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Posted: Mon Feb 27, 2006 7:47 pm
by TomZ
V = I * R must always be satisfied. Thus, if you increase the voltage, you get a proportional increase in current.
Given Power = V * I, you see how you end up with the V^2 relationship.
Power in this case is related to energy stored in a capacitor (the CMOS gates), which is U = (1/2)CV^2. Multiplying by frequency gives the power, thus (1/2)fCV^2.

Posted: Sun Mar 05, 2006 8:24 am
by Operandi
I realize that AMD is preferred right now by default for obvious reasons but if anyone has some experience on the Intel side of things that they would like to share we could really use some Pentium 4 and M board recommendations.
defaultluser wrote:And, just to stay on-topic, my Asus A8V Deluxe is fully passive, and runs cool. Sure, it's not exactly new, and yes, it lacks PCIe, but you can still pick them up. Two Q-fan controlled headers, with voltages as low as 9/16 * 12v. Undervolting.
I already have the Asus A8V in the list.

Posted: Sun Mar 05, 2006 9:00 am
by jaganath
we could really use some Pentium 4 and M board recommendations.
For Pentium M on the desktop there are only really four choices: the Aopen i915GM-HFS, DFI 855GME-MGF, MSI 915GM Speedster-FA4 or one of the Asus boards which is approved for use with the CT-479 adapter.

For Pentium 4, take your pick from the boards listed in the Undervoltable Motherboards article and thread.

passively cooled motherboards

Posted: Sun Mar 05, 2006 3:59 pm
by cmthomson
I'm a bit surprised nobody has mentioned the ASUS P5LD2 775 motherboard.

It's completely passive, with large heatsinks on the Vcore and north bridge, and a small heat sink on the south bridge. It appears to be designed to take advantage of the downwash from the stock Pentium D HSF to cool the MB components... My setup uses a Ninja instead, and the MB components get pretty hot; there is very little direct airflow onto the MB heat sinks.

Anyway, even with a suboptimal :oops: CPU HS, this MB works well for me.

Posted: Mon Mar 13, 2006 11:34 am
by Operandi
Abit AT8 based on the ATI Xpress 200 and ULi M1573 chipsets has been added. It looks like an interesting board; completely passive and apparently control for all six fan headers, nice stuff! Undervolting controls unknown.

Also added is the AOpen i945Ga-PLF, a modern full featured board for the P4. With AOpen's Power Master it's probably one of best boards if you are set on Pentium4 platform.
cmthomson wrote:I'm a bit surprised nobody has mentioned the ASUS P5LD2 775 motherboard.
I'd be happy to add it. Its passive which is good, just need some info on fan control and CPU core voltage control.

Posted: Thu Mar 16, 2006 8:21 pm
by cmthomson
operandi wrote:...
cmthomson wrote:I'm a bit surprised nobody has mentioned the ASUS P5LD2 775 motherboard.
I'd be happy to add it. Its passive which is good, just need some info on fan control and CPU core voltage control.
The P5LD2 has one 4-pin fan header for the CPU fan. It has Q-fan control (which with the stock Intel cooler is never Q) tied to the CPU thermal diode. It has three other 3-pin fan headers (12V plus speed sensor).

The CPU core voltage can be adjusted from 1.275V to 1.7V in 0.0125V increments. The MCH, ICH and DRAM voltages are also adjustable.

The manual for this MB can be found here:
http://dlsvr03.asus.com/pub/ASUS/mb/soc ... _p5ld2.pdf

Two caveats: this MB is designed for a CPU HSF that blows down onto the MB; if you use a Ninja or other tower, the MB components may overheat. Also, the Vcore voltage droops under heavy load (eg, P830D running 2xCPUBurn).

If you use an Intel CPU with 775 LGA, especially one with a TDP less than 100W, take a look at the P5LD2 MB.

Posted: Mon Mar 20, 2006 11:01 am
by Operandi
cmthomson; the P5LD2 has been added. Is the CPU fan header the only one that is controlled by Q-Fan? What about SpeedFan support?

