, is it possible that this support will be disabled by the motherboard Bios?

thanks.

1. All 32-bit only Sempron 2500+ - 2800+ are totally locked, menaing no CnQ. It is possible that the newer Sempron 64 that supports it, but I'm not sure. All desktop K8's manufactured today supports 64-bit.

2. I can't answer for all mobos ever made but in general, no.