Posted: Mon Mar 20, 2006 11:27 am
by cmthomson
operandi wrote:P5LD2 added. Is the CPU fan header the only one that is controlled by Q-Fan? What about SpeedFan support?
Yes, only one fan header has speed control. All four have speed sensing.

SpeedFan can read all four fan speeds, the CPU and MB temperature, the HDD temperatures if they have SMART, and the Vcore, 12V and 3.3V voltages. It has an "automatic fan speed" checkbox that I can check, but since I run (slow) constant speed fans, I've never tried using that feature.

BTW, the P5LD2 has the 945P MCH, not 945G.

Posted: Fri Apr 07, 2006 4:40 am
by inti
Some passively cooled socket 939 boards for further research: I do not know what undervolting options these have, nor what fan headers can be found on the board (seems a less important requirement)

Abit AN8-32X nForce4/SLI is passively cooled. It is a costly full-featured board, seems extremely similar in features and layout to the Asus A8N32-SLI Deluxe.

As other members have commented, some of the widely available Gigabyte K8N series of Socket 939 boards are passively cooled:

Gigabyte GA-K8N SLI is a passively cooled nForce4/SLI board at a mid-price. There is also a widely available 'Pro-SLI' version (almost the same but adds Firewire) and an 'Ultra SLI' version: I think the differences in the Ultra version are four more SATA ports on a Sil3114 chip and an extra Gigabit ethernet socket. There was an older K8NXP-SLI version which had an actively cooled Northbridge, and some international versions offer the passive heatsink with an add-on fan which fits over the top - all very confusing, so just be careful which one you get. (Note that some models have an optional PCI audio card which has a small fan on it.) This board can undervolt the CPU down to 0.800V I believe.

(Do not confuse this with the Gigabyte GA-K8NF-9 which is non-SLI, has a Northbridge fan and is not easily moddable as the Northbridge is right under the graphics card slot)

Gigabyte also do three fanless micro-ATX boards (with various integrated graphics solutions), for example Gigabyte GA-K8N51GMF-9. I doubt that these would allow undervolting.

MSI do a similar fanless micro-ATX board with integrated nV6150 graphics, named the MSI K8NGM2-FID. I do not know about undervolting.

EPoX EP-9HDAI-Pro is passively cooled; it is one of those AGP/Socket 939 boards for your legacy graphics card, VIA K8T800 Pro chipset and budget price.

Posted: Sun Apr 09, 2006 11:52 am
by Operandi
inti wrote:Some passively cooled socket 939 boards for further research: I do not know what undervolting options these have, nor what fan headers can be found on the board (seems a less important requirement)
For me personally fan control is the most important requirement; undervolting doesn’t interest me, and it's easy enough to find passive boards without this thread if that’s your only concern.
inti wrote:Abit AN8-32X nForce4/SLI is passively cooled. It is a costly full-featured board, seems extremely similar in features and layout to the Asus A8N32-SLI Deluxe.
I'll look into the AN8-32, since I'm fairly certain all Abit boards use the same FanEQ control.
inti wrote:As other members have commented, some of the widely available Gigabyte K8N series of Socket 939 boards are passively cooled:
I'd be happy to add the Gigabyte boards. I just need some general information regarding fan control. I would like at least the CPU fan header controllable to make it to the list....

Posted: Mon Apr 10, 2006 5:24 am
by inti
This is to confirm that the Gigabyte K8N series that I mentioned have active fan control on the motherboard, which is linked in with AMD's 'Cool N Quiet' feature (link to SPCR article. It is called Gigabyte "Smart Fan" and there is BIOS control with five settings: Off, Low, Mid, High and Full and user-configurable temperature threshold and speed for each.

Personally the main problem I have with most motherboard fan controllers is they give the fans too many volts, the usual range is around 7V to 12V while I would prefer something like nil to 6V. If you're handy with a soldering iron and have a few Zener diodes in your cabinet then no problem, of course. It may be that the latest Gigabyte "Smart Fan" which allows you to control fan speed (voltage) for each setting will finally overcome this problem.

I am looking to buy a motherboard for my server this week and for me it is a narrow choice between the Gigabyte K8N SLI Ultra and one of the DFI boards. The Gigabyte is better value (especially with 8 included SATA data and power cables) but I am concerned about the passive cooling, reviews suggest it runs so hot that it might need a fan adding there in which case the DFI pre-installed fan might actually be quieter.

Posted: Mon Apr 10, 2006 9:29 am
by inti
(Note: any nForce4 board may have serious issues with certain models of Maxtor Diamondmax 10 and Diamondmax 11 SATA drives. Maxtor have updated the BIOS but downloading and installing it is a pain, and you have to back up your entire drive first. nVidia have not updated their BIOS yet.)

Whether you have Maxtor drives or not, it is well worth looking at the various ATI (Crossfire) boards. These are mostly passively cooled, and the northbridge and southbridge draw less power and run at lower temperatures than nForce4 equivalents: especially cool-running are the newest RD580 based boards which draw 8W apparently. (There are two main northbridge versions, the one-year-old RD480 and the new RD580. These can be paired with southbridges from ATI or from third party manufacturers.)

DFI RDX200 - the original RD480-based ATI board, troubled by a slow PCI bus so tends to have data transfer speeds 20%-30% slower than average for USB hard drives (including iPod etc), Firewire and Gigabit Ethernet, also some SATA bottlenecks (and no SATA II). On the other hand for general computing and gaming it is fast, and it is a feature-filled board with good audio, dual Gigabit ethernet, 8 SATA ports, and being a DFI board it is very flexible for overclocking or undervolting whichever you prefer. Actively cooled but quiet.

DFI CFX3200 - is the just-released RD580 replacement from DFI, seems to be very fully featured but no reviews yet.

Asus A8R32-MVP Deluxe - RD580 based, an excellent overclocker, CPU Vcore fully adjustable down to 0.800V, cool running passive northbridge and southbridge, fully-featured with dual GigE, 5 SATA ports and one external, good audio, Firewire and all other usual inputs and outputs. This has received excellent reviews. Only the CPU-fan socket is temperature controlled and the control of that is fairly basic, just two settings low and high. User reports on other forums indicate compatibility with Scythe Ninja.

Asus A8R-MVP - RD480 based, good overclocker or undervolter, single GigE and 4 SATA ports.

Comparative review of the Asus A8R-MVP and the DFI RDX200 boards, and a standard nForce4 board

MSI RD480 Neo2 - (already in the list) - a mid-priced ATI board, fewer features (only 1 Gig Ethernet), like others it has good audio and good overclocking potential, but like several other MSI boards it appears to offer CPU overvolting only, no undervolting (can anyone confirm?)

Abit AT8 - (already in the list) - a well-laid out board with a passive heatpipe based cooler for the northbridge and southbridge, excellent fan control (see comments above), chosen by several SPCR members but ruled out for me because it omits a coaxial SPDIF socket - therefore useless for home theatre. Other SPCR members are using with a Scythe Ninja.

(I'm still researching if any of these boards are incompatible with large heatsinks such as Scythe Ninja or the Thermalright models - some passively cooled ATI boards may have a problem due to the large size of the northbridge heatsink, but no problems with the Asus and Abit boards noted.)

Posted: Mon Apr 10, 2006 9:52 am
by Firetech
inti wrote:Also well worth looking at the various ATI (Crossfire) boards. These are mostly passively cooled, and the northbridge and southbridge draw less power and run at lower temperatures than nForce4 equivalents: especially cool-running are the newest RD580 based boards which draw 8W apparently. (There are two main northbridge versions, the one-year-old RD480 and the new RD580. These can be paired with southbridges from ATI or from third party manufacturers.)

DFI CFX3200 - is the just-released RD580 replacement from DFI, seems to be very fully featured but no reviews yet.
Arghh, another DFI chipset fan :evil: Nice work inti 8)

I'd be very careful with Crossfire boards as there are lots of reported issues. Many are admittedly overclocking related but some are component compatability issues too ie memory. Worth researching on forums before buying (many website reviews have missed issues or only 'discovered' them later) That said, I like the look of the Abit AT8 32X but am awaiting further specialist forum feedback on it. :D

Posted: Mon Apr 10, 2006 10:05 am
by inti
Yes, one must always be a bit brave to be an early adopter of the first board using a new chipset. But as you say, I think a lot of the 'noise' on forums is overclocking related, for example people who haven't been able to push the bus speed above 250MHz - and who knows whether the cause is the motherboard, or their CPU, or their memory, or their PSU, or just a question of technique? For example, the following review indicates that the A8R32-MVP Deluxe is a 'quirky' overclocker needing a cold boot to respond to changes to the HyperTransport bus speed
http://www.neoseeker.com/Articles/Hardw ... vp/13.html

Posted: Mon Apr 17, 2006 9:53 am
by Operandi
Thanks for the excellent post inti. I've added the Asus A8R32 which looks like excellent board; just too bad about the poor fan control, can you confirm that for me and/or provide SpeedFan information?

I saw your entries for the DFI RDX200 and Asus A8R-MVP but I think I'll pass on adding them since they are already or will soon both be eclipsed by boards based on ATIs new chipsets.

Posted: Wed Apr 26, 2006 9:24 am
by ceselb
inti wrote:Asus A8R32-MVP Deluxe [...] User reports on other forums indicate compatibility with Scythe Ninja.
Really? I've tried to verify this but no luck so far, can you give some links?

Posted: Wed Apr 26, 2006 11:09 pm
by mattthemuppet
I compiled an excel spreadsheet based on the Recommended Mobo list, with speedfan support w/ no. of headers. It's about a year old (or more) but it may still be valid - PM me if you want it :)

Asus A8N5X

Posted: Sun Apr 30, 2006 10:22 am
by defaultluser
I just recently upgraded to an Asus A8N5X. After some modifications, it is an excellent board for an excellent price (less than 80 bucks!).

The good:

* VERY cheap nForce 4 board

The bad:

* 6000 RPM screamer cooling the chipset
* Because of the low price, only the CPU fan has Q-fan support. ASUS has disabled fan control for all other headers, even with Speedfan.

The compromise:

* Installed a Zalman passiver northbridge cooler, DOES NOT INTERFERE with PCIe 16x 7900 GT.
* Installed a 120mm Scythe 800 RPM liquid bearing front intake fan, DEAD silent.

It works very well, Q-fan is better than on my old ASUS A8V, because now it starts at a much lower voltage, and you have control over the "target" temperature that the sensor should never be allowed to reach. If you want it to be hot but quiet, you can set the target to 80 or 90C...the default is 75C, and it is fine.

Posted: Sun Apr 30, 2006 3:24 pm
by Operandi
Boards are now also broken down by socket and chipset.

Edited the entry for the Asus A8R32-MVP Q-Fan properties since I've later learned that the chassis fan as well as the CPU fan is controlled by Q-Fan. The control is also far more then "on or off" with "fan start temp" as well as "fan max speed temp", with ranges from 0-100c. :P

Asus A8N5X has been added.
mattthemuppet wrote:I compiled an excel spreadsheet based on the Recommended Mobo list, with speedfan support w/ no. of headers. It's about a year old (or more) but it may still be valid - PM me if you want it :)
Probably not unless it pertains to boards already on the list. I'd like to keep the list streamlined and to modern boards that you can still purchase.

Posted: Sun Apr 30, 2006 6:25 pm
by MikeC
Helped out with a quick entry about the DFI RS482. Very nice mATX board for silencers.

Posted: Sun Apr 30, 2006 6:57 pm
by Operandi
MikeC wrote:Helped out with a quick entry about the DFI RS482. Very nice mATX board for silencers.
Looks good, thanks. :wink:

Posted: Sun Apr 30, 2006 7:10 pm
by Dutch2
Not "quietness" related, but I wouldn't recommend the ABIT AT8 if you plan to use SATA RAID.

Even with the latest BIOS and latest drivers, there is a RAID0 data corruption issue.

To make matters worse, ABIT technical support is using the "ignore-them-and-they-will-go-away" tactic :evil:

D2.

Posted: Mon May 01, 2006 5:16 pm
by J_PC
The A8N5X Manual lists CPU voltage settings from 0.800 to 1.650 Volts in 0.0125 V increments. I just ordered one, so I haven't actually had the chance to test it.
Asus A8N5X -- ATX / 939 / nForce4 -- Active cooling is stock but ample room is provided for large passive heatsinks. -- Q-Fan control for CPU fan header with selectable target temp. -- SpeedFan supported -- CPU under-volting unknown

Posted: Mon May 01, 2006 7:10 pm
by Zacchino
What about the p5wdg2-ws from Asus ?

Anyone experienced heat issues with this one (or other issues) ?

Posted: Tue May 02, 2006 4:45 am
by inti
@ceselb, I've posted a mini-review of the Asus A8R32-MVP on your other thread, and I can confirm Scythe Ninja compatibility: see here: http://forums.silentpcreview.com/viewto ... 416#263416

Posted: Tue May 02, 2006 8:02 am
by Operandi
J_PC wrote:The A8N5X Manual lists CPU voltage settings from 0.800 to 1.650 Volts in 0.0125 V increments. I just ordered one, so I haven't actually had the chance to test it.
Asus A8N5X -- ATX / 939 / nForce4 -- Active cooling is stock but ample room is provided for large passive heatsinks. -- Q-Fan control for CPU fan header with selectable target temp. -- SpeedFan supported -- CPU under-volting unknown
Roger that :) .

Posted: Tue May 02, 2006 8:09 am
by nutball
inti wrote:This is to confirm that the Gigabyte K8N series that I mentioned have active fan control on the motherboard, which is linked in with AMD's 'Cool N Quiet' feature (link to SPCR article. It is called Gigabyte "Smart Fan" and there is BIOS control with five settings: Off, Low, Mid, High and Full and user-configurable temperature threshold and speed for each.
They do indeed have this feature -- though personally I've not had a great deal of luck getting it to work on my K8N-SLI. Neither BIOS control nor Speedfan wanted to shift the RPMs on my CPU fan (yes it was a three-wire fan)... so I resorted to a Fan-mate and gave up with the software control.

The RPM readout from Speedfan is a little intermittent too, especially below 700RPM.

Posted: Wed May 10, 2006 4:15 am
by =assassin=
inti wrote: (Do not confuse this with the Gigabyte GA-K8NF-9 which is non-SLI, has a Northbridge fan and is not easily moddable as the Northbridge is right under the graphics card slot)


My dad's K8NF-9 (bought in March 2005) is passive? It's even got the picture as passive on Gigabyte's site? It was originally active when first released, but it was changed almost straightaway?

Re: Asus A8N5X

Posted: Wed May 10, 2006 6:05 am
by Sparkytfl
defaultluser wrote:I just recently upgraded to an Asus A8N5X.
The bad:
* Because of the low price, only the CPU fan has Q-fan support. ASUS has disabled fan control for all other headers, even with Speedfan.
That sucks. The first page says speedfan compatible, which is a bit misleading then. I have this board due to arrive today. I was going to have water cooling on the cpu, video, and chipset, and let speedfan deal with my two case fans. I suppose one could connect to cpu header.

Also I wish people would stop recommending the a8rmvp. Until asus puts out a stable bios for it, it's worthless.

Posted: Sun May 28, 2006 5:53 am
by Number12
operandi wrote: I already have the Asus A8V in the list.
I'm not sure whether the A8V is any different from the A8V Deluxe (the Asus website is broken atm). However, Speedfan works well on the A8V Deluxe on the 2 fan headers supported by Q-Fan. CPU undervoltable to 0.80VCore. Dual core updated BIOS. RMClock works well for dynamic underclocking and undervolting.

I also have the Asus A8N-SLI Deluxe. Dual PCIe, speedfan enabled on 2/4 fan headers, CPU undervoltable to 0.80VCore, RMClock also works well. NB fan has been swapped with a zalman NB32K with lots of clearance with my 6600GT (can't vouch for longer video cards, though